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system.events

Querying in ClickHouse Cloud

The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the clusterAllReplicas function. See here for further details.

Description​

Contains information about the number of events that have occurred in the system. For example, in the table, you can find how many SELECT queries were processed since the ClickHouse server started.

Columns​

  • event (String) — Event name.
  • value (UInt64) — Number of events occurred.
  • description (String) — Event description.

Example​

SELECT * FROM system.events LIMIT 5

┌─event─────────────────────────────────┬─value─┬─description────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ Query                                 │    12 │ Number of queries to be interpreted and potentially executed. Does not include queries that failed to parse or were rejected due to AST size limits, quota limits or limits on the number of simultaneously running queries. May include internal queries initiated by ClickHouse itself. Does not count subqueries.                  │
│ SelectQuery                           │     8 │ Same as Query, but only for SELECT queries.                                                                                                                                                                                                                │
│ FileOpen                              │    73 │ Number of files opened.                                                                                                                                                                                                                                    │
│ ReadBufferFromFileDescriptorRead      │   155 │ Number of reads (read/pread) from a file descriptor. Does not include sockets.                                                                                                                                                                             │
│ ReadBufferFromFileDescriptorReadBytes │  9931 │ Number of bytes read from file descriptors. If the file is compressed, this will show the compressed data size.                                                                                                                                              │
└───────────────────────────────────────┴───────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

See Also​

Event descriptions​

ACMEAPIRequests​

Number of ACME API requests issued.

ACMECertificateOrders​

Number of ACME certificate orders issued.

AIAPICalls​

Number of HTTP requests dispatched to AI providers.

AIInputTokens​

Total prompt tokens consumed across all AI function calls in the query.

AIORead​

Number of reads with Linux or FreeBSD AIO interface

AIOReadBytes​

Number of bytes read with Linux or FreeBSD AIO interface

AIOWrite​

Number of writes with Linux or FreeBSD AIO interface

AIOWriteBytes​

Number of bytes written with Linux or FreeBSD AIO interface

AIOutputTokens​

Total completion tokens consumed across all AI function calls in the query.

AIRowsProcessed​

Number of rows that received an AI result.

AIRowsSkipped​

Number of rows that received a default value due to quota or error.

ASTFuzzerQueries​

Number of fuzzed queries attempted by the server-side AST fuzzer.

AddressesDiscovered​

Total count of new addresses in DNS resolve results for HTTP connections

AddressesExpired​

Total count of expired addresses which is no longer presented in DNS resolve results for HTTP connections

AddressesMarkedAsFailed​

Total count of addresses which have been marked as faulty due to connection errors for HTTP connections

AggregatingSortedMilliseconds​

Total time spent while aggregating sorted columns

AggregationHashTablesInitializedAsTwoLevel​

How many hash tables were inited as two-level for aggregation.

AggregationOptimizedEqualRangesOfKeys​

For how many blocks optimization of equal ranges of keys was applied

AggregationPreallocatedElementsInHashTables​

How many elements were preallocated in hash tables for aggregation.

AllUsersThrottlerBytes​

Bytes passed through 'max_network_bandwidth_for_all_users' throttler.

AllUsersThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_network_bandwidth_for_all_users' throttling.

AnalyzePatchRangesMicroseconds​

Total time spent analyzing index of patch parts

ApplyPatchesMicroseconds​

Total time spent applying patch parts to blocks

ArenaAllocBytes​

Number of bytes allocated for memory Arena (used for GROUP BY and similar operations)

ArenaAllocChunks​

Number of chunks allocated for memory Arena (used for GROUP BY and similar operations)

AsyncInsertBytes​

Data size in bytes of asynchronous INSERT queries.

AsyncInsertCacheHits​

Number of times a duplicate hash id has been found in asynchronous INSERT hash id cache.

AsyncInsertQuery​

Same as InsertQuery, but only for asynchronous INSERT queries.

AsyncInsertRows​

Number of rows inserted by asynchronous INSERT queries.

AsyncLoaderWaitMicroseconds​

Total time a query was waiting for async loader jobs.

AsyncLoggingConsoleDroppedMessages​

How many messages have been dropped from the console log due to the async log queue being full

AsyncLoggingConsoleTotalMessages​

How many messages (accepted or dropped) have been sent to the async queue for the console log

AsyncLoggingErrorFileLogDroppedMessages​

How many messages have been dropped from error file log due to the async log queue being full

AsyncLoggingErrorFileLogTotalMessages​

How many messages (accepted or dropped) have been sent to the async queue for the error file log

AsyncLoggingFileLogDroppedMessages​

How many messages have been dropped from the file log due to the async log queue being full

AsyncLoggingFileLogTotalMessages​

How many messages (accepted or dropped) have been sent to the async queue for the file log

AsyncLoggingSyslogDroppedMessages​

How many messages have been dropped from the syslog due to the async log queue being full

AsyncLoggingSyslogTotalMessages​

How many messages (accepted or dropped) have been sent to the async queue for the syslog

AsyncLoggingTextLogDroppedMessages​

How many messages have been dropped from text_log due to the async log queue being full

AsyncLoggingTextLogTotalMessages​

How many messages (accepted or dropped) have been sent to the async queue for the text_log

AsynchronousReadWaitMicroseconds​

Time spent in waiting for asynchronous reads in asynchronous local read.

AsynchronousReaderIgnoredBytes​

Number of bytes ignored during asynchronous reading

AsynchronousRemoteReadWaitMicroseconds​

Time spent in waiting for asynchronous remote reads.

AzureCommitBlockList​

Number of Azure blob storage API CommitBlockList calls

AzureCopyObject​

Number of Azure blob storage API CopyObject calls

AzureCreateContainer​

Number of Azure blob storage API CreateContainer calls.

AzureDeleteObjects​

Number of Azure blob storage API DeleteObject(s) calls.

AzureGetObject​

Number of Azure API GetObject calls.

AzureGetProperties​

Number of Azure blob storage API GetProperties calls.

AzureGetRequestThrottlerBlocked​

Number of Azure GET requests blocked by throttler.

AzureGetRequestThrottlerCount​

Number of Azure GET requests passed through throttler: blocked and not blocked.

AzureGetRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform Azure GET request throttling.

AzureListObjects​

Number of Azure blob storage API ListObjects calls.

AzurePutRequestThrottlerBlocked​

Number of Azure PUT requests blocked by throttler.

AzurePutRequestThrottlerCount​

Number of Azure PUT requests passed through throttler: blocked and not blocked.

AzurePutRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform Azure PUT request throttling.

AzureReadMicroseconds​

Total time spent waiting for Azure read requests.

AzureReadRequestsCount​

Number of Azure read requests.

AzureReadRequestsErrors​

Number of Azure read request errors.

AzureReadRequestsRedirects​

Number of Azure read request redirects.

AzureReadRequestsThrottling​

Number of Azure read requests throttled.

AzureStageBlock​

Number of Azure blob storage API StageBlock calls

AzureUpload​

Number of Azure blob storage API Upload calls

AzureWriteMicroseconds​

Total time spent waiting for Azure write requests.

AzureWriteRequestsCount​

Number of Azure write requests.

AzureWriteRequestsErrors​

Number of Azure write request errors.

AzureWriteRequestsRedirects​

Number of Azure write request redirects.

AzureWriteRequestsThrottling​

Number of Azure write requests throttled.

BackgroundLoadingMarksTasks​

Number of background tasks for loading marks

BackupEntriesCollectorForTablesDataMicroseconds​

Time spent making backup entries for tables data

BackupEntriesCollectorMicroseconds​

Time spent making backup entries

BackupEntriesCollectorRunPostTasksMicroseconds​

Time spent running post tasks after making backup entries

BackupLockFileReads​

How many times the '.lock' file was read while making backup

BackupPreparingFileInfosMicroseconds​

Time spent preparing file infos for backup entries

BackupReadLocalBytesToCalculateChecksums​

Total size of files read locally to calculate checksums for backup entries

BackupReadLocalFilesToCalculateChecksums​

Number of files read locally to calculate checksums for backup entries

BackupReadMetadataMicroseconds​

Time spent reading backup metadata from .backup file

BackupReadRemoteBytesToCalculateChecksums​

Total size of files read from remote disks to calculate checksums for backup entries

BackupReadRemoteFilesToCalculateChecksums​

Number of files read from remote disks to calculate checksums for backup entries

BackupThrottlerBytes​

Bytes passed through 'max_backup_bandwidth_for_server' throttler.

BackupThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_backup_bandwidth_for_server' throttling.

BackupWriteMetadataMicroseconds​

Time spent writing backup metadata to .backup file

BackupsOpenedForRead​

Number of backups opened for reading

BackupsOpenedForUnlock​

Number of backups opened for unlocking

BackupsOpenedForWrite​

Number of backups opened for writing

BlobCopierThreadLockBlobsErrors​

Number of blobs lock errors occurred during BlobCopier execution

BlobCopierThreadLockedBlobs​

Number of blobs returned from metadata storage

BlobCopierThreadRecordBlobsErrors​

Number of blobs recording errors occurred during BlobCopier execution

BlobCopierThreadRecordedBlobs​

Number of blobs which replication by BlobCopier was recorded in metadata storage

BlobCopierThreadReplicateBlobsErrors​

Number of blobs replication errors occurred during BlobCopier execution

BlobCopierThreadReplicatedBlobs​

Number of blobs replicated by BlobCopier

BlobCopierThreadRuns​

Number of BlobCopier thread executes

BlobKillerThreadLockBlobsErrors​

Number of blobs lock errors occurred during BlobKiller execution

BlobKillerThreadLockedBlobs​

Number of blobs returned from metadata storage

BlobKillerThreadRecordBlobsErrors​

Number of blobs recording errors occurred during BlobKiller execution

BlobKillerThreadRecordedBlobs​

Number of blobs which removal by BlobKiller was recorded in metadata storage

BlobKillerThreadRemoveBlobsErrors​

Number of blobs removal errors occurred during BlobKiller execution

BlobKillerThreadRemoveTasks​

Number of remove tasks created by BlobKiller

BlobKillerThreadRemovedBlobs​

Number of blobs removed by BlobKiller

BlobKillerThreadRuns​

Number of BlobKiller thread executes

BuildPatchesJoinMicroseconds​

Total time spent building indexes and hash tables for applying patch parts with Join mode

BuildPatchesMergeMicroseconds​

Total time spent building indexes for applying patch parts with Merge mode

CacheWarmerBytesDownloaded​

Amount of data fetched into filesystem cache by dedicated background threads.

CacheWarmerDataPartsDownloaded​

Number of data parts that were fully fetched by CacheWarmer.

CachedReadBufferCacheWriteBytes​

Bytes written from source (remote fs, etc) to filesystem cache

CachedReadBufferCacheWriteMicroseconds​

Time spent writing data into filesystem cache

CachedReadBufferCreateBufferMicroseconds​

Prepare buffer time

CachedReadBufferPredownloadedBytes​

Bytes read from filesystem cache source. Cache segments are read from left to right as a whole, it might be that we need to predownload some part of the segment irrelevant for the current task just to get to the needed data

CachedReadBufferPredownloadedFromSourceBytes​

Bytes read from filesystem cache source for predownload (from remote fs, etc)

CachedReadBufferPredownloadedFromSourceMicroseconds​

Time reading from filesystem cache source for predownload (from remote filesystem, etc)

CachedReadBufferReadFromCacheBytes​

Bytes read from filesystem cache

CachedReadBufferReadFromCacheHits​

Number of times the read from filesystem cache hit the cache.

CachedReadBufferReadFromCacheMicroseconds​

Time reading from filesystem cache

CachedReadBufferReadFromCacheMisses​

Number of times the read from filesystem cache miss the cache.

CachedReadBufferReadFromSourceBytes​

Bytes read from filesystem cache source (from remote fs, etc)

CachedReadBufferReadFromSourceMicroseconds​

Time reading from filesystem cache source (from remote filesystem, etc)

CachedReadBufferWaitReadBufferMicroseconds​

Time spend waiting for internal read buffer (includes cache waiting)

CachedWriteBufferCacheWriteBytes​

Bytes written from source (remote fs, etc) to filesystem cache

CachedWriteBufferCacheWriteMicroseconds​

Time spent writing data into filesystem cache

CannotRemoveEphemeralNode​

Number of times an error happened while trying to remove ephemeral node. This is not an issue, because our implementation of ZooKeeper library guarantee that the session will expire and the node will be removed.

CannotWriteToWriteBufferDiscard​

Number of stack traces dropped by query profiler or signal handler because pipe is full or cannot write to pipe.

CoalescingSortedMilliseconds​

Total time spent while coalescing sorted columns

CollapsingSortedMilliseconds​

Total time spent while collapsing sorted columns

CommonBackgroundExecutorTaskCancelMicroseconds​

Time spent in cancel() for Common executor tasks.

CommonBackgroundExecutorTaskExecuteStepMicroseconds​

Time spent in executeStep() for Common executor tasks.

CommonBackgroundExecutorTaskResetMicroseconds​

Time spent resetting task for Common executor.

CommonBackgroundExecutorWaitMicroseconds​

Time spent waiting for completion in Common executor.

CompileExpressionsBytes​

Number of bytes used for expressions compilation.

CompileExpressionsMicroseconds​

Total time spent for compilation of expressions to LLVM code.

CompileFunction​

Number of times a compilation of generated LLVM code (to create fused function for complex expressions) was initiated.

CompiledFunctionExecute​

Number of times a compiled function was executed.

CompressedReadBufferBlocks​

Number of compressed blocks (the blocks of data that are compressed independent of each other) read from compressed sources (files, network).

CompressedReadBufferBytes​

Number of uncompressed bytes (the number of bytes after decompression) read from compressed sources (files, network).

CompressedReadBufferChecksumDoesntMatch​

Number of times the compressed block checksum did not match.

CompressedReadBufferChecksumDoesntMatchMicroseconds​

Total time spent detecting bit-flips due to compressed block checksum mismatches.

CompressedReadBufferChecksumDoesntMatchSingleBitMismatch​

Number of times a compressed block checksum mismatch was caused by a single-bit difference.

ConcurrencyControlDownscales​

Total number of CPU downscaling events

ConcurrencyControlPreemptedMicroseconds​

Total time a query was waiting due to preemption of CPU slots.

ConcurrencyControlPreemptions​

Total number of CPU preemptions

ConcurrencyControlQueriesDelayed​

Total number of CPU slot allocations (queries) that were required to wait for slots to upscale

ConcurrencyControlSlotsAcquired​

Total number of CPU slots acquired

ConcurrencyControlSlotsAcquiredNonCompeting​

Total number of noncompeting CPU slot acquired

ConcurrencyControlSlotsDelayed​

Number of CPU slot not granted initially and required to wait for a free CPU slot

ConcurrencyControlSlotsGranted​

Number of CPU slot granted according to guarantee of 1 thread per query and for queries with setting 'use_concurrency_control' = 0

ConcurrencyControlUpscales​

Total number of CPU upscaling events

ConcurrencyControlWaitMicroseconds​

Total time a query was waiting on resource requests for CPU slots.

ConcurrentQuerySlotsAcquired​

Total number of query slots acquired

ConcurrentQueryWaitMicroseconds​

Total time a query was waiting for a query slots

ConnectionPoolIsFullMicroseconds​

Total time spent waiting for a slot in connection pool.

ContextLock​

Number of times the lock of Context was acquired or tried to acquire. This is global lock.

ContextLockWaitMicroseconds​

Context lock wait time in microseconds

CoordinatedMergesMergeAssignmentRequest​

Total number of merge assignment requests

CoordinatedMergesMergeAssignmentRequestMicroseconds​

Total time spend in merge assignment client

CoordinatedMergesMergeAssignmentResponse​

Total number of merge assignment requests

CoordinatedMergesMergeAssignmentResponseMicroseconds​

Total time spend in merge assignment handler

CoordinatedMergesMergeCoordinatorFetchMetadataMicroseconds​

Total time spend on fetching fresh metadata inside merge coordinator

CoordinatedMergesMergeCoordinatorFilterMicroseconds​

Total time spend on filtering prepared merges inside merge coordinator

CoordinatedMergesMergeCoordinatorLockStateExclusivelyCount​

Total number of exclusive captures of coordinator state lock

CoordinatedMergesMergeCoordinatorLockStateExclusivelyMicroseconds​

Total time spend on locking coordinator state mutex exclusively

CoordinatedMergesMergeCoordinatorLockStateForShareCount​

Total number of for share captures of coordinator state lock

CoordinatedMergesMergeCoordinatorLockStateForShareMicroseconds​

Total time spend on locking coordinator state mutex for share

CoordinatedMergesMergeCoordinatorSelectMergesMicroseconds​

Total time spend on finding merge using merge selectors inside merge coordinator

CoordinatedMergesMergeCoordinatorUpdateCount​

Total number of merge coordinator updates

CoordinatedMergesMergeCoordinatorUpdateMicroseconds​

Total time spend on updating merge coordinator state

CoordinatedMergesMergeWorkerUpdateCount​

Total number merge worker updates

CoordinatedMergesMergeWorkerUpdateMicroseconds​

Total time spend on updating local state of assigned merges on worker

CreatedLogEntryForMerge​

Successfully created log entry to merge parts in ReplicatedMergeTree.

CreatedLogEntryForMutation​

Successfully created log entry to mutate parts in ReplicatedMergeTree.

CreatedReadBufferDirectIO​

Number of times a read buffer with O_DIRECT was created for reading data (while choosing among other read methods).

CreatedReadBufferDirectIOFailed​

Number of times a read buffer with O_DIRECT was attempted to be created for reading data (while choosing among other read methods), but the OS did not allow it (due to lack of filesystem support or other reasons) and we fallen back to the ordinary reading method.

CreatedReadBufferMMap​

Number of times a read buffer using 'mmap' was created for reading data (while choosing among other read methods).

CreatedReadBufferMMapFailed​

Number of times a read buffer with 'mmap' was attempted to be created for reading data (while choosing among other read methods), but the OS did not allow it (due to lack of filesystem support or other reasons) and we fallen back to the ordinary reading method.

CreatedReadBufferOrdinary​

Number of times ordinary read buffer was created for reading data (while choosing among other read methods).

DNSError​

Total count of errors in DNS resolution

DataAfterMergeDiffersFromReplica​

Number of times data after merge is not byte-identical to the data on another replicas. There could be several reasons:

  1. Using newer version of compression library after server update.
  2. Using another compression method.
  3. Non-deterministic compression algorithm (highly unlikely).
  4. Non-deterministic merge algorithm due to logical error in code.
  5. Data corruption in memory due to bug in code.
  6. Data corruption in memory due to hardware issue.
  7. Manual modification of source data after server startup.
  8. Manual modification of checksums stored in ZooKeeper.
  9. Part format related settings like 'enable_mixed_granularity_parts' are different on different replicas. The server successfully detected this situation and will download merged part from the replica to force the byte-identical result.

DataAfterMutationDiffersFromReplica​

Number of times data after mutation is not byte-identical to the data on other replicas. In addition to the reasons described in 'DataAfterMergeDiffersFromReplica', it is also possible due to non-deterministic mutation.

DefaultImplementationForNullsRows​

Number of rows processed by default implementation for nulls in function execution

DefaultImplementationForNullsRowsWithNulls​

Number of rows which contain null values processed by default implementation for nulls in function execution

DelayedInserts​

Number of times the INSERT of a block to a MergeTree table was throttled due to high number of active data parts for partition.

DelayedInsertsMilliseconds​

Total number of milliseconds spent while the INSERT of a block to a MergeTree table was throttled due to high number of active data parts for partition.

DelayedMutations​

Number of times the mutation of a MergeTree table was throttled due to high number of unfinished mutations for table.

DelayedMutationsMilliseconds​

Total number of milliseconds spent while the mutation of a MergeTree table was throttled due to high number of unfinished mutations for table.

DeltaLakePartitionPrunedFiles​

Number of skipped files during DeltaLake partition pruning

DeltaLakeScannedFiles​

Number of files scanned during DeltaLake scan callbacks

DeltaLakeSnapshotInitializations​

Number of times a DeltaLake table snapshot was initialized (loaded from object storage)

DictCacheKeysExpired​

Number of keys looked up in the dictionaries of 'cache' types and found in the cache but they were obsolete.

DictCacheKeysHit​

Number of keys looked up in the dictionaries of 'cache' types and found in the cache.

DictCacheKeysNotFound​

Number of keys looked up in the dictionaries of 'cache' types and not found.

DictCacheKeysRequested​

Number of keys requested from the data source for the dictionaries of 'cache' types.

DictCacheKeysRequestedFound​

Number of keys requested from the data source for dictionaries of 'cache' types and found in the data source.

DictCacheKeysRequestedMiss​

Number of keys requested from the data source for dictionaries of 'cache' types but not found in the data source.

DictCacheLockReadNs​

Number of nanoseconds spend in waiting for read lock to lookup the data for the dictionaries of 'cache' types.

DictCacheLockWriteNs​

Number of nanoseconds spend in waiting for write lock to update the data for the dictionaries of 'cache' types.

DictCacheRequestTimeNs​

Number of nanoseconds spend in querying the external data sources for the dictionaries of 'cache' types.

DictCacheRequests​

Number of bulk requests to the external data sources for the dictionaries of 'cache' types.

DirectorySync​

Number of times the F_FULLFSYNC/fsync/fdatasync function was called for directories.

DirectorySyncElapsedMicroseconds​

Total time spent waiting for F_FULLFSYNC/fsync/fdatasync syscall for directories.

DiskAzureCommitBlockList​

Number of Disk Azure blob storage API CommitBlockList calls

DiskAzureCopyObject​

Number of Disk Azure blob storage API CopyObject calls

DiskAzureCreateContainer​

Number of Disk Azure blob storage API CreateContainer calls.

DiskAzureDeleteObjects​

Number of Azure blob storage API DeleteObject(s) calls.

DiskAzureGetObject​

Number of Disk Azure API GetObject calls.

DiskAzureGetProperties​

Number of Disk Azure blob storage API GetProperties calls.

DiskAzureGetRequestThrottlerBlocked​

Number of Azure disk GET requests blocked by throttler.

DiskAzureGetRequestThrottlerCount​

Number of Azure disk GET requests passed through throttler: blocked and not blocked.

DiskAzureGetRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform Azure disk GET request throttling.

DiskAzureListObjects​

Number of Disk Azure blob storage API ListObjects calls.

DiskAzurePutRequestThrottlerBlocked​

Number of Azure disk PUT requests blocked by throttler.

DiskAzurePutRequestThrottlerCount​

Number of Azure disk PUT requests passed through throttler: blocked and not blocked.

DiskAzurePutRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform Azure disk PUT request throttling.

DiskAzureReadMicroseconds​

Total time spent waiting for Azure disk read requests.

DiskAzureReadRequestsCount​

Number of Azure disk read requests.

DiskAzureReadRequestsErrors​

Number of Azure disk read request errors.

DiskAzureReadRequestsRedirects​

Number of Azure disk read request redirects.

DiskAzureReadRequestsThrottling​

Number of Azure disk read requests throttled.

DiskAzureStageBlock​

Number of Disk Azure blob storage API StageBlock calls

DiskAzureUpload​

Number of Disk Azure blob storage API Upload calls

DiskAzureWriteMicroseconds​

Total time spent waiting for Azure disk write requests.

DiskAzureWriteRequestsCount​

Number of Azure disk write requests.

DiskAzureWriteRequestsErrors​

Number of Azure disk write request errors.

DiskAzureWriteRequestsRedirects​

Number of Azure disk write request redirects.

DiskAzureWriteRequestsThrottling​

Number of Azure disk write requests throttled.

DiskConnectionsCreated​

Number of created connections for disk

DiskConnectionsElapsedMicroseconds​

Total time spend on creating connections for disk

DiskConnectionsErrors​

Number of cases when creation of a connection for disk is failed

DiskConnectionsExpired​

Number of expired connections for disk

DiskConnectionsPreserved​

Number of preserved connections for disk

DiskConnectionsReset​

Number of reset connections for disk

DiskConnectionsReused​

Number of reused connections for disk

DiskObjectStorageWaitBlobRemovalMicroseconds​

Time spent waiting for pending blob removal after committing metadata transaction

DiskPlainRewritableAzureDirectoryCreated​

Number of directories created by the 'plain_rewritable' metadata storage for AzureObjectStorage.

DiskPlainRewritableAzureDirectoryRemoved​

Number of directories removed by the 'plain_rewritable' metadata storage for AzureObjectStorage.

DiskPlainRewritableLegacyLayoutDiskCount​

Number of the 'plain_rewritable' disks with legacy layout.

DiskPlainRewritableLocalDirectoryCreated​

Number of directories created by the 'plain_rewritable' metadata storage for LocalObjectStorage.

DiskPlainRewritableLocalDirectoryRemoved​

Number of directories removed by the 'plain_rewritable' metadata storage for LocalObjectStorage.

DiskPlainRewritableS3DirectoryCreated​

Number of directories created by the 'plain_rewritable' metadata storage for S3ObjectStorage.

DiskPlainRewritableS3DirectoryRemoved​

Number of directories removed by the 'plain_rewritable' metadata storage for S3ObjectStorage.

DiskReadElapsedMicroseconds​

Total time spent waiting for read syscall. This include reads from page cache.

DiskS3AbortMultipartUpload​

Number of DiskS3 API AbortMultipartUpload calls.

DiskS3CompleteMultipartUpload​

Number of DiskS3 API CompleteMultipartUpload calls.

DiskS3CopyObject​

Number of DiskS3 API CopyObject calls.

DiskS3CreateMultipartUpload​

Number of DiskS3 API CreateMultipartUpload calls.

DiskS3DeleteObjects​

Number of DiskS3 API DeleteObject(s) calls.

DiskS3GetObject​

Number of DiskS3 API GetObject calls.

DiskS3GetObjectTagging​

Number of DiskS3 API GetObjectTagging calls.

DiskS3GetRequestThrottlerBlocked​

Number of DiskS3 GET and SELECT requests blocked by throttler.

DiskS3GetRequestThrottlerCount​

Number of DiskS3 GET and SELECT requests passed through throttler: blocked and not blocked.

DiskS3GetRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform DiskS3 GET and SELECT request throttling.

DiskS3HeadObject​

Number of DiskS3 API HeadObject calls.

DiskS3ListObjects​

Number of DiskS3 API ListObjects calls.

DiskS3PutObject​

Number of DiskS3 API PutObject calls.

DiskS3PutRequestThrottlerBlocked​

Number of DiskS3 PUT, COPY, POST and LIST requests blocked by throttler.

DiskS3PutRequestThrottlerCount​

Number of DiskS3 PUT, COPY, POST and LIST requests passed through throttler: blocked and not blocked.

DiskS3PutRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform DiskS3 PUT, COPY, POST and LIST request throttling.

DiskS3ReadMicroseconds​

Time of GET and HEAD requests to DiskS3 storage.

DiskS3ReadRequestAttempts​

Number of attempts for GET and HEAD requests to DiskS3 storage, including the initial try and any retries, but excluding retries performed internally by the S3 retry strategy

DiskS3ReadRequestRetryableErrors​

Number of retryable errors for GET and HEAD requests to DiskS3 storage, excluding retries performed internally by the S3 retry strategy

DiskS3ReadRequestsCount​

Number of GET and HEAD requests to DiskS3 storage.

DiskS3ReadRequestsErrors​

Number of non-throttling errors in GET and HEAD requests to DiskS3 storage.

DiskS3ReadRequestsRedirects​

Number of redirects in GET and HEAD requests to DiskS3 storage.

DiskS3ReadRequestsThrottling​

Number of 429 and 503 errors in GET and HEAD requests to DiskS3 storage.

DiskS3UploadPart​

Number of DiskS3 API UploadPart calls.

DiskS3UploadPartCopy​

Number of DiskS3 API UploadPartCopy calls.

DiskS3WriteMicroseconds​

Time of POST, DELETE, PUT and PATCH requests to DiskS3 storage.

DiskS3WriteRequestAttempts​

Number of attempts for POST, DELETE, PUT and PATCH requests to DiskS3 storage, including the initial try and any retries, but excluding retries performed internally by the retry strategy

DiskS3WriteRequestRetryableErrors​

Number of retryable errors for POST, DELETE, PUT and PATCH requests to DiskS3 storage, excluding retries performed internally by the retry strategy

DiskS3WriteRequestsCount​

Number of POST, DELETE, PUT and PATCH requests to DiskS3 storage.

DiskS3WriteRequestsErrors​

Number of non-throttling errors in POST, DELETE, PUT and PATCH requests to DiskS3 storage.

DiskS3WriteRequestsRedirects​

Number of redirects in POST, DELETE, PUT and PATCH requests to DiskS3 storage.

DiskS3WriteRequestsThrottling​

Number of 429 and 503 errors in POST, DELETE, PUT and PATCH requests to DiskS3 storage.

DiskWriteElapsedMicroseconds​

Total time spent waiting for write syscall. This include writes to page cache.

DistrCacheConnectAttempts​

Distributed Cache connection event. The number of connection attempts to distributed cache

DistrCacheConnectMicroseconds​

Distributed Cache connection event. The time spent to connect to distributed cache

DistrCacheFallbackReadMicroseconds​

Distributed Cache read buffer event. Time spend reading from fallback buffer instead of distributed cache

DistrCacheGetClientMicroseconds​

Distributed Cache connection event. Time spent getting client for distributed cache

DistrCacheGetResponseMicroseconds​

Distributed Cache client event. Time spend to wait for response from distributed cache

DistrCacheHashRingRebuilds​

Distributed Cache registry event. Number of distributed cache hash ring rebuilds

DistrCacheLockRegistryMicroseconds​

Distributed Cache registry event. Time spent to take DistributedCacheRegistry lock

DistrCacheMakeRequestErrors​

Distributed Cache client event. Number of distributed cache errors when making a request

DistrCacheNextImplMicroseconds​

Distributed Cache read buffer event. Time spend in ReadBufferFromDistributedCache::nextImpl

DistrCacheObjectStorageWriteBytes​

Distributed Cache write buffer event. Number of bytes written to object storage

DistrCacheObjectStorageWriteMicroseconds​

Distributed Cache write buffer event. Time spent writing to object storage

DistrCacheOpenedConnections​

Distributed Cache connection event. The number of open connections to distributed cache

DistrCacheOpenedConnectionsBypassingPool​

Distributed Cache connection event. The number of open connections to distributed cache bypassing pool

DistrCachePrecomputeRangesMicroseconds​

Distributed Cache read buffer event. Time spent to precompute read ranges

DistrCacheRangeChange​

Distributed Cache read buffer event. Number of times we changed read range because of seek/last_position change

DistrCacheRangeResetBackward​

Distributed Cache read buffer event. Number of times we reset read range because of seek/last_position change

DistrCacheRangeResetForward​

Distributed Cache read buffer event. Number of times we reset read range because of seek/last_position change

DistrCacheReadBytesFromFallbackBuffer​

Distributed Cache read buffer event. Bytes read from fallback buffer

DistrCacheReadErrors​

Distributed Cache read buffer event. Number of distributed cache errors during read

DistrCacheReadMicroseconds​

Distributed Cache read buffer event. Time spent reading from distributed cache

DistrCacheReadThrottlerBytes​

Bytes passed through 'max_distributed_cache_read_bandwidth_for_server' throttler.

DistrCacheReadThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_distributed_cache_read_bandwidth_for_server' throttling.

DistrCacheReceiveResponseErrors​

Distributed Cache client event. Number of distributed cache errors when receiving response a request

DistrCacheReceivedCredentialsRefreshPackets​

Distributed Cache client event. Total number of received RefreshCredentials packets received from distributed cache

DistrCacheReceivedDataPackets​

Distributed Cache client event. Total number of received data packets received from distributed cache

DistrCacheReceivedDataPacketsBytes​

Distributed Cache client event. The number of bytes in Data packets received from distributed cache

DistrCacheReceivedErrorPackets​

Distributed Cache client event. Total number of received Error packets received from distributed cache

DistrCacheReceivedOkPackets​

Distributed Cache client event. Total number of received Ok packets received from distributed cache

DistrCacheReceivedStopPackets​

Distributed Cache client event. Total number of received Stop packets received from distributed cache

DistrCacheReconnectsAfterTimeout​

Distributed Cache read buffer event. The number of reconnects after timeout

DistrCacheRegistryUpdateMicroseconds​

Distributed Cache registry event. Time spent updating distributed cache registry

DistrCacheRegistryUpdates​

Distributed Cache registry event. Number of distributed cache registry updates

DistrCacheRemoveOutdatedMicroseconds​

Distributed Cache connection event. The time spent removing outdated connections from the pool

DistrCacheReusedConnections​

Distributed Cache connection event. The number of reused connections to distributed cache

DistrCacheSentDataPackets​

Distributed Cache client event. Total number of data packets sent to distributed cache

DistrCacheSentDataPacketsBytes​

Distributed Cache client event. The number of bytes in Data packets sent to distributed cache

DistrCacheServerAckRequestPackets​

Distributed Cache server event. Number of AckRequest packets in DistributedCacheServer

DistrCacheServerCachedReadBufferCacheHits​

Distributed Cache server event. The number of times distributed cache hit the cache while reading from filesystem cache

DistrCacheServerCachedReadBufferCacheMisses​

Distributed Cache server event. The number of times distributed cache missed the cache while reading from filesystem cache

DistrCacheServerCachedReadBufferCachePredownloadBytes​

Distributed Cache server event. The number of bytes read from object storage for predownload in distributed cache while reading from filesystem cache

DistrCacheServerCachedReadBufferCacheReadBytes​

Distributed Cache server event. The number of bytes read from cache in distributed cache while reading from filesystem cache

DistrCacheServerCachedReadBufferCacheWrittenBytes​

Distributed Cache server event. The number of bytes written to cache in distributed cache while reading from filesystem cache

DistrCacheServerCachedReadBufferObjectStorageReadBytes​

Distributed Cache server event. The number of bytes read from object storage in distributed cache while reading from filesystem cache

DistrCacheServerContinueRequestPackets​

Distributed Cache server event. Number of ContinueRequest packets in DistributedCacheServer

DistrCacheServerCredentialsRefresh​

Distributed Cache server event. The number of expired credentials were refreshed

DistrCacheServerEndRequestPackets​

Distributed Cache server event. Number of EndRequest packets in DistributedCacheServer

DistrCacheServerNewS3CachedClients​

Distributed Cache server event. The number of new cached s3 clients

DistrCacheServerProcessRequestMicroseconds​

Distributed Cache server event. Time spent processing request on DistributedCache server side

DistrCacheServerReceivedCredentialsRefreshPackets​

Distributed Cache server event. Number of RefreshCredentials client packets in DistributedCacheServer

DistrCacheServerReusedS3CachedClients​

Distributed Cache server event. The number of reused cached s3 clients

DistrCacheServerSkipped​

Distributed Cache server event. The number of times distributed cache server was skipped because of previous failed connection attempts

DistrCacheServerStartRequestPackets​

Distributed Cache server event. Number of StartRequest packets in DistributedCacheServer

DistrCacheServerSwitches​

Distributed Cache read buffer event. Number of server switches between distributed cache servers in read/write-through cache

DistrCacheServerUpdates​

Distributed Cache event. The number of server switches during read or write because the hash-chosen server changed (e.g. due to server deregistration)

DistrCacheStaleReconnections​

Distributed Cache connection event. The number of reconnections due to stale (peer-closed) pooled connections

DistrCacheStartRangeMicroseconds​

Distributed Cache read buffer event. Time spent to start a new read range with distributed cache

DistrCacheSuccessfulConnectAttempts​

Distributed Cache connection event. The number of successful connection attempts to distributed cache

DistrCacheSuccessfulRegistryUpdates​

Distributed Cache registry event. The number of successful server registry updates

DistrCacheTemporaryFilesBytesWritten​

Distributed Cache connection event. Number of bytes written to temporary files created in distributed cache

DistrCacheTemporaryFilesCreated​

Distributed Cache connection event. Number of temporary files created in distributed cache

DistrCacheUnsuccessfulConnectAttempts​

Distributed Cache connection event. The number of unsuccessful connection attempts to distributed cache

DistrCacheUnsuccessfulRegistryUpdates​

Distributed Cache registry event. The number of unsuccessful server registry updates

DistrCacheUnusedDataPacketsBytes​

Distributed Cache client event. The number of bytes in Data packets which were ignored

DistrCacheUnusedPackets​

Distributed Cache client event. Number of skipped unused packets from distributed cache

DistrCacheUnusedPacketsBufferAllocations​

Distributed Cache client event. The number of extra buffer allocations in case we could not reuse existing buffer

DistrCacheWriteBytes​

Distributed Cache write buffer event. Number of bytes written to distributed cache

DistrCacheWriteErrors​

Distributed Cache write buffer event. Number of distributed cache errors during write

DistrCacheWriteMicroseconds​

Distributed Cache write buffer event. Time spent in WriteBufferFromDistributedCache::writeToFileSegment

DistrCacheWriteReconnectsAfterTimeout​

Distributed Cache write buffer event. The number of reconnects after timeout

DistrCacheWriteThrottlerBytes​

Bytes passed through 'max_distributed_cache_write_bandwidth_for_server' throttler.

DistrCacheWriteThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_distributed_cache_write_bandwidth_for_server' throttling.

DistributedAsyncInsertionFailures​

Number of failures for asynchronous insertion into a Distributed table (with 'distributed_foreground_insert' = 0)

DistributedConnectionConnectCount​

Number of connects to other servers done during distributed query execution. Happens when new connection is established instead of using existing from pool.

DistributedConnectionFailAtAll​

Total count when distributed connection fails after all retries finished.

DistributedConnectionFailTry​

Total count when distributed connection fails with retry.

DistributedConnectionMissingTable​

Number of times we rejected a replica from a distributed query, because it did not contain a table needed for the query.

DistributedConnectionReconnectCount​

Number of reconnects to other servers done during distributed query execution. It can happen when a stale connection has been acquired from connection pool

DistributedConnectionSkipReadOnlyReplica​

Number of replicas skipped during INSERT into Distributed table due to replicas being read-only

DistributedConnectionStaleReplica​

Number of times we rejected a replica from a distributed query, because some table needed for a query had replication lag higher than the configured threshold.

DistributedConnectionTries​

Total count of distributed connection attempts.

DistributedConnectionUsable​

Total count of successful distributed connections to a usable server (with required table, but maybe stale).

DistributedDelayedInserts​

Number of times the INSERT of a block to a Distributed table was throttled due to high number of pending bytes.

DistributedDelayedInsertsMilliseconds​

Total number of milliseconds spent while the INSERT of a block to a Distributed table was throttled due to high number of pending bytes.

DistributedIndexAnalysisMicroseconds​

Total time spent during distributed index analysis

DistributedIndexAnalysisMissingParts​

Number of missing parts during distributed index analysis that will be resolved locally

DistributedIndexAnalysisParts​

Number of parts send for distributed index analysis

DistributedIndexAnalysisReplicaFallback​

Number of times distributed index analysis failed on one of replicas with fallback to local replica

DistributedIndexAnalysisReplicaUnavailable​

Number of times distributed index analysis failed on one of replicas without fallback (failed during connect)

DistributedIndexAnalysisScheduledReplicas​

Number of replicas (local replica will be accounted once) to which distributed index analysis has been scheduled

DistributedRejectedInserts​

Number of times the INSERT of a block to a Distributed table was rejected with 'Too many bytes' exception due to high number of pending bytes.

DistributedSyncInsertionTimeoutExceeded​

A timeout has exceeded while waiting for shards during synchronous insertion into a Distributed table (with 'distributed_foreground_insert' = 1)

DuplicatedAsyncInserts​

Number of async inserts in the INSERTed block to a ReplicatedMergeTree table was deduplicated.

DuplicatedInsertedBlocks​

Number of the synchronous inserts to a *MergeTree table was deduplicated.

DuplicationElapsedMicroseconds​

Total time spent checking for duplication of INSERTed blocks to *MergeTree tables.

EngineFileLikeReadFiles​

Number of files read in table engines working with files (like File/S3/URL/HDFS).

ExecutableUserDefinedFunctionElapsedMicroseconds​

Wall clock time spent executing executable and executable pool user-defined functions, in microseconds.

ExecutableUserDefinedFunctionInputBytes​

Total bytes written to the stdin of executable and executable pool user-defined function child processes.

ExecutableUserDefinedFunctionInvocations​

Number of executable and executable pool user-defined function invocations.

ExecutableUserDefinedFunctionOutputBytes​

Total bytes read from the stdout of executable and executable pool user-defined function child processes.

ExecutableUserDefinedFunctionPeakMemoryByteSeconds​

Per-process peak memory used by executable and executable pool user-defined function child processes integrated over wall clock time, in byte-seconds.

ExecutableUserDefinedFunctionSystemTimeMicroseconds​

Kernel mode CPU time consumed by executable and executable pool user-defined function child processes, in microseconds.

ExecutableUserDefinedFunctionUserTimeMicroseconds​

User mode CPU time consumed by executable and executable pool user-defined function child processes, in microseconds.

ExecuteShellCommand​

Number of shell command executions.

ExternalAggregationCompressedBytes​

Number of bytes written to disk for aggregation in external memory.

ExternalAggregationMerge​

Number of times temporary files were merged for aggregation in external memory.

ExternalAggregationUncompressedBytes​

Amount of data (uncompressed, before compression) written to disk for aggregation in external memory.

ExternalAggregationWritePart​

Number of times a temporary file was written to disk for aggregation in external memory.

ExternalDataSourceLocalCacheReadBytes​

Bytes read from local cache buffer in RemoteReadBufferCache

ExternalJoinCompressedBytes​

Number of compressed bytes written for JOIN in external memory.

ExternalJoinMerge​

Number of times temporary files were merged for JOIN in external memory.

ExternalJoinUncompressedBytes​

Amount of data (uncompressed, before compression) written for JOIN in external memory.

ExternalJoinWritePart​

Number of times a temporary file was written to disk for JOIN in external memory.

ExternalProcessingCompressedBytesTotal​

Number of compressed bytes written by external processing (sorting/aggregating/joining)

ExternalProcessingFilesTotal​

Number of files used by external processing (sorting/aggregating/joining)

ExternalProcessingUncompressedBytesTotal​

Amount of data (uncompressed, before compression) written by external processing (sorting/aggregating/joining)

ExternalSortCompressedBytes​

Number of compressed bytes written for sorting in external memory.

ExternalSortMerge​

Number of times temporary files were merged for sorting in external memory.

ExternalSortUncompressedBytes​

Amount of data (uncompressed, before compression) written for sorting in external memory.

ExternalSortWritePart​

Number of times a temporary file was written to disk for sorting in external memory.

FailedAsyncInsertQuery​

Number of failed ASYNC INSERT queries.

FailedInitialQuery​

Number of failed initial queries.

FailedInitialSelectQuery​

Same as FailedInitialQuery, but only for SELECT queries.

FailedInsertQuery​

Same as FailedQuery, but only for INSERT queries.

FailedInternalInsertQuery​

Same as FailedInternalQuery, but only for INSERT queries.

FailedInternalQuery​

Number of failed internal queries.

FailedInternalSelectQuery​

Same as FailedInternalQuery, but only for SELECT queries.

FailedQuery​

Number of total failed queries, both internal and user queries.

FailedSelectQuery​

Same as FailedQuery, but only for SELECT queries.

FetchBackgroundExecutorTaskCancelMicroseconds​

Time spent in cancel() for Fetch executor tasks.

FetchBackgroundExecutorTaskExecuteStepMicroseconds​

Time spent in executeStep() for Fetch executor tasks.

FetchBackgroundExecutorTaskResetMicroseconds​

Time spent resetting task for Fetch executor.

FetchBackgroundExecutorWaitMicroseconds​

Time spent waiting for completion in Fetch executor.

FileOpen​

Number of files opened.

FileSegmentCompleteMicroseconds​

Duration of FileSegment::complete() in filesystem cache

FileSegmentFailToIncreasePriority​

Number of times the priority was not increased due to a high contention on the cache lock

FileSegmentHolderCompleteMicroseconds​

File segments holder complete() time

FileSegmentIncreasePriorityMicroseconds​

File segment increase priority time

FileSegmentLockMicroseconds​

Lock file segment time

FileSegmentRemoveMicroseconds​

File segment remove() time

FileSegmentWaitMicroseconds​

Wait on DOWNLOADING state

FileSegmentWriteMicroseconds​

File segment write() time

FileSync​

Number of times the F_FULLFSYNC/fsync/fdatasync function was called for files.

FileSyncElapsedMicroseconds​

Total time spent waiting for F_FULLFSYNC/fsync/fdatasync syscall for files.

FilesystemCacheBackgroundDownloadQueuePush​

Number of file segments sent for background download in filesystem cache

FilesystemCacheBackgroundEvictedBytes​

Number of bytes evicted by background thread

FilesystemCacheBackgroundEvictedFileSegments​

Number of file segments evicted by background thread

FilesystemCacheCheckCorrectness​

Number of times FileCache::assertCacheCorrectness was called

FilesystemCacheCheckCorrectnessMicroseconds​

How much time does FileCache::assertCacheCorrectness takes

FilesystemCacheCreatedKeyDirectories​

Number of created key directories

FilesystemCacheEvictMicroseconds​

Filesystem cache eviction time

FilesystemCacheEvictedBytes​

Number of bytes evicted from filesystem cache

FilesystemCacheEvictedFileSegments​

Number of file segments evicted from filesystem cache

FilesystemCacheEvictedFileSegmentsDuringPriorityIncrease​

Number of file segments evicted from filesystem cache when increasing priority of file segments (Applies to SLRU cache policy)

FilesystemCacheEvictionReusedIterator​

Number of filesystem cache iterator reusing

FilesystemCacheEvictionSkippedEvictingFileSegments​

Number of file segments skipped for eviction because of being in evicting state

FilesystemCacheEvictionSkippedFileSegments​

Number of file segments skipped for eviction because of being in unreleasable state

FilesystemCacheEvictionSkippedMovingFileSegments​

Number of file segments skipped for eviction because of being in moving state

FilesystemCacheEvictionTries​

Number of filesystem cache eviction attempts

FilesystemCacheFailToReserveSpaceBecauseOfCacheResize​

Number of times space reservation was skipped due to the cache is being resized

FilesystemCacheFailToReserveSpaceBecauseOfLockContention​

Number of times space reservation was skipped due to a high contention on the cache lock

FilesystemCacheFailedEvictionCandidates​

Number of file segments which unexpectedly failed to be evicted during dynamic filesystem cache eviction

FilesystemCacheFailedReserveAttempts​

Number of failed file cache space reservation attempts.

FilesystemCacheFreeSpaceKeepingThreadRun​

Number of times background thread executed free space keeping job

FilesystemCacheFreeSpaceKeepingThreadWorkMilliseconds​

Time for which background thread executed free space keeping job

FilesystemCacheGetMicroseconds​

Filesystem cache get() time

FilesystemCacheGetOrSetMicroseconds​

Filesystem cache getOrSet() time

FilesystemCacheHoldFileSegments​

Filesystem cache file segments count, which were hold

FilesystemCacheLoadMetadataMicroseconds​

Time spent loading filesystem cache metadata

FilesystemCacheLockKeyMicroseconds​

Lock cache key time

FilesystemCacheLockMetadataMicroseconds​

Lock filesystem cache metadata time

FilesystemCachePriorityReadLockMicroseconds​

Lock filesystem cache time for read in priority queue

FilesystemCachePriorityWriteLockMicroseconds​

Lock filesystem cache time for write to priority queue

FilesystemCacheReserveAttempts​

Filesystem cache space reservation attempt

FilesystemCacheReserveMicroseconds​

Filesystem cache space reservation time

FilesystemCacheStateLockMicroseconds​

Lock filesystem cache time for state lock

FilesystemCacheUnusedHoldFileSegments​

Filesystem cache file segments count, which were hold, but not used (because of seek or LIMIT n, etc)

FilterPartsByVirtualColumnsMicroseconds​

Total time spent in filterPartsByVirtualColumns function.

FilterTransformPassedBytes​

Number of bytes that passed the filter in the query

FilterTransformPassedRows​

Number of rows that passed the filter in the query

FilteringMarksWithPrimaryKeyMicroseconds​

Time spent filtering parts by PK.

FilteringMarksWithPrimaryKeyProcessedMarks​

Total marks processed during PK analysis.

FilteringMarksWithSecondaryKeysMicroseconds​

Time spent filtering parts by skip indexes.

FunctionExecute​

Number of SQL ordinary function calls (SQL functions are called on per-block basis, so this number represents the number of blocks).

GatheredColumns​

Number of columns gathered during the vertical stage of merges.

GatheringColumnMilliseconds​

Total time spent while gathering columns for vertical merge

GlobalThreadPoolExpansions​

Counts the total number of times new threads have been added to the global thread pool. This metric indicates the frequency of expansions in the global thread pool to accommodate increased processing demands.

GlobalThreadPoolJobWaitTimeMicroseconds​

Measures the elapsed time from when a job is scheduled in the thread pool to when it is picked up for execution by a worker thread. This metric helps identify delays in job processing, indicating the responsiveness of the thread pool to new tasks.

GlobalThreadPoolJobs​

Counts the number of jobs that have been pushed to the global thread pool.

GlobalThreadPoolLockWaitMicroseconds​

Total time threads have spent waiting for locks in the global thread pool.

GlobalThreadPoolShrinks​

Counts the total number of times the global thread pool has shrunk by removing threads. This occurs when the number of idle threads exceeds max_thread_pool_free_size, indicating adjustments in the global thread pool size in response to decreased thread utilization.

GlobalThreadPoolThreadCreationMicroseconds​

Total time spent waiting for new threads to start.

HTTPConnectionsCreated​

Number of created client HTTP connections

HTTPConnectionsElapsedMicroseconds​

Total time spend on creating client HTTP connections

HTTPConnectionsErrors​

Number of cases when creation of a client HTTP connection failed

HTTPConnectionsExpired​

Number of expired client HTTP connections

HTTPConnectionsPreserved​

Number of preserved client HTTP connections

HTTPConnectionsReset​

Number of reset client HTTP connections

HTTPConnectionsReused​

Number of reused client HTTP connections

HTTPServerConnectionsClosed​

Number of closed server HTTP connections. Keep alive has not been negotiated

HTTPServerConnectionsCreated​

Number of created server HTTP connections

HTTPServerConnectionsExpired​

Number of expired server HTTP connections.

HTTPServerConnectionsPreserved​

Number of preserved server HTTP connections. Connection kept alive successfully

HTTPServerConnectionsReset​

Number of reset server HTTP connections. Server closes connection

HTTPServerConnectionsReused​

Number of reused server HTTP connections

HardPageFaults​

The number of hard page faults in query execution threads. High values indicate either that you forgot to turn off swap on your server, or eviction of memory pages of the ClickHouse binary during very high memory pressure, or successful usage of the 'mmap' read method for the tables data.

HashJoinPreallocatedElementsInHashTables​

How many elements were preallocated in hash tables for hash join.

HedgedRequestsChangeReplica​

Total count when timeout for changing replica expired in hedged requests.

IOBufferAllocBytes​

Number of bytes allocated for IO buffers (for ReadBuffer/WriteBuffer).

IOBufferAllocs​

Number of allocations of IO buffers (for ReadBuffer/WriteBuffer).

IOUringCQEsCompleted​

Total number of successfully completed io_uring CQEs

IOUringCQEsFailed​

Total number of completed io_uring CQEs with failures

IOUringSQEsResubmitsAsync​

Total number of asynchronous io_uring SQE resubmits performed

IOUringSQEsResubmitsSync​

Total number of synchronous io_uring SQE resubmits performed

IOUringSQEsSubmitted​

Total number of io_uring SQEs submitted

IcebergIteratorInitializationMicroseconds​

Total time spent on synchronous initialization of iceberg data iterators.

IcebergMetadataFilesCacheHits​

Number of times iceberg metadata files have been found in the cache.

IcebergMetadataFilesCacheMisses​

Number of times iceberg metadata files have not been found in the iceberg metadata cache and had to be read from (remote) disk.

IcebergMetadataFilesCacheStaleMisses​

Number of times iceberg metadata files have been found in the cache, but were considered stale and had to be read from (remote) disk.

IcebergMetadataFilesCacheWeightLost​

Approximate number of bytes evicted from the iceberg metadata cache.

IcebergMetadataReadWaitTimeMicroseconds​

Total time data readers spend waiting for iceberg metadata files to be read and parsed, summed across all reader threads.

IcebergMetadataReturnedObjectInfos​

Total number of returned object infos from iceberg iterator.

IcebergMetadataUpdateMicroseconds​

Total time spent on synchronous initialization of iceberg data iterators.

IcebergMinMaxIndexPrunedFiles​

Number of skipped files by using MinMax index in Iceberg

IcebergMinMaxNonPrunedDeleteFiles​

Total number of accepted data files-position delete file pairs by minmax analysis from pairs suitable by partitioning and sequence number.

IcebergMinMaxPrunedDeleteFiles​

Total number of accepted data files-position delete file pairs by minmax analysis from pairs suitable by partitioning and sequence number.

IcebergPartitionPrunedFiles​

Number of skipped files during Iceberg partition pruning

IcebergTrivialCountOptimizationApplied​

Trivial count optimization applied while reading from Iceberg

IcebergVersionHintUsed​

Number of times version-hint.text has been used.

IgnoredColdParts​

See setting ignore_cold_parts_seconds. Number of times read queries ignored very new parts that weren't pulled into cache by CacheWarmer yet.

IndexAnalysisRounds​

Number of times index analysis was performed within the query.

IndexBinarySearchAlgorithm​

Number of times the binary search algorithm is used over the index marks

IndexGenericExclusionSearchAlgorithm​

Number of times the generic exclusion search algorithm is used over the index marks

InitialQuery​

Same as Query, but only counts initial queries (see is_initial_query).

InitialSelectQuery​

Same as InitialQuery, but only for SELECT queries.

InsertQueriesWithSubqueries​

Count INSERT queries with all subqueries

InsertQuery​

Same as Query, but only for INSERT queries.

InsertQueryTimeMicroseconds​

Total time of INSERT queries.

InsertedBytes​

Number of bytes (uncompressed; for columns as they stored in memory) INSERTed to all tables.

InsertedCompactParts​

Number of parts inserted in Compact format.

InsertedRows​

Number of rows INSERTed to all tables.

InsertedWideParts​

Number of parts inserted in Wide format.

InterfaceHTTPReceiveBytes​

Number of bytes received through HTTP interfaces

InterfaceHTTPSendBytes​

Number of bytes sent through HTTP interfaces

InterfaceInterserverReceiveBytes​

Number of bytes received through interserver interfaces

InterfaceInterserverSendBytes​

Number of bytes sent through interserver interfaces

InterfaceMySQLReceiveBytes​

Number of bytes received through MySQL interfaces

InterfaceMySQLSendBytes​

Number of bytes sent through MySQL interfaces

InterfaceNativeReceiveBytes​

Number of bytes received through native interfaces

InterfaceNativeSendBytes​

Number of bytes sent through native interfaces

InterfacePostgreSQLReceiveBytes​

Number of bytes received through PostgreSQL interfaces

InterfacePostgreSQLSendBytes​

Number of bytes sent through PostgreSQL interfaces

InterfacePrometheusReceiveBytes​

Number of bytes received through Prometheus interfaces

InterfacePrometheusSendBytes​

Number of bytes sent through Prometheus interfaces

JemallocFailedAllocationSampleTracking​

Total number of times tracking of jemalloc allocation sample failed

JemallocFailedDeallocationSampleTracking​

Total number of times tracking of jemalloc deallocation sample failed

JoinBuildPostProcessingMicroseconds​

Elapsed time of post-processing steps after building the right JOIN side.

JoinBuildTableRowCount​

Total number of rows in the build table for a JOIN operation.

JoinDelayedJoinedTransformBlockCount​

Number of blocks emitted by DelayedJoinedBlocksWorkerTransform.

JoinDelayedJoinedTransformRowCount​

Number of rows emitted by DelayedJoinedBlocksWorkerTransform.

JoinNonJoinedTransformBlockCount​

Number of blocks emitted by NonJoinedBlocksTransform.

JoinNonJoinedTransformRowCount​

Number of non-joined rows emitted by NonJoinedBlocksTransform.

JoinOptimizeMicroseconds​

Total time spent executing JOIN plan optimizations.

JoinProbeTableRowCount​

Total number of rows in the probe table for a JOIN operation.

JoinReorderMicroseconds​

Total time spent executing JOIN reordering algorithm.

JoinResultRowCount​

Total number of rows in the result of a JOIN operation.

JoinSpillingHashJoinSwitchedToGraceJoin​

Number of times a (Concurrent)HashJoin was switched to GraceHashJoin due to memory limit in SpillingHashJoin.

KafkaBackgroundReads​

Number of background reads populating materialized views from Kafka since server start

KafkaCommitFailures​

Number of failed commits of consumed offsets to Kafka (usually is a sign of some data duplication)

KafkaCommits​

Number of successful commits of consumed offsets to Kafka (normally should be the same as KafkaBackgroundReads)

KafkaConsumerErrors​

Number of errors reported by librdkafka during polls

KafkaDirectReads​

Number of direct selects from Kafka tables since server start

KafkaMVNotReady​

Number of failed attempts to stream data to a materialized view that is not ready

KafkaMessagesFailed​

Number of Kafka messages ClickHouse failed to parse

KafkaMessagesPolled​

Number of Kafka messages polled from librdkafka to ClickHouse

KafkaMessagesProduced​

Number of messages produced to Kafka

KafkaMessagesRead​

Number of Kafka messages already processed by ClickHouse

KafkaProducerErrors​

Number of errors during producing the messages to Kafka

KafkaProducerFlushes​

Number of explicit flushes to Kafka producer

KafkaRebalanceAssignments​

Number of partition assignments (the final stage of consumer group rebalance)

KafkaRebalanceErrors​

Number of failed consumer group rebalances

KafkaRebalanceRevocations​

Number of partition revocations (the first stage of consumer group rebalance)

KafkaRowsRead​

Number of rows parsed from Kafka messages

KafkaRowsRejected​

Number of parsed rows which were later rejected (due to rebalances / errors or similar reasons). Those rows will be consumed again after the rebalance.

KafkaRowsWritten​

Number of rows inserted into Kafka tables

KafkaWrites​

Number of writes (inserts) to Kafka tables

KeeperAddWatchRequest​

Number of add watches requests

KeeperBatchMaxCount​

Number of batches that hit max_requests_batch_size limit

KeeperBatchMaxReadCount​

Number of batches that hit max_read_batch_size limit

KeeperBatchMaxReadTotalSize​

Number of batches that hit max_read_batch_bytes_size limit

KeeperBatchMaxTotalSize​

Number of batches that hit max_requests_batch_bytes_size limit

KeeperChangelogFileSyncMicroseconds​

Time spent in fsync for Keeper changelog (uncompressed logs only)

KeeperChangelogLockWaitMicroseconds​

Time spent waiting for acquiring Keeper changelog lock

KeeperChangelogWrittenBytes​

Number of bytes written to the changelog in Keeper

KeeperCheckRequest​

Number of check requests

KeeperCheckWatchRequest​

Number of remove watches requests

KeeperCommitWaitElapsedMicroseconds​

Time spent waiting for certain log to be committed

KeeperCommits​

Number of successful commits

KeeperCommitsFailed​

Number of failed commits

KeeperCreateRequest​

Number of create requests

KeeperExistsRequest​

Number of exists requests

KeeperGetRequest​

Number of get requests

KeeperLatency​

Keeper latency

KeeperListRecursiveRequest​

Number of get children recursive requests

KeeperListRequest​

Number of list requests

KeeperLiveSessionsLockWaitMicroseconds​

Time spent waiting to acquire Keeper live sessions lock

KeeperLogsEntryReadFromCommitCache​

Number of log entries in Keeper being read from commit logs cache

KeeperLogsEntryReadFromFile​

Number of log entries in Keeper being read directly from the changelog file

KeeperLogsEntryReadFromLatestCache​

Number of log entries in Keeper being read from latest logs cache

KeeperLogsPrefetchedEntries​

Number of log entries in Keeper being prefetched from the changelog file

KeeperMultiReadRequest​

Number of multi read requests

KeeperMultiRequest​

Number of multi requests

KeeperPacketsReceived​

Packets received by keeper server

KeeperPacketsSent​

Packets sent by keeper server

KeeperPreprocessElapsedMicroseconds​

Keeper preprocessing latency for a single request

KeeperProcessAndResponsesLockWaitMicroseconds​

Time spent waiting for acquiring Keeper process and responses lock

KeeperProcessElapsedMicroseconds​

Keeper commit latency for a single request

KeeperReadBatchCount​

Number of read request batches processed by Keeper

KeeperReadBatchTotalRequests​

Total number of read requests processed in batches by Keeper

KeeperReadRequestQueueLockWaitMicroseconds​

Time spent waiting for acquiring Keeper read request queue lock

KeeperReadSnapshot​

Number of completed snapshot reads

KeeperReadSnapshotDeferred​

Number of snapshot reads deferred because the requested snapshot is no longer available locally; NuRaft will retry the latest snapshot.

KeeperReadSnapshotFailed​

Number of failed snapshot reads

KeeperReadSnapshotObject​

Number of snapshot objects sent to followers

KeeperReconfigRequest​

Number of reconfig requests

KeeperRemoveRequest​

Number of remove requests

KeeperRemoveWatchRequest​

Number of remove watches requests

KeeperRequestRejectedDueToSoftMemoryLimitCount​

Number requests that have been rejected due to soft memory limit exceeded

KeeperRequestTotal​

Total requests number on keeper server

KeeperRequestTotalWithSubrequests​

Total requests number on keeper server, counting each subrequest within a multi request

KeeperSaveSnapshot​

Number of snapshot save

KeeperSaveSnapshotFailed​

Number of failed snapshot saves

KeeperSaveSnapshotObject​

Number of snapshot objects received from leader

KeeperServerWriteLockWaitMicroseconds​

Time spent waiting for acquiring Keeper server write lock

KeeperSessionCallbackLockWaitMicroseconds​

Time spent waiting for acquiring Keeper session callback lock

KeeperSetRequest​

Number of set requests

KeeperSetWatchesRequest​

Number of set watches requests

KeeperSnapshotApplys​

Number of snapshot applying

KeeperSnapshotApplysFailed​

Number of failed snapshot applying

KeeperSnapshotCreations​

Number of snapshots creations

KeeperSnapshotCreationsFailed​

Number of failed snapshot creations

KeeperSnapshotFileSyncMicroseconds​

Time spent in fsync for Keeper snapshot files

KeeperSnapshotRemoteLoaderErrors​

Number of remote read errors in RemoteSnapshotLoader while serving a snapshot to a follower

KeeperSnapshotWrittenBytes​

Number of bytes written to snapshot files in Keeper

KeeperStaleRequestsSkipped​

Number of Keeper requests skipped because the session is no longer live

KeeperStorageLockWaitMicroseconds​

Time spent waiting for acquiring Keeper storage lock

KeeperStorageSharedLockWaitMicroseconds​

Time spent waiting for acquiring Keeper storage shared lock

KeeperTotalElapsedMicroseconds​

Keeper total latency for a single request

KeeperWriteBatchCount​

Number of write request batches processed by Keeper

KeeperWriteBatchTotalRequests​

Total number of write requests processed in batches by Keeper

LoadedDataParts​

Number of data parts loaded by MergeTree tables during initialization.

LoadedDataPartsMicroseconds​

Microseconds spent by MergeTree tables for loading data parts during initialization.

LoadedMarksCount​

Number of marks loaded (total across columns).

LoadedMarksFiles​

Number of mark files loaded.

LoadedMarksMemoryBytes​

Size of in-memory representations of loaded marks.

LoadedPrimaryIndexBytes​

Number of rows of primary key loaded.

LoadedPrimaryIndexFiles​

Number of primary index files loaded.

LoadedPrimaryIndexRows​

Number of rows of primary key loaded.

LoadedStatisticsMicroseconds​

Elapsed time of loading statistics from parts

LoadingMarksTasksCanceled​

Number of times background tasks for loading marks were canceled

LocalReadThrottlerBytes​

Bytes passed through 'max_local_read_bandwidth_for_server'/'max_local_read_bandwidth' throttler.

LocalReadThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_local_read_bandwidth_for_server'/'max_local_read_bandwidth' throttling.

LocalThreadPoolBusyMicroseconds​

Total time threads have spent executing the actual work.

LocalThreadPoolExpansions​

Counts the total number of times threads have been borrowed from the global thread pool to expand local thread pools.

LocalThreadPoolJobWaitTimeMicroseconds​

Measures the elapsed time from when a job is scheduled in the thread pool to when it is picked up for execution by a worker thread. This metric helps identify delays in job processing, indicating the responsiveness of the thread pool to new tasks.

LocalThreadPoolJobs​

Counts the number of jobs that have been pushed to the local thread pools.

LocalThreadPoolLockWaitMicroseconds​

Total time threads have spent waiting for locks in the local thread pools.

LocalThreadPoolShrinks​

Counts the total number of times threads have been returned to the global thread pool from local thread pools.

LocalThreadPoolThreadCreationMicroseconds​

Total time local thread pools have spent waiting to borrow a thread from the global pool.

LocalWriteThrottlerBytes​

Bytes passed through 'max_local_write_bandwidth_for_server'/'max_local_write_bandwidth' throttler.

LocalWriteThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_local_write_bandwidth_for_server'/'max_local_write_bandwidth' throttling.

LogDebug​

Number of log messages with level Debug

LogError​

Number of log messages with level Error

LogFatal​

Number of log messages with level Fatal

LogInfo​

Number of log messages with level Info

LogTest​

Number of log messages with level Test

LogTrace​

Number of log messages with level Trace

LogWarning​

Number of log messages with level Warning

LoggerElapsedNanoseconds​

Cumulative time spend in logging

MMappedFileCacheHits​

Number of times a file has been found in the MMap cache (for the 'mmap' read_method), so we didn't have to mmap it again.

MMappedFileCacheMisses​

Number of times a file has not been found in the MMap cache (for the 'mmap' read_method), so we had to mmap it again.

MainConfigLoads​

Number of times the main configuration was reloaded.

MarkCacheEvictedBytes​

Number of bytes evicted from the mark cache.

MarkCacheEvictedFiles​

Number of mark files evicted from the mark cache.

MarkCacheEvictedMarks​

Number of marks evicted from the mark cache.

MarkCacheHits​

Number of times an entry has been found in the mark cache, so we didn't have to load a mark file.

MarkCacheMisses​

Number of times an entry has not been found in the mark cache, so we had to load a mark file in memory, which is a costly operation, adding to query latency.

MarksTasksFromCache​

Number of times marks were loaded synchronously because they were already present in the cache.

MemoryAllocatedWithoutCheck​

Number of times memory has been allocated without checking for memory constraints.

MemoryAllocatedWithoutCheckBytes​

Amount of bytes that has been allocated without checking for memory constraints.

MemoryAllocatorPurge​

Total number of times memory allocator purge was requested

MemoryAllocatorPurgeTimeMicroseconds​

Total time spent for memory allocator purge

MemoryOvercommitWaitTimeMicroseconds​

Total time spent in waiting for memory to be freed in OvercommitTracker.

MemoryWorkerRun​

Number of runs done by MemoryWorker in background

MemoryWorkerRunElapsedMicroseconds​

Total time spent by MemoryWorker for background work

Merge​

Number of launched background merges.

MergeCommitMilliseconds​

Total time spent for committing merge results (part renaming, checksum verification, ZooKeeper updates)

MergeExecuteMilliseconds​

Total busy time spent for execution of background merges

MergeHorizontalStageExecuteMilliseconds​

Total busy time spent for execution of horizontal stage of background merges

MergeHorizontalStageTotalMilliseconds​

Total time spent for horizontal stage of background merges

MergeMutateBackgroundExecutorTaskCancelMicroseconds​

Time spent in cancel() for MergeMutate executor tasks.

MergeMutateBackgroundExecutorTaskExecuteStepMicroseconds​

Time spent in executeStep() for MergeMutate executor tasks.

MergeMutateBackgroundExecutorTaskResetMicroseconds​

Time spent resetting task for MergeMutate executor.

MergeMutateBackgroundExecutorWaitMicroseconds​

Time spent waiting for completion in MergeMutate executor.

MergePrewarmStageExecuteMilliseconds​

Total busy time spent for execution of prewarm stage of background merges

MergePrewarmStageTotalMilliseconds​

Total time spent for prewarm stage of background merges

MergeProjectionStageExecuteMilliseconds​

Total busy time spent for execution of projection stage of background merges

MergeProjectionStageTotalMilliseconds​

Total time spent for projection stage of background merges

MergeSourceParts​

Number of source parts scheduled for merges.

MergeTextIndexStageExecuteMilliseconds​

Total busy time spent for execution of text index stage of background merges

MergeTextIndexStageTotalMilliseconds​

Total time spent for text index stage of background merges

MergeTotalMilliseconds​

Total time spent for background merges

MergeTreeAllRangesAnnouncementsSent​

The number of announcements sent from the remote server to the initiator server about the set of data parts (for MergeTree tables). Measured on the remote server side.

MergeTreeAllRangesAnnouncementsSentElapsedMicroseconds​

Time spent in sending the announcement from the remote server to the initiator server about the set of data parts (for MergeTree tables). Measured on the remote server side.

MergeTreeDataProjectionWriterBlocks​

Number of blocks INSERTed to MergeTree tables projection. Each block forms a data part of level zero.

MergeTreeDataProjectionWriterBlocksAlreadySorted​

Number of blocks INSERTed to MergeTree tables projection that appeared to be already sorted.

MergeTreeDataProjectionWriterCompressedBytes​

Bytes written to filesystem for data INSERTed to MergeTree tables projection.

MergeTreeDataProjectionWriterMergingBlocksMicroseconds​

Time spent merging blocks

MergeTreeDataProjectionWriterRows​

Number of rows INSERTed to MergeTree tables projection.

MergeTreeDataProjectionWriterSortingBlocksMicroseconds​

Time spent sorting blocks (for projection it might be a key different from table's sorting key)

MergeTreeDataProjectionWriterUncompressedBytes​

Uncompressed bytes (for columns as they stored in memory) INSERTed to MergeTree tables projection.

MergeTreeDataWriterBlocks​

Number of blocks INSERTed to MergeTree tables. Each block forms a data part of level zero.

MergeTreeDataWriterBlocksAlreadySorted​

Number of blocks INSERTed to MergeTree tables that appeared to be already sorted.

MergeTreeDataWriterCompressedBytes​

Bytes written to filesystem for data INSERTed to MergeTree tables.

MergeTreeDataWriterMergingBlocksMicroseconds​

Time spent merging input blocks (for special MergeTree engines)

MergeTreeDataWriterProjectionsCalculationMicroseconds​

Time spent calculating projections

MergeTreeDataWriterRows​

Number of rows INSERTed to MergeTree tables.

MergeTreeDataWriterSkipIndicesCalculationMicroseconds​

Time spent calculating skip indices

MergeTreeDataWriterSortingBlocksMicroseconds​

Time spent sorting blocks

MergeTreeDataWriterStatisticsCalculationMicroseconds​

Time spent calculating statistics

MergeTreeDataWriterUncompressedBytes​

Uncompressed bytes (for columns as they stored in memory) INSERTed to MergeTree tables.

MergeTreePrefetchedReadPoolInit​

Time spent preparing tasks in MergeTreePrefetchedReadPool

MergeTreeReadTaskRequestsReceived​

The number of callbacks requested from the remote server back to the initiator server to choose the read task (for MergeTree tables). Measured on the initiator server side.

MergeTreeReadTaskRequestsSent​

The number of callbacks requested from the remote server back to the initiator server to choose the read task (for MergeTree tables). Measured on the remote server side.

MergeTreeReadTaskRequestsSentElapsedMicroseconds​

Time spent in callbacks requested from the remote server back to the initiator server to choose the read task (for MergeTree tables). Measured on the remote server side.

MergeVerticalStageExecuteMilliseconds​

Total busy time spent for execution of vertical stage of background merges

MergeVerticalStageTotalMilliseconds​

Total time spent for vertical stage of background merges

MergeWrittenRows​

Number of rows written during the merge.

MergedColumns​

Number of columns merged during the horizontal stage of merges.

MergedIntoCompactParts​

Number of parts merged into Compact format.

MergedIntoWideParts​

Number of parts merged into Wide format.

MergedProjections​

Number of projections merged (not rebuilt) during MergeTree merges.

MergedRows​

Rows read for background merges. This is the number of rows before merge.

MergedUncompressedBytes​

Uncompressed bytes (for columns as they stored in memory) that was read for background merges. This is the number before merge.

MergerMutatorPartsInRangesForMergeCount​

Amount of candidate parts for merge

MergerMutatorPrepareRangesForMergeElapsedMicroseconds​

Time spent to prepare parts ranges which can be merged according to merge predicate.

MergerMutatorRangesForMergeCount​

Amount of candidate ranges for merge

MergerMutatorSelectPartsForMergeElapsedMicroseconds​

Time spent to select parts from ranges which can be merged.

MergerMutatorSelectRangePartsCount​

Amount of parts in selected range for merge

MergerMutatorsGetPartsForMergeElapsedMicroseconds​

Time spent to take data parts snapshot to build ranges from them.

MergesRejectedByMemoryLimit​

Number of background merges rejected due to memory limit

MergesThrottlerBytes​

Bytes passed through 'max_merges_bandwidth_for_server' throttler.

MergesThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_merges_bandwidth_for_server' throttling.

MergingSortedMilliseconds​

Total time spent while merging sorted columns

MetadataFromKeeperBackgroundCleanupBlobs​

Number of times an empty blob layout part was cleaned up by background task

MetadataFromKeeperBackgroundCleanupErrors​

Number of times an error was encountered in background cleanup task

MetadataFromKeeperBackgroundCleanupObjects​

Number of times a old deleted object clean up was performed by background task

MetadataFromKeeperBackgroundCleanupTransactions​

Number of times old transaction idempotency token was cleaned up by background task

MetadataFromKeeperCacheHit​

Number of times an object storage metadata request was answered from cache without making request to Keeper

MetadataFromKeeperCacheMiss​

Number of times an object storage metadata request had to be answered from Keeper

MetadataFromKeeperCacheTooManyInvalidated​

Number of times filesystem cache returned too many invalidated entries

MetadataFromKeeperCacheUpdateMicroseconds​

Total time spent in updating the cache including waiting for responses from Keeper

MetadataFromKeeperCleanupTransactionCommit​

Number of times metadata transaction commit for deleted objects cleanup was attempted

MetadataFromKeeperCleanupTransactionCommitRetry​

Number of times metadata transaction commit for deleted objects cleanup was retried

MetadataFromKeeperIndividualOperations​

Number of paths read or written by single or multi requests to Keeper

MetadataFromKeeperIndividualOperationsMicroseconds​

Time spend during single or multi requests to Keeper

MetadataFromKeeperOperations​

Number of times a request was made to Keeper

MetadataFromKeeperReconnects​

Number of times a reconnect to Keeper was done

MetadataFromKeeperTransactionCommit​

Number of times metadata transaction commit was attempted

MetadataFromKeeperTransactionCommitRetry​

Number of times metadata transaction commit was retried

MetadataFromKeeperUpdateCacheOneLevel​

Number of times a cache update for one level of directory tree was done

MoveBackgroundExecutorTaskCancelMicroseconds​

Time spent in cancel() for Move executor tasks.

MoveBackgroundExecutorTaskExecuteStepMicroseconds​

Time spent in executeStep() for Move executor tasks.

MoveBackgroundExecutorTaskResetMicroseconds​

Time spent resetting task for Move executor.

MoveBackgroundExecutorWaitMicroseconds​

Time spent waiting for completion in Move executor.

MutateTaskProjectionsCalculationMicroseconds​

Time spent calculating projections in mutations

MutatedRows​

Rows read for mutations. This is the number of rows before mutation

MutatedUncompressedBytes​

Uncompressed bytes (for columns as they stored in memory) that was read for mutations. This is the number before mutation.

MutationAffectedRowsUpperBound​

The upper bound of number of rows that were affected by mutation (e.g. number of rows that satisfy the predicate of UPDATE or DELETE mutation). The actual number may be slightly less

MutationAllPartColumns​

Number of times when task to mutate all columns in part was created

MutationCommitMilliseconds​

Total time spent for committing mutation results (part renaming, checksum verification, ZooKeeper updates)

MutationCreatedEmptyParts​

Number of total parts which were replaced to empty parts instead of running mutation

MutationExecuteMilliseconds​

Total busy time spent for execution of mutations.

MutationSomePartColumns​

Number of times when task to mutate some columns in part was created

MutationTotalMilliseconds​

Total time spent for mutations.

MutationTotalParts​

Number of total parts for which mutations tried to be applied

MutationUntouchedParts​

Number of total parts for which mutations tried to be applied but which was completely skipped according to predicate

MutationsAppliedOnFlyInAllReadTasks​

Total number of applied mutations on-fly among all read tasks

MutationsThrottlerBytes​

Bytes passed through 'max_mutations_bandwidth_for_server' throttler.

MutationsThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_mutations_bandwidth_for_server' throttling.

NaiveBayesClassifierModelsAllocatedBytes​

Number of bytes allocated for Naive Bayes Classifier models.

NaiveBayesClassifierModelsLoaded​

Number of Naive Bayes Classifier models loaded.

NetworkReceiveBytes​

Total number of bytes received from network. Only ClickHouse-related network interaction is included, not by 3rd party libraries.

NetworkReceiveElapsedMicroseconds​

Total time spent waiting for data to receive or receiving data from network. Only ClickHouse-related network interaction is included, not by 3rd party libraries.

NetworkSendBytes​

Total number of bytes send to network. Only ClickHouse-related network interaction is included, not by 3rd party libraries.

NetworkSendElapsedMicroseconds​

Total time spent waiting for data to send to network or sending data to network. Only ClickHouse-related network interaction is included, not by 3rd party libraries.

NotCreatedLogEntryForMerge​

Log entry to merge parts in ReplicatedMergeTree is not created due to concurrent log update by another replica.

NotCreatedLogEntryForMutation​

Log entry to mutate parts in ReplicatedMergeTree is not created due to concurrent log update by another replica.

OSCPUVirtualTimeMicroseconds​

CPU time spent seen by OS. Does not include involuntary waits due to virtualization.

OSCPUWaitMicroseconds​

Total time a thread was ready for execution but waiting to be scheduled by OS, from the OS point of view.

OSIOWaitMicroseconds​

Total time a thread spent waiting for a result of IO operation, from the OS point of view. This is real IO that doesn't include page cache.

OSReadBytes​

Number of bytes read from disks or block devices. Doesn't include bytes read from page cache. May include excessive data due to block size, readahead, etc.

OSReadChars​

Number of bytes read from filesystem, including page cache, as well as network and other files.

OSWriteBytes​

Number of bytes written to disks or block devices. Doesn't include bytes that are in page cache dirty pages. May not include data that was written by OS asynchronously.

OSWriteChars​

Number of bytes written to filesystem, including page cache, as well as network and other files.

ObjectStorageGlobFilteredObjects​

Objects that did not match the glob or regex pattern and were skipped during listing.

ObjectStorageListedObjects​

Total objects returned by object storage listing API before any filtering.

ObjectStoragePredicateFilteredObjects​

Objects removed by virtual column predicate filtering on _path/_file.

ObjectStorageQueueCancelledFiles​

Number cancelled files in StorageS3(Azure)Queue

ObjectStorageQueueCleanupMaxSetSizeOrTTLMicroseconds​

Time spent to set file as failed

ObjectStorageQueueCommitRequests​

Number of keeper requests to commit files as either failed or processed

ObjectStorageQueueExceptionsDuringInsert​

Number of exceptions during insert in S3(Azure)Queue

ObjectStorageQueueExceptionsDuringRead​

Number of exceptions during read in S3(Azure)Queue

ObjectStorageQueueFailedFiles​

Number of files which failed to be processed

ObjectStorageQueueFailedToBatchSetProcessing​

Number of times batched set processing request failed

ObjectStorageQueueFilteredFiles​

Number of filtered files in StorageS3(Azure)Queue

ObjectStorageQueueInsertIterations​

Number of insert iterations

ObjectStorageQueueListedFiles​

Number of listed files in StorageS3(Azure)Queue

ObjectStorageQueueMovedObjects​

Number of objects moved as part of after_processing = move

ObjectStorageQueueProcessedFiles​

Number of files which were processed

ObjectStorageQueueProcessedRows​

Number of processed rows in StorageS3(Azure)Queue

ObjectStorageQueuePullMicroseconds​

Time spent to read file data

ObjectStorageQueueReadBytes​

Number of read bytes (not equal to the number of actually inserted bytes)

ObjectStorageQueueReadFiles​

Number of read files (not equal to the number of actually inserted files)

ObjectStorageQueueReadRows​

Number of read rows (not equal to the number of actually inserted rows)

ObjectStorageQueueRemovedObjects​

Number of objects removed as part of after_processing = delete

ObjectStorageQueueSuccessfulCommits​

Number of successful keeper commits

ObjectStorageQueueTaggedObjects​

Number of objects tagged as part of after_processing = tag

ObjectStorageQueueTrySetProcessingFailed​

The number of times we unsuccessfully set file as processing

ObjectStorageQueueTrySetProcessingRequests​

The number of times we tried to make set processing request

ObjectStorageQueueTrySetProcessingSucceeded​

The number of times we successfully set file as processing

ObjectStorageQueueUnsuccessfulCommits​

Number of unsuccessful keeper commits

ObjectStorageReadObjects​

Objects actually opened for reading by the object storage source.

ObsoleteReplicatedParts​

Number of times a data part was covered by another data part that has been fetched from a replica (so, we have marked a covered data part as obsolete and no longer needed).

OpenedFileCacheHits​

Number of times a file has been found in the opened file cache, so we didn't have to open it again.

OpenedFileCacheMicroseconds​

Amount of time spent executing OpenedFileCache methods.

OpenedFileCacheMisses​

Number of times a file has been found in the opened file cache, so we had to open it again.

OtherQueryTimeMicroseconds​

Total time of queries that are not SELECT or INSERT.

OverflowAny​

Number of times approximate GROUP BY was in effect: when aggregation was performed only on top of first 'max_rows_to_group_by' unique keys and other keys were ignored due to 'group_by_overflow_mode' = 'any'.

OverflowBreak​

Number of times, data processing was cancelled by query complexity limitation with setting '*_overflow_mode' = 'break' and the result is incomplete.

OverflowThrow​

Number of times, data processing was cancelled by query complexity limitation with setting '*_overflow_mode' = 'throw' and exception was thrown.

PageCacheHits​

Number of times a block of data has been found in the userspace page cache.

PageCacheMisses​

Number of times a block of data has not been found in the userspace page cache.

PageCacheOvercommitResize​

Number of times the userspace page cache was auto-resized to free memory during a memory allocation.

PageCacheReadBytes​

Number of bytes read from userspace page cache.

PageCacheResized​

Number of times the userspace page cache was auto-resized (typically happens a few times per second, controlled by memory_worker_period_ms).

PageCacheWeightLost​

Number of bytes evicted from the userspace page cache

ParallelReplicasAnnouncementMicroseconds​

Time spent to send an announcement

ParallelReplicasAvailableCount​

Number of replicas available to execute a query with task-based parallel replicas

ParallelReplicasCollectingOwnedSegmentsMicroseconds​

Time spent collecting segments meant by hash

ParallelReplicasDeniedRequests​

Number of completely denied requests to the initiator

ParallelReplicasHandleAnnouncementMicroseconds​

Time spent processing replicas announcements

ParallelReplicasHandleRequestMicroseconds​

Time spent processing requests for marks from replicas

ParallelReplicasNumRequests​

Number of requests to the initiator.

ParallelReplicasProcessingPartsMicroseconds​

Time spent processing data parts

ParallelReplicasQueryCount​

Number of (sub)queries executed using parallel replicas during a query execution

ParallelReplicasReadAssignedForStealingMarks​

Sum across all replicas of how many of scheduled marks were assigned for stealing by consistent hash

ParallelReplicasReadAssignedMarks​

Sum across all replicas of how many of scheduled marks were assigned by consistent hash

ParallelReplicasReadMarks​

How many marks were read by the given replica

ParallelReplicasReadRequestMicroseconds​

Time spent for read requests

ParallelReplicasReadUnassignedMarks​

Sum across all replicas of how many unassigned marks were scheduled

ParallelReplicasStealingByHashMicroseconds​

Time spent collecting segments meant for stealing by hash

ParallelReplicasStealingLeftoversMicroseconds​

Time spent collecting orphaned segments

ParallelReplicasUnavailableCount​

Number of replicas which was chosen, but found to be unavailable during query execution with task-based parallel replicas

ParallelReplicasUsedCount​

Number of replicas used to execute a query with task-based parallel replicas

ParquetColumnsFilterExpression​

The total number of columns that were passed through filter

ParquetDecodingTaskBatches​

Task groups sent to a thread pool by parquet reader

ParquetDecodingTasks​

Tasks issued by parquet reader

ParquetFetchWaitTimeMicroseconds​

Time of waiting for parquet file reads from decoding threads (not prefetching threads)

ParquetMetadataCacheHits​

Number of times parquet metadata has been found in the cache.

ParquetMetadataCacheMisses​

Number of times parquet metadata has not been found in the cache and had to be read from disk.

ParquetMetadataCacheWeightLost​

Approximate number of bytes evicted from the parquet metadata cache.

ParquetPrefetcherReadEntireFile​

The total number of read with ReadMode::EntireFileIsInMemory by DB::Parquet::Prefetcher

ParquetPrefetcherReadRandomRead​

The total number of reads with ReadMode::RandomRead by DB::Parquet::Prefetcher

ParquetPrefetcherReadSeekAndRead​

The total number of reads with ReadMode::SeekAndRead by DB::Parquet::Prefetcher

ParquetPrunedRowGroups​

The total number of row groups pruned from parquet data

ParquetReadRowGroups​

The total number of row groups read from parquet data

ParquetRowsFilterExpression​

The total number of rows that were passed through filter

PartsLockHoldMicroseconds​

Total time spent holding data parts lock in MergeTree tables

PartsLockWaitMicroseconds​

Total time spent waiting for data parts lock in MergeTree tables

PartsLocks​

Number of times data parts lock has been acquired for MergeTree tables

PatchesAcquireLockMicroseconds​

Total number of microseconds spent to acquire lock for executing lightweight updates

PatchesAcquireLockTries​

Total number of tries to acquire lock for executing lightweight updates

PatchesAppliedInAllReadTasks​

Total number of applied patch parts among all read tasks

PatchesJoinAppliedInAllReadTasks​

Total number of applied patch parts with Join mode among all read tasks

PatchesJoinRowsAddedToHashTable​

Total number of rows added to hash tables when applying patch parts with Join mode

PatchesMergeAppliedInAllReadTasks​

Total number of applied patch parts with Merge mode among all read tasks

PatchesReadRows​

Total number of rows read from patch parts

PatchesReadUncompressedBytes​

Total number of uncompressed bytes read from patch parts

PerfAlignmentFaults​

Number of alignment faults. These happen when unaligned memory accesses happen; the kernel can handle these but it reduces performance. This happens only on some architectures (never on x86).

PerfBranchInstructions​

Retired branch instructions. Prior to Linux 2.6.35, this used the wrong event on AMD processors.

PerfBranchMisses​

Mispredicted branch instructions.

PerfBusCycles​

Bus cycles, which can be different from total cycles.

PerfCPUClock​

The CPU clock, a high-resolution per-CPU timer

PerfCPUCycles​

Total cycles. Be wary of what happens during CPU frequency scaling.

PerfCPUMigrations​

Number of times the process has migrated to a new CPU

PerfCacheMisses​

Cache misses. Usually this indicates Last Level Cache misses; this is intended to be used in conjunction with the PERFCOUNTHWCACHEREFERENCES event to calculate cache miss rates.

PerfCacheReferences​

Cache accesses. Usually, this indicates Last Level Cache accesses, but this may vary depending on your CPU. This may include prefetches and coherency messages; again this depends on the design of your CPU.

PerfContextSwitches​

Number of context switches

PerfDataTLBMisses​

Data TLB misses

PerfDataTLBReferences​

Data TLB references

PerfEmulationFaults​

Number of emulation faults. The kernel sometimes traps on unimplemented instructions and emulates them for user space. This can negatively impact performance.

PerfInstructionTLBMisses​

Instruction TLB misses

PerfInstructionTLBReferences​

Instruction TLB references

PerfInstructions​

Retired instructions. Be careful, these can be affected by various issues, most notably hardware interrupt counts.

PerfLocalMemoryMisses​

Local NUMA node memory read misses

PerfLocalMemoryReferences​

Local NUMA node memory reads

PerfMinEnabledRunningTime​

Running time for event with minimum enabled time. Used to track the amount of event multiplexing

PerfMinEnabledTime​

For all events, minimum time that an event was enabled. Used to track event multiplexing influence

PerfRefCPUCycles​

Total cycles; not affected by CPU frequency scaling.

PerfStalledCyclesBackend​

Stalled cycles during retirement.

PerfStalledCyclesFrontend​

Stalled cycles during issue.

PerfTaskClock​

A clock count specific to the task that is running

PolygonsAddedToPool​

A polygon has been added to the cache (pool) for the 'pointInPolygon' function.

PolygonsInPoolAllocatedBytes​

The number of bytes for polygons added to the cache (pool) for the 'pointInPolygon' function.

PreferredWarmedUnmergedParts​

See setting prefer_warmed_unmerged_parts_seconds. Number of times read queries used outdated pre-merge parts that are in cache instead of merged part that wasn't pulled into cache by CacheWarmer yet.

PrimaryIndexCacheHits​

Number of times an entry has been found in the primary index cache, so we didn't have to load a index file.

PrimaryIndexCacheMisses​

Number of times an entry has not been found in the primary index cache, so we had to load a index file in memory, which is a costly operation, adding to query latency.

QueriesWithSubqueries​

Count queries with all subqueries

Query​

Number of queries to be interpreted and potentially executed. Does not include queries that failed to parse or were rejected due to AST size limits, quota limits or limits on the number of simultaneously running queries. May include internal queries initiated by ClickHouse itself. Does not count subqueries.

QueryBackupThrottlerBytes​

Bytes passed through 'max_backup_bandwidth' throttler.

QueryBackupThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_backup_bandwidth' throttling.

QueryCacheAgeSeconds​

The sum of ages of found query cache entries in seconds. The value is set both for hits and misses.

QueryCacheHits​

Number of times a query result has been found in the query cache (and query computation was avoided). Only updated for SELECT queries with SETTING use_query_cache = 1.

QueryCacheMisses​

Number of times a query result has not been found in the query cache (and required query computation). Only updated for SELECT queries with SETTING use_query_cache = 1.

QueryCacheReadBytes​

The number of (uncompressed) bytes read from the query cache.

QueryCacheReadRows​

The number of rows read from the query cache.

QueryCacheWrittenBytes​

The number of (uncompressed) bytes saved into the query cache

QueryCacheWrittenRows​

The number of rows saved into the query cache.

QueryConditionCacheHits​

Number of times an entry has been found in the query condition cache (and reading of marks can be skipped). Only updated for SELECT queries with SETTING use_query_condition_cache = 1.

QueryConditionCacheMisses​

Number of times an entry has not been found in the query condition cache (and reading of mark cannot be skipped). Only updated for SELECT queries with SETTING use_query_condition_cache = 1.

QueryLocalReadThrottlerBytes​

Bytes passed through 'max_local_read_bandwidth' throttler.

QueryLocalReadThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_local_read_bandwidth' throttling.

QueryLocalWriteThrottlerBytes​

Bytes passed through 'max_local_write_bandwidth' throttler.

QueryLocalWriteThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_local_write_bandwidth' throttling.

QueryMaskingRulesMatch​

Number of times query masking rules was successfully matched.

QueryMemoryLimitExceeded​

Number of times when memory limit exceeded for query.

QueryPlanOptimizeMicroseconds​

Total time spent executing query plan optimizations.

QueryPreempted​

How many times tasks are paused and waiting due to 'priority' setting

QueryProfilerConcurrencyOverruns​

Number of times we drop processing of a query profiler signal due to too many concurrent query profilers in other threads, which may indicate overload.

QueryProfilerErrors​

Invalid memory accesses during asynchronous stack unwinding.

QueryProfilerRuns​

Number of times QueryProfiler had been run.

QueryProfilerSignalOverruns​

Number of times we drop processing of a query profiler signal due to overrun plus the number of signals that OS has not delivered due to overrun.

QueryRemoteReadThrottlerBytes​

Bytes passed through 'max_remote_read_network_bandwidth' throttler.

QueryRemoteReadThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_remote_read_network_bandwidth' throttling.

QueryRemoteWriteThrottlerBytes​

Bytes passed through 'max_remote_write_network_bandwidth' throttler.

QueryRemoteWriteThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_remote_write_network_bandwidth' throttling.

QueryTimeMicroseconds​

Total time of all queries.

QuorumFailedInserts​

Number of inserts failed due to quorum not reaching.

QuorumParts​

Number of data parts written with quorum. It counts as one part for sync insert and maybe up to async inserts count for insert which flushes async inserts.

QuorumWaitMicroseconds​

Total time spent waiting for quorum during inserts.

RWLockAcquiredReadLocks​

Number of times a read lock was acquired (in a heavy RWLock).

RWLockAcquiredWriteLocks​

Number of times a write lock was acquired (in a heavy RWLock).

RWLockReadersWaitMilliseconds​

Total time spent waiting for a read lock to be acquired (in a heavy RWLock).

RWLockWritersWaitMilliseconds​

Total time spent waiting for a write lock to be acquired (in a heavy RWLock).

ReadBackoff​

Number of times the number of query processing threads was lowered due to slow reads.

ReadBufferFromAzureBytes​

Bytes read from Azure.

ReadBufferFromAzureInitMicroseconds​

Time spent initializing connection to Azure.

ReadBufferFromAzureMicroseconds​

Time spent on reading from Azure.

ReadBufferFromAzureRequestsErrors​

Number of exceptions while reading from Azure

ReadBufferFromFileDescriptorRead​

Number of reads (read/pread) from a file descriptor. Does not include sockets.

ReadBufferFromFileDescriptorReadBytes​

Number of bytes read from file descriptors. If the file is compressed, this will show the compressed data size.

ReadBufferFromFileDescriptorReadFailed​

Number of times the read (read/pread) from a file descriptor have failed.

ReadBufferFromS3Bytes​

Bytes read from S3.

ReadBufferFromS3InitMicroseconds​

Time spent initializing connection to S3.

ReadBufferFromS3Microseconds​

Time spent on reading from S3.

ReadBufferFromS3RequestsErrors​

Number of exceptions while reading from S3.

ReadBufferSeekCancelConnection​

Number of seeks which lead to new connection (s3, http)

ReadCompressedBytes​

Number of bytes (the number of bytes before decompression) read from compressed sources (files, network).

ReadPatchesMicroseconds​

Total time spent reading patch parts

ReadTaskRequestsReceived​

The number of callbacks requested from the remote server back to the initiator server to choose the read task (for s3Cluster table function and similar). Measured on the initiator server side.

ReadTaskRequestsSent​

The number of callbacks requested from the remote server back to the initiator server to choose the read task (for s3Cluster table function and similar). Measured on the remote server side.

ReadTaskRequestsSentElapsedMicroseconds​

Time spent in callbacks requested from the remote server back to the initiator server to choose the read task (for s3Cluster table function and similar). Measured on the remote server side.

ReadTasksWithAppliedMutationsOnFly​

Total number of read tasks for which there was any mutation applied on fly

ReadTasksWithAppliedPatches​

Total number of read tasks for which there was any patch part applied

ReadWriteBufferFromHTTPBytes​

Total size of payload bytes received and sent by ReadWriteBufferFromHTTP. Doesn't include HTTP headers.

ReadWriteBufferFromHTTPRequestsSent​

Number of HTTP requests sent by ReadWriteBufferFromHTTP

RealTimeMicroseconds​

Total (wall clock) time spent in processing (queries and other tasks) threads (note that this is a sum).

RebuiltProjections​

Number of projections rebuilt from scratch during MergeTree merges.

RefreshableViewLockTableRetry​

How many times a SELECT from refreshable materialized view had to switch to a new table because the old table was dropped

RefreshableViewRefreshFailed​

How many times refreshable materialized views failed to refresh

RefreshableViewRefreshSuccess​

How many times refreshable materialized views refreshed

RefreshableViewSyncReplicaRetry​

How many times a SELECT from refreshable materialized view failed and retried an implicit SYNC REPLICA

RefreshableViewSyncReplicaSuccess​

How many times a SELECT from refreshable materialized view did an implicit SYNC REPLICA

RegexpLocalCacheHit​

Number of times we fetched compiled regular expression from a local cache.

RegexpLocalCacheMiss​

Number of times we failed to fetch compiled regular expression from a local cache.

RegexpWithMultipleNeedlesCreated​

Regular expressions with multiple needles (VectorScan library) compiled.

RegexpWithMultipleNeedlesGlobalCacheHit​

Number of times we fetched compiled regular expression with multiple needles (VectorScan library) from the global cache.

RegexpWithMultipleNeedlesGlobalCacheMiss​

Number of times we failed to fetch compiled regular expression with multiple needles (VectorScan library) from the global cache.

RejectedInserts​

Number of times the INSERT of a block to a MergeTree table was rejected with 'Too many parts' exception due to high number of active data parts for partition.

RejectedLightweightUpdates​

Number of time the lightweight update was rejected due to too many uncompressed bytes in patches.

RejectedMutations​

Number of times the mutation of a MergeTree table was rejected with 'Too many mutations' exception due to high number of unfinished mutations for table.

RemoteFSBuffers​

Number of buffers created for asynchronous reading from remote filesystem

RemoteFSCancelledPrefetches​

Number of cancelled prefecthes (because of seek)

RemoteFSLazySeeks​

Number of lazy seeks

RemoteFSPrefetchedBytes​

Number of bytes from prefecthed buffer

RemoteFSPrefetchedReads​

Number of reads from prefecthed buffer

RemoteFSPrefetches​

Number of prefetches made with asynchronous reading from remote filesystem

RemoteFSSeeks​

Total number of seeks for async buffer

RemoteFSSeeksWithReset​

Number of seeks which lead to a new connection

RemoteFSUnprefetchedBytes​

Number of bytes from unprefetched buffer

RemoteFSUnprefetchedReads​

Number of reads from unprefetched buffer

RemoteFSUnusedPrefetches​

Number of prefetches pending at buffer destruction

RemoteReadThrottlerBytes​

Bytes passed through 'max_remote_read_network_bandwidth_for_server'/'max_remote_read_network_bandwidth' throttler.

RemoteReadThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_remote_read_network_bandwidth_for_server'/'max_remote_read_network_bandwidth' throttling.

RemoteWriteThrottlerBytes​

Bytes passed through 'max_remote_write_network_bandwidth_for_server'/'max_remote_write_network_bandwidth' throttler.

RemoteWriteThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_remote_write_network_bandwidth_for_server'/'max_remote_write_network_bandwidth' throttling.

ReplacingSortedMilliseconds​

Total time spent while replacing sorted columns

ReplicaPartialShutdown​

How many times Replicated table has to deinitialize its state due to session expiration in ZooKeeper. The state is reinitialized every time when ZooKeeper is available again.

ReplicatedCoveredPartsInZooKeeperOnStart​

For debugging purposes. Number of parts in ZooKeeper that have a covering part, but doesn't exist on disk. Checked on server start.

ReplicatedDataLoss​

Number of times a data part that we wanted doesn't exist on any replica (even on replicas that are offline right now). That data parts are definitely lost. This is normal due to asynchronous replication (if quorum inserts were not enabled), when the replica on which the data part was written was failed and when it became online after fail it doesn't contain that data part.

ReplicatedPartChecks​

Number of times we had to perform advanced search for a data part on replicas or to clarify the need of an existing data part.

ReplicatedPartChecksFailed​

Number of times the advanced search for a data part on replicas did not give result or when unexpected part has been found and moved away.

ReplicatedPartFailedFetches​

Number of times a data part was failed to download from replica of a ReplicatedMergeTree table.

ReplicatedPartFetches​

Number of times a data part was downloaded from replica of a ReplicatedMergeTree table.

ReplicatedPartFetchesOfMerged​

Number of times we prefer to download already merged part from replica of ReplicatedMergeTree table instead of performing a merge ourself (usually we prefer doing a merge ourself to save network traffic). This happens when we have not all source parts to perform a merge or when the data part is old enough.

ReplicatedPartMerges​

Number of times data parts of ReplicatedMergeTree tables were successfully merged.

ReplicatedPartMutations​

Number of times data parts of ReplicatedMergeTree tables were successfully mutated.

RestorePartsSkippedBytes​

Total size of files skipped while restoring parts

RestorePartsSkippedFiles​

Number of files skipped while restoring parts

RowsReadByMainReader​

Number of rows read from MergeTree tables by the main reader (after PREWHERE step).

RowsReadByPrewhereReaders​

Number of rows read from MergeTree tables (in total) by prewhere readers.

RuntimeDataflowStatisticsInputBytes​

Collected statistics on the number of bytes replicas would read if the query was executed with parallel replicas

RuntimeDataflowStatisticsOutputBytes​

Collected statistics on the number of bytes replicas would send to the initiator if the query was executed with parallel replicas

RuntimeFilterBlocksProcessed​

Number of blocks processed by JOIN Runtime Filters

RuntimeFilterBlocksSkipped​

Number of blocks skipped by JOIN Runtime Filters without processing due to filter being dynamically disabled because of poor filtering ratio

RuntimeFilterRowsChecked​

Number of rows checked by JOIN Runtime Filters

RuntimeFilterRowsPassed​

Number of rows that passed (not filtered out by) JOIN Runtime Filters

RuntimeFilterRowsSkipped​

Number of rows in blocks that were skipped by JOIN Runtime Filters

RuntimeFiltersCreated​

Number of distinct JOIN Runtime Filters created within a query

S3AbortMultipartUpload​

Number of S3 API AbortMultipartUpload calls.

S3CachedCredentialsProvidersAdded​

Total number of newly added credentials providers to the cache

S3CachedCredentialsProvidersReused​

Total number of reused credentials provider from the cache

S3Clients​

Number of created S3 clients.

S3CompleteMultipartUpload​

Number of S3 API CompleteMultipartUpload calls.

S3CopyObject​

Number of S3 API CopyObject calls.

S3CreateMultipartUpload​

Number of S3 API CreateMultipartUpload calls.

S3DeleteObjects​

Number of S3 API DeleteObject(s) calls.

S3GetObject​

Number of S3 API GetObject calls.

S3GetObjectTagging​

Number of S3 API GetObjectTagging calls.

S3GetRequestThrottlerBlocked​

Number of S3 GET and SELECT requests blocked by throttler.

S3GetRequestThrottlerCount​

Number of S3 GET and SELECT requests passed through throttler: blocked and not blocked.

S3GetRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform S3 GET and SELECT request throttling.

S3HeadObject​

Number of S3 API HeadObject calls.

S3ListObjects​

Number of S3 API ListObjects calls.

S3PutObject​

Number of S3 API PutObject calls.

S3PutRequestThrottlerBlocked​

Number of S3 PUT, COPY, POST and LIST requests blocked by throttler.

S3PutRequestThrottlerCount​

Number of S3 PUT, COPY, POST and LIST requests passed through throttler: blocked and not blocked.

S3PutRequestThrottlerSleepMicroseconds​

Total time a query was sleeping to conform S3 PUT, COPY, POST and LIST request throttling.

S3QueueSetFileFailedMicroseconds​

Time spent to set file as failed

S3QueueSetFileProcessedMicroseconds​

Time spent to set file as processed

S3QueueSetFileProcessingMicroseconds​

Time spent to set file as processing

S3ReadMicroseconds​

Time of GET and HEAD requests to S3 storage.

S3ReadRequestAttempts​

Number of attempts for GET and HEAD requests, including the initial try and any retries, but excluding retries performed internally by the S3 retry strategy

S3ReadRequestRetryableErrors​

Number of retryable errors for GET and HEAD requests, excluding retries performed internally by the S3 retry strategy

S3ReadRequestsCount​

Number of GET and HEAD requests to S3 storage.

S3ReadRequestsErrors​

Number of non-throttling errors in GET and HEAD requests to S3 storage.

S3ReadRequestsRedirects​

Number of redirects in GET and HEAD requests to S3 storage.

S3ReadRequestsThrottling​

Number of 429 and 503 errors in GET and HEAD requests to S3 storage.

S3UploadPart​

Number of S3 API UploadPart calls.

S3UploadPartCopy​

Number of S3 API UploadPartCopy calls.

S3WriteMicroseconds​

Time of POST, DELETE, PUT and PATCH requests to S3 storage.

S3WriteRequestAttempts​

Number of attempts for POST, DELETE, PUT and PATCH requests, including the initial try and any retries, but excluding retries performed internally by the retry strategy

S3WriteRequestRetryableErrors​

Number of retryable errors for POST, DELETE, PUT and PATCH requests, excluding retries performed internally by the retry strategy

S3WriteRequestsCount​

Number of POST, DELETE, PUT and PATCH requests to S3 storage.

S3WriteRequestsErrors​

Number of non-throttling errors in POST, DELETE, PUT and PATCH requests to S3 storage.

S3WriteRequestsRedirects​

Number of redirects in POST, DELETE, PUT and PATCH requests to S3 storage.

S3WriteRequestsThrottling​

Number of 429 and 503 errors in POST, DELETE, PUT and PATCH requests to S3 storage.

ScalarSubqueriesCacheMiss​

Number of times a read from a scalar subquery was not cached and had to be calculated completely

ScalarSubqueriesGlobalCacheHit​

Number of times a read from a scalar subquery was done using the global cache

ScalarSubqueriesLocalCacheHit​

Number of times a read from a scalar subquery was done using the local cache

SchedulerIOReadBytes​

Bytes passed through scheduler for IO reads.

SchedulerIOReadRequests​

Resource requests passed through scheduler for IO reads.

SchedulerIOReadWaitMicroseconds​

Total time a query was waiting on resource requests for IO reads.

SchedulerIOWriteBytes​

Bytes passed through scheduler for IO writes.

SchedulerIOWriteRequests​

Resource requests passed through scheduler for IO writes.

SchedulerIOWriteWaitMicroseconds​

Total time a query was waiting on resource requests for IO writes.

SchemaInferenceCacheEvictions​

Number of times a schema from cache was evicted due to overflow

SchemaInferenceCacheHits​

Number of times the requested source is found in schema cache

SchemaInferenceCacheInvalidations​

Number of times a schema in cache became invalid due to changes in data

SchemaInferenceCacheMisses​

Number of times the requested source is not in schema cache

SchemaInferenceCacheNumRowsHits​

Number of times the number of rows is found in schema cache during count from files

SchemaInferenceCacheNumRowsMisses​

Number of times the requested source is in cache but the number of rows is not in cache while count from files

SchemaInferenceCacheSchemaHits​

Number of times the schema is found in schema cache during schema inference

SchemaInferenceCacheSchemaMisses​

Number of times the requested source is in cache but the schema is not in cache during schema inference

Seek​

Number of times the 'lseek' function was called.

SelectQueriesWithPrimaryKeyUsage​

Count SELECT queries which use the primary key to evaluate the WHERE condition

SelectQueriesWithSubqueries​

Count SELECT queries with all subqueries

SelectQuery​

Same as Query, but only for SELECT queries.

SelectQueryTimeMicroseconds​

Total time of SELECT queries.

SelectedBytes​

Number of bytes (uncompressed; for columns as they stored in memory) SELECTed from all tables.

SelectedMarks​

Number of marks (index granules) selected to read from a MergeTree table.

SelectedMarksTotal​

Number of total marks (index granules) before selecting which ones to read from a MergeTree table.

SelectedParts​

Number of data parts selected to read from a MergeTree table.

SelectedPartsTotal​

Number of total data parts before selecting which ones to read from a MergeTree table.

SelectedRanges​

Number of (non-adjacent) ranges in all data parts selected to read from a MergeTree table.

SelectedRows​

Number of rows SELECTed from all tables.

SelfDuplicatedAsyncInserts​

Number of async inserts in the INSERTed block to a ReplicatedMergeTree table was self deduplicated.

ServerStartupMilliseconds​

Time elapsed from starting server to listening to sockets in milliseconds

Shards​

The number of shards involved in a query, summed across all distributed tables and table functions. A single host is counted multiple times if it appears in multiple tables. The number counts the total expected number of shards, which includes skipped shards with the skip_unavailable_shards setting.

SharedDatabaseCatalogFailedToApplyState​

Number of failures to apply new state in SharedDatabaseCatalog

SharedDatabaseCatalogStateApplicationMicroseconds​

Total time spend on application of new state in SharedDatabaseCatalog

SharedMergeTreeCondemnedPartsKillRequest​

How many ZooKeeper requests were used to remove condemned parts

SharedMergeTreeCondemnedPartsLockConflict​

How many times we failed to acquire lock because of conflict

SharedMergeTreeCondemnedPartsRemoved​

How many condemned parts were removed

SharedMergeTreeDataPartsFetchAttempt​

How many times we tried to fetch data parts

SharedMergeTreeDataPartsFetchFromPeer​

How many times we fetch data parts from peer

SharedMergeTreeDataPartsFetchFromPeerMicroseconds​

Data parts fetch from peer microseconds

SharedMergeTreeDataPartsFetchFromS3​

How many times we fetch data parts from S3

SharedMergeTreeHandleBlockingParts​

How many blocking parts to handle in scheduleDataProcessingJob

SharedMergeTreeHandleBlockingPartsMicroseconds​

Time of handling blocking parts in scheduleDataProcessingJob

SharedMergeTreeHandleFetchPartsMicroseconds​

Time of handling fetched parts in scheduleDataProcessingJob

SharedMergeTreeHandleOutdatedParts​

How many outdated parts to handle in scheduleDataProcessingJob

SharedMergeTreeHandleOutdatedPartsMicroseconds​

Time of handling outdated parts in scheduleDataProcessingJob

SharedMergeTreeLoadChecksumAndIndexesMicroseconds​

Time of loadColumnsChecksumsIndexes only for SharedMergeTree

SharedMergeTreeMergeMutationAssignmentAttempt​

How many times we tried to assign merge or mutation

SharedMergeTreeMergeMutationAssignmentFailedWithConflict​

How many times we tried to assign merge or mutation and failed because of conflict in Keeper

SharedMergeTreeMergeMutationAssignmentFailedWithNothingToDo​

How many times we tried to assign merge or mutation and failed because nothing to merge

SharedMergeTreeMergeMutationAssignmentSuccessful​

How many times we tried to assign merge or mutation

SharedMergeTreeMergePartsMovedToCondemned​

How many parts moved to condemned directory

SharedMergeTreeMergePartsMovedToOudated​

How many parts moved to outdated directory

SharedMergeTreeMergeSelectingTaskMicroseconds​

Merge selecting task microseconds for SMT

SharedMergeTreeMetadataCacheHintLoadedFromCache​

Number of times metadata cache hint was found without going to Keeper

SharedMergeTreeOptimizeAsync​

Asynchronous OPTIMIZE queries executed

SharedMergeTreeOptimizeSync​

Synchronous OPTIMIZE queries executed

SharedMergeTreeOutdatedPartsConfirmationInvocations​

How many invocations were made to confirm outdated parts

SharedMergeTreeOutdatedPartsConfirmationRequest​

How many ZooKeeper requests were used to config outdated parts

SharedMergeTreeOutdatedPartsHTTPRequest​

How many HTTP requests were send to confirm outdated parts

SharedMergeTreeOutdatedPartsHTTPResponse​

How many HTTP responses were send to confirm outdated parts

SharedMergeTreePartsKillerMicroseconds​

How much time does parts killer main thread takes

SharedMergeTreePartsKillerParts​

How many parts has been scheduled by the killer

SharedMergeTreePartsKillerPartsMicroseconds​

How many time does it take to remove parts (executed from multiple threads)

SharedMergeTreePartsKillerRuns​

How many times parts killer has been running

SharedMergeTreeReplicaSetUpdateTaskRuns​

Number of times updateReplicaSetTask has run

SharedMergeTreeReplicaSetUpdatesFromZooKeeper​

How many times we have update replica set from ZooKeeper

SharedMergeTreeReplicaSetUpdatesFromZooKeeperMicroseconds​

How much time we spend to update replica set

SharedMergeTreeReplicaSetUpdatesFromZooKeeperRequests​

How many total ZooKeeper requests we made to update replica set

SharedMergeTreeScheduleDataProcessingJob​

How many times scheduleDataProcessingJob called/

SharedMergeTreeScheduleDataProcessingJobMicroseconds​

scheduleDataProcessingJob execute time

SharedMergeTreeScheduleDataProcessingJobNothingToScheduled​

How many times scheduleDataProcessingJob called but nothing to do

SharedMergeTreeSelectPartsForCoordinatedFetchMicroseconds​

Time of selectPartsForCoordinatedFetch

SharedMergeTreeSelectPartsForCoordinatedFetchParts​

Number of parts selected by selectPartsForCoordinatedFetch

SharedMergeTreeSelectPartsForFullFetchMicroseconds​

Time of selectPartsForFullFetch

SharedMergeTreeSelectPartsForFullFetchParts​

Number of parts selected by selectPartsForFullFetch

SharedMergeTreeSelectPartsForRendezvousFetchMicroseconds​

Time of selectPartsForRendezvousFetch

SharedMergeTreeSelectPartsForRendezvousFetchParts​

Number of parts selected by selectPartsForRendezvousFetch

SharedMergeTreeSnapshotPartsCleanRequest​

How many times SnapshotCleanerThread decides to clean a part

SharedMergeTreeSnapshotPartsCleanerMicroseconds​

How long time SnapshotCleanerThread has run

SharedMergeTreeSnapshotPartsCleanerParts​

How long time SnapshotCleanerThread tries to clean a part

SharedMergeTreeSnapshotPartsCleanerPartsMicroseconds​

How long time SnapshotCleanerThread takes to clean parts

SharedMergeTreeSnapshotPartsCleanerRuns​

How many times SnapshotCleanerThread runs

SharedMergeTreeSnapshotPartsRemoved​

How many times SnapshotCleanerThread successfully clean a part

SharedMergeTreeTryUpdateDiskMetadataCacheForPartMicroseconds​

Time of tryUpdateDiskMetadataCacheForPart in scheduleDataProcessingJob

SharedMergeTreeVirtualPartsUpdateMicroseconds​

Virtual parts update microseconds

SharedMergeTreeVirtualPartsUpdates​

Virtual parts update count

SharedMergeTreeVirtualPartsUpdatesByLeader​

Virtual parts updates by leader

SharedMergeTreeVirtualPartsUpdatesForMergesOrStatus​

Virtual parts updates from non-default background job

SharedMergeTreeVirtualPartsUpdatesFromPeer​

Virtual parts updates count from peer

SharedMergeTreeVirtualPartsUpdatesFromPeerMicroseconds​

Virtual parts updates from peer microseconds

SharedMergeTreeVirtualPartsUpdatesFromZooKeeper​

Virtual parts updates count from ZooKeeper

SharedMergeTreeVirtualPartsUpdatesFromZooKeeperMicroseconds​

Virtual parts updates from ZooKeeper microseconds

SharedMergeTreeVirtualPartsUpdatesLeaderFailedElection​

Virtual parts updates leader election failed

SharedMergeTreeVirtualPartsUpdatesLeaderSuccessfulElection​

Virtual parts updates leader election successful

SharedMergeTreeVirtualPartsUpdatesPeerNotFound​

Virtual updates from peer failed because no one found

SharedPartsLockHoldMicroseconds​

Total time spent holding shared data parts lock in MergeTree tables

SharedPartsLockWaitMicroseconds​

Total time spent waiting for shared data parts lock in MergeTree tables

SharedPartsLocks​

Number of times shared data parts lock has been acquired for MergeTree tables

SleepFunctionCalls​

Number of times a sleep function (sleep, sleepEachRow) has been called.

SleepFunctionElapsedMicroseconds​

Time spent sleeping in a sleep function (sleep, sleepEachRow).

SleepFunctionMicroseconds​

Time set to sleep in a sleep function (sleep, sleepEachRow).

SlowRead​

Number of reads from a file that were slow. This indicate system overload. Thresholds are controlled by read_backoff_* settings.

SoftPageFaults​

The number of soft page faults in query execution threads. Soft page fault usually means a miss in the memory allocator cache, which requires a new memory mapping from the OS and subsequent allocation of a page of physical memory.

StorageBufferErrorOnFlush​

Number of times a buffer in the 'Buffer' table has not been able to flush due to error writing in the destination table.

StorageBufferFlush​

Number of times a buffer in a 'Buffer' table was flushed.

StorageBufferLayerLockReadersWaitMilliseconds​

Time for waiting for Buffer layer during reading.

StorageBufferLayerLockWritersWaitMilliseconds​

Time for waiting free Buffer layer to write to (can be used to tune Buffer layers).

StorageBufferPassedAllMinThresholds​

Number of times a criteria on min thresholds has been reached to flush a buffer in a 'Buffer' table.

StorageBufferPassedBytesFlushThreshold​

Number of times background-only flush threshold on bytes has been reached to flush a buffer in a 'Buffer' table. This is expert-only metric. If you read this and you are not an expert, stop reading.

StorageBufferPassedBytesMaxThreshold​

Number of times a criteria on max bytes threshold has been reached to flush a buffer in a 'Buffer' table.

StorageBufferPassedRowsFlushThreshold​

Number of times background-only flush threshold on rows has been reached to flush a buffer in a 'Buffer' table. This is expert-only metric. If you read this and you are not an expert, stop reading.

StorageBufferPassedRowsMaxThreshold​

Number of times a criteria on max rows threshold has been reached to flush a buffer in a 'Buffer' table.

StorageBufferPassedTimeFlushThreshold​

Number of times background-only flush threshold on time has been reached to flush a buffer in a 'Buffer' table. This is expert-only metric. If you read this and you are not an expert, stop reading.

StorageBufferPassedTimeMaxThreshold​

Number of times a criteria on max time threshold has been reached to flush a buffer in a 'Buffer' table.

StorageConnectionsCreated​

Number of created connections for storages

StorageConnectionsElapsedMicroseconds​

Total time spend on creating connections for storages

StorageConnectionsErrors​

Number of cases when creation of a connection for storage is failed

StorageConnectionsExpired​

Number of expired connections for storages

StorageConnectionsPreserved​

Number of preserved connections for storages

StorageConnectionsReset​

Number of reset connections for storages

StorageConnectionsReused​

Number of reused connections for storages

SummingSortedMilliseconds​

Total time spent while summing sorted columns

SuspendSendingQueryToShard​

Total count when sending query to shard was suspended when async_query_sending_for_remote is enabled.

SynchronousReadWaitMicroseconds​

Time spent in waiting for synchronous reads in asynchronous local read.

SynchronousRemoteReadWaitMicroseconds​

Time spent in waiting for synchronous remote reads.

SystemLogErrorOnFlush​

Number of times any of the system logs have failed to flush to the corresponding system table. Attempts to flush are repeated.

SystemTimeMicroseconds​

Total time spent in processing (queries and other tasks) threads executing CPU instructions in OS kernel mode. This is time spent in syscalls, excluding waiting time during blocking syscalls.

TableFunctionExecute​

Number of table function calls.

TextIndexDiscardHint​

Number of index granules where a direct reading from the text index was added as hint and was discarded due to low selectivity.

TextIndexDiscardPatternScan​

Number of times pattern-based dictionary scan in a text index was discarded because the number of posting lists to read exceeded the threshold.

TextIndexHeaderCacheHits​

Number of times a header has been found in the cache.

TextIndexHeaderCacheMisses​

Number of times a header has not been found in the cache.

TextIndexLazyAdvanceCount​

Number of advance operations performed in lazy posting list mode.

TextIndexLazyAndBlocksSkippedZero​

Number of packed blocks skipped because the output region was all-zeros in lazy AND mode.

TextIndexLazyAndSegmentsSkippedDense​

Number of segments skipped via dense-increment optimization in lazy AND mode.

TextIndexLazyAndSegmentsSkippedZero​

Number of segments skipped because the output region was all-zeros in lazy AND mode.

TextIndexLazyBlocksSkippedCovered​

Number of packed blocks skipped because the output region was already all-ones in lazy posting list mode.

TextIndexLazyBruteForceIntersections​

Number of brute-force intersections performed in lazy posting list mode.

TextIndexLazyLeapfrogIntersections​

Number of leapfrog intersections performed in lazy posting list mode.

TextIndexLazyPackedBlocksDecoded​

Number of packed blocks decoded in lazy posting list mode.

TextIndexLazySegmentsPrepared​

Number of segments prepared (Index Section loaded) in lazy posting list mode.

TextIndexLazySegmentsSkippedCovered​

Number of segments skipped because the output region was already all-ones in lazy posting list mode.

TextIndexLazySegmentsSkippedDense​

Number of segments skipped via dense-memset optimization in lazy posting list mode.

TextIndexPostingsCacheHits​

Number of times a text index posting list has been found in the cache.

TextIndexPostingsCacheMisses​

Number of times a a text index posting list has not been found in the cache.

TextIndexReadDictionaryBlocks​

Number of times a text index dictionary block has been read from disk.

TextIndexReadGranulesMicroseconds​

Total time spent reading and analyzing granules of the text index.

TextIndexReadPostings​

Number of times a posting list has been read from the text index.

TextIndexReadSparseIndexBlocks​

Number of times a sparse index block has been read from the text index.

TextIndexReaderTotalMicroseconds​

Total time spent reading the text index.

TextIndexTokensCacheHits​

Number of times a text index token info has been found in the cache.

TextIndexTokensCacheMisses​

Number of times a text index token info has not been found in the cache.

TextIndexUseHint​

Number of index granules where a direct reading from the text index was added as hint and was used.

TextIndexUsedEmbeddedPostings​

Number of times a posting list embedded in the dictionary has been used.

ThreadPoolReaderPageCacheHit​

Number of times the read inside ThreadPoolReader was done from the page cache.

ThreadPoolReaderPageCacheHitBytes​

Number of bytes read inside ThreadPoolReader when it was done from the page cache.

ThreadPoolReaderPageCacheHitElapsedMicroseconds​

Time spent reading data from page cache in ThreadPoolReader.

ThreadPoolReaderPageCacheMiss​

Number of times the read inside ThreadPoolReader was not done from page cache and was hand off to thread pool.

ThreadPoolReaderPageCacheMissBytes​

Number of bytes read inside ThreadPoolReader when read was not done from page cache and was hand off to thread pool.

ThreadPoolReaderPageCacheMissElapsedMicroseconds​

Time spent reading data inside the asynchronous job in ThreadPoolReader - when read was not done from the page cache.

ThreadpoolReaderPrepareMicroseconds​

Time spent on preparation (e.g. call to reader seek() method)

ThreadpoolReaderReadBytes​

Bytes read from a threadpool task in asynchronous reading

ThreadpoolReaderSubmit​

Bytes read from a threadpool task in asynchronous reading

ThreadpoolReaderSubmitLookupInCacheMicroseconds​

How much time we spent checking if content is cached

ThreadpoolReaderSubmitReadSynchronously​

How many times we haven't scheduled a task on the thread pool and read synchronously instead

ThreadpoolReaderSubmitReadSynchronouslyBytes​

How many bytes were read synchronously

ThreadpoolReaderSubmitReadSynchronouslyMicroseconds​

How much time we spent reading synchronously

ThreadpoolReaderTaskMicroseconds​

Time spent getting the data in asynchronous reading

ThrottlerSleepMicroseconds​

Total time a query was sleeping to conform all throttling settings.

TinyS3Clients​

Number of S3 clients copies which reuse an existing auth provider from another client.

USearchAddComputedDistances​

Number of times distance was computed when adding vectors to usearch indexes.

USearchAddCount​

Number of vectors added to usearch indexes.

USearchAddVisitedMembers​

Number of nodes visited when adding vectors to usearch indexes.

USearchSearchComputedDistances​

Number of times distance was computed when searching usearch indexes.

USearchSearchCount​

Number of search operations performed in usearch indexes.

USearchSearchVisitedMembers​

Number of nodes visited when searching in usearch indexes.

UncompressedCacheHits​

Number of times a block of data has been found in the uncompressed cache (and decompression was avoided).

UncompressedCacheMisses​

Number of times a block of data has not been found in the uncompressed cache (and required decompression).

UncompressedCacheWeightLost​

Number of bytes evicted from the uncompressed cache.

UserThrottlerBytes​

Bytes passed through 'max_network_bandwidth_for_user' throttler.

UserThrottlerSleepMicroseconds​

Total time a query was sleeping to conform 'max_network_bandwidth_for_user' throttling.

UserTimeMicroseconds​

Total time spent in processing (queries and other tasks) threads executing CPU instructions in user mode. This includes time CPU pipeline was stalled due to main memory access, cache misses, branch mispredictions, hyper-threading, etc.

VectorSimilarityIndexCacheHits​

Number of times an index granule has been found in the vector index cache.

VectorSimilarityIndexCacheMisses​

Number of times an index granule has not been found in the vector index cache and had to be read from disk.

VectorSimilarityIndexCacheWeightLost​

Approximate number of bytes evicted from the vector index cache.

VersionedCollapsingSortedMilliseconds​

Total time spent while version collapsing sorted columns

WaitMarksLoadMicroseconds​

Time spent loading marks

WaitPrefetchTaskMicroseconds​

Time spend waiting for prefetched reader

WasmDeserializationMicroseconds​

Time spent executing WebAssembly code

WasmGuestExecuteMicroseconds​

Time spent executing WebAssembly code

WasmMemoryAllocated​

Total memory allocated for WebAssembly compartments

WasmModuleInstatiate​

Number of WebAssembly compartments created

WasmSerializationMicroseconds​

Time spent executing WebAssembly code

WasmTotalExecuteMicroseconds​

Time spent executing WebAssembly code

WriteBufferFromFileDescriptorWrite​

Number of writes (write/pwrite) to a file descriptor. Does not include sockets.

WriteBufferFromFileDescriptorWriteBytes​

Number of bytes written to file descriptors. If the file is compressed, this will show compressed data size.

WriteBufferFromFileDescriptorWriteFailed​

Number of times the write (write/pwrite) to a file descriptor have failed.

WriteBufferFromHTTPBytes​

Total size of payload bytes received and sent by WriteBufferFromHTTP. Doesn't include HTTP headers.

WriteBufferFromHTTPRequestsSent​

Number of HTTP requests sent by WriteBufferFromHTTP

WriteBufferFromS3Bytes​

Bytes written to S3.

WriteBufferFromS3Microseconds​

Time spent on writing to S3.

WriteBufferFromS3RequestsErrors​

Number of exceptions while writing to S3.

WriteBufferFromS3WaitInflightLimitMicroseconds​

Time spent on waiting while some of the current requests are done when its number reached the limit defined by s3_max_inflight_parts_for_one_file.

ZooKeeperBytesReceived​

Number of bytes received over network while communicating with ZooKeeper.

ZooKeeperBytesSent​

Number of bytes send over network while communicating with ZooKeeper.

ZooKeeperCheck​

Number of 'check' requests to ZooKeeper. Usually they don't make sense in isolation, only as part of a complex transaction.

ZooKeeperClose​

Number of times connection with ZooKeeper has been closed voluntary.

ZooKeeperCreate​

Number of 'create' requests to ZooKeeper.

ZooKeeperExists​

Number of 'exists' requests to ZooKeeper.

ZooKeeperGet​

Number of 'get' requests to ZooKeeper.

ZooKeeperGetACL​

Number of 'getACL' requests to ZooKeeper.

ZooKeeperHardwareExceptions​

Number of exceptions while working with ZooKeeper related to network (connection loss or similar).

ZooKeeperInit​

Number of times connection with ZooKeeper has been established.

ZooKeeperList​

Number of 'list' (getChildren) requests to ZooKeeper.

ZooKeeperListRecursive​

Number of 'listRecursive' requests to ZooKeeper.

ZooKeeperMulti​

Number of 'multi' requests to ZooKeeper (compound transactions).

ZooKeeperMultiRead​

Number of read 'multi' requests to ZooKeeper (compound transactions).

ZooKeeperMultiWrite​

Number of write 'multi' requests to ZooKeeper (compound transactions).

ZooKeeperOtherExceptions​

Number of exceptions while working with ZooKeeper other than ZooKeeperUserExceptions and ZooKeeperHardwareExceptions.

ZooKeeperReconfig​

Number of 'reconfig' requests to ZooKeeper.

ZooKeeperRemove​

Number of 'remove' requests to ZooKeeper.

ZooKeeperSet​

Number of 'set' requests to ZooKeeper.

ZooKeeperSync​

Number of 'sync' requests to ZooKeeper. These requests are rarely needed or usable.

ZooKeeperTransactions​

Number of ZooKeeper operations, which include both read and write operations as well as multi-transactions.

ZooKeeperUserExceptions​

Number of exceptions while working with ZooKeeper related to the data (no node, bad version or similar).

ZooKeeperWaitMicroseconds​

Number of microseconds spent waiting for responses from ZooKeeper after creating a request, summed across all the requesting threads.

ZooKeeperWatchResponse​

Number of times watch notification has been received from ZooKeeper.