druid/docs/operations/metrics.md

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metrics Metrics

You can configure Druid to emit metrics that are essential for monitoring query execution, ingestion, coordination, and so on.

All Druid metrics share a common set of fields:

  • timestamp: the time the metric was created
  • metric: the name of the metric
  • service: the service name that emitted the metric
  • host: the host name that emitted the metric
  • value: some numeric value associated with the metric

Metrics may have additional dimensions beyond those listed above.

:::info Most metric values reset each emission period, as specified in druid.monitoring.emissionPeriod. :::

Query metrics

Router

Metric Description Dimensions Normal value
query/time Milliseconds taken to complete a query. Native Query: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id. < 1s

Broker

Metric Description Dimensions Normal value
query/time Milliseconds taken to complete a query.

Common: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id.

Aggregation Queries: numMetrics, numComplexMetrics.

GroupBy: numDimensions.

TopN: threshold, dimension.

< 1s
query/bytes The total number of bytes returned to the requesting client in the query response from the broker. Other services report the total bytes for their portion of the query.

Common: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id.

Aggregation Queries: numMetrics, numComplexMetrics.

GroupBy: numDimensions.

TopN: threshold, dimension.

query/node/time Milliseconds taken to query individual historical/realtime processes. id, status, server < 1s
query/node/bytes Number of bytes returned from querying individual historical/realtime processes. id, status, server
query/node/ttfb Time to first byte. Milliseconds elapsed until Broker starts receiving the response from individual historical/realtime processes. id, status, server < 1s
query/node/backpressure Milliseconds that the channel to this process has spent suspended due to backpressure. id, status, server.
query/count Number of total queries. This metric is only available if the QueryCountStatsMonitor module is included.
query/success/count Number of queries successfully processed. This metric is only available if the QueryCountStatsMonitor module is included.
query/failed/count Number of failed queries. This metric is only available if the QueryCountStatsMonitor module is included.
query/interrupted/count Number of queries interrupted due to cancellation. This metric is only available if the QueryCountStatsMonitor module is included.
query/timeout/count Number of timed out queries. This metric is only available if the QueryCountStatsMonitor module is included.
mergeBuffer/pendingRequests Number of requests waiting to acquire a batch of buffers from the merge buffer pool. This metric is only available if the QueryCountStatsMonitor module is included.
query/segments/count This metric is not enabled by default. See the QueryMetrics Interface for reference regarding enabling this metric. Number of segments that will be touched by the query. In the broker, it makes a plan to distribute the query to realtime tasks and historicals based on a snapshot of segment distribution state. If there are some segments moved after this snapshot is created, certain historicals and realtime tasks can report those segments as missing to the broker. The broker will resend the query to the new servers that serve those segments after move. In this case, those segments can be counted more than once in this metric. Varies
query/priority Assigned lane and priority, only if Laning strategy is enabled. Refer to Laning strategies lane, dataSource, type 0
sqlQuery/time Milliseconds taken to complete a SQL query. id, nativeQueryIds, dataSource, remoteAddress, success, engine < 1s
sqlQuery/planningTimeMs Milliseconds taken to plan a SQL to native query. id, nativeQueryIds, dataSource, remoteAddress, success, engine
sqlQuery/bytes Number of bytes returned in the SQL query response. id, nativeQueryIds, dataSource, remoteAddress, success, engine
serverview/init/time Time taken to initialize the broker server view. Useful to detect if brokers are taking too long to start. Depends on the number of segments.
metadatacache/init/time Time taken to initialize the broker segment metadata cache. Useful to detect if brokers are taking too long to start Depends on the number of segments.
metadatacache/refresh/count Number of segments to refresh in broker segment metadata cache. dataSource
metadatacache/refresh/time Time taken to refresh segments in broker segment metadata cache. dataSource
serverview/sync/healthy Sync status of the Broker with a segment-loading server such as a Historical or Peon. Emitted only when HTTP-based server view is enabled. This metric can be used in conjunction with serverview/sync/unstableTime to debug slow startup of Brokers. server, tier 1 for fully synced servers, 0 otherwise
serverview/sync/unstableTime Time in milliseconds for which the Broker has been failing to sync with a segment-loading server. Emitted only when HTTP-based server view is enabled. server, tier Not emitted for synced servers.
subquery/rowLimit/count Number of subqueries whose results are materialized as rows (Java objects on heap). This metric is only available if the SubqueryCountStatsMonitor module is included.
subquery/byteLimit/count Number of subqueries whose results are materialized as frames (Druid's internal byte representation of rows). This metric is only available if the SubqueryCountStatsMonitor module is included.
subquery/fallback/count Number of subqueries which cannot be materialized as frames This metric is only available if the SubqueryCountStatsMonitor module is included.
subquery/fallback/insufficientType/count Number of subqueries which cannot be materialized as frames due to insufficient type information in the row signature. This metric is only available if the SubqueryCountStatsMonitor module is included.
subquery/fallback/unknownReason/count Number of subqueries which cannot be materialized as frames due other reasons. This metric is only available if the SubqueryCountStatsMonitor module is included.
query/rowLimit/exceeded/count Number of queries whose inlined subquery results exceeded the given row limit This metric is only available if the SubqueryCountStatsMonitor module is included.
query/byteLimit/exceeded/count Number of queries whose inlined subquery results exceeded the given byte limit This metric is only available if the SubqueryCountStatsMonitor module is included.

Historical

Metric Description Dimensions Normal value
query/time Milliseconds taken to complete a query.

Common: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id.

Aggregation Queries: numMetrics, numComplexMetrics.

GroupBy: numDimensions.

TopN: threshold, dimension.

< 1s
query/segment/time Milliseconds taken to query individual segment. Includes time to page in the segment from disk. id, status, segment, vectorized. several hundred milliseconds
query/wait/time Milliseconds spent waiting for a segment to be scanned. id, segment < several hundred milliseconds
segment/scan/pending Number of segments in queue waiting to be scanned. Close to 0
segment/scan/active Number of segments currently scanned. This metric also indicates how many threads from druid.processing.numThreads are currently being used. Close to druid.processing.numThreads
query/segmentAndCache/time Milliseconds taken to query individual segment or hit the cache (if it is enabled on the Historical process). id, segment several hundred milliseconds
query/cpu/time Microseconds of CPU time taken to complete a query.

Common: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id.

Aggregation Queries: numMetrics, numComplexMetrics.

GroupBy: numDimensions.

TopN: threshold, dimension.

Varies
query/count Total number of queries. This metric is only available if the QueryCountStatsMonitor module is included.
query/success/count Number of queries successfully processed. This metric is only available if the QueryCountStatsMonitor module is included.
query/failed/count Number of failed queries. This metric is only available if the QueryCountStatsMonitor module is included.
query/interrupted/count Number of queries interrupted due to cancellation. This metric is only available if the QueryCountStatsMonitor module is included.
query/timeout/count Number of timed out queries. This metric is only available if the QueryCountStatsMonitor module is included.
mergeBuffer/pendingRequests Number of requests waiting to acquire a batch of buffers from the merge buffer pool. This metric is only available if the QueryCountStatsMonitor module is included.

Real-time

Metric Description Dimensions Normal value
query/time Milliseconds taken to complete a query.

Common: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id.

Aggregation Queries: numMetrics, numComplexMetrics.

GroupBy: numDimensions.

TopN: threshold, dimension.

< 1s
query/wait/time Milliseconds spent waiting for a segment to be scanned. id, segment several hundred milliseconds
segment/scan/pending Number of segments in queue waiting to be scanned. Close to 0
segment/scan/active Number of segments currently scanned. This metric also indicates how many threads from druid.processing.numThreads are currently being used. Close to druid.processing.numThreads
query/cpu/time Microseconds of CPU time taken to complete a query.

Common: dataSource, type, interval, hasFilters, duration, context, remoteAddress, id.

Aggregation Queries: numMetrics, numComplexMetrics.

GroupBy: numDimensions.

TopN: threshold, dimension.

Varies
query/count Number of total queries. This metric is only available if the QueryCountStatsMonitor module is included.
query/success/count Number of queries successfully processed. This metric is only available if the QueryCountStatsMonitor module is included.
query/failed/count Number of failed queries. This metric is only available if the QueryCountStatsMonitor module is included.
query/interrupted/count Number of queries interrupted due to cancellation. This metric is only available if the QueryCountStatsMonitor module is included.
query/timeout/count Number of timed out queries. This metric is only available if the QueryCountStatsMonitor module is included.

Jetty

Metric Description Normal value
jetty/numOpenConnections Number of open jetty connections. Not much higher than number of jetty threads.
jetty/threadPool/total Number of total workable threads allocated. The number should equal to threadPoolNumIdleThreads + threadPoolNumBusyThreads.
jetty/threadPool/idle Number of idle threads. Less than or equal to threadPoolNumTotalThreads. Non zero number means there is less work to do than configured capacity.
jetty/threadPool/busy Number of busy threads that has work to do from the worker queue. Less than or equal to threadPoolNumTotalThreads.
jetty/threadPool/isLowOnThreads A rough indicator of whether number of total workable threads allocated is enough to handle the works in the work queue. 0
jetty/threadPool/min Number of minimum threads allocatable. druid.server.http.numThreads plus a small fixed number of threads allocated for Jetty acceptors and selectors.
jetty/threadPool/max Number of maximum threads allocatable. druid.server.http.numThreads plus a small fixed number of threads allocated for Jetty acceptors and selectors.
jetty/threadPool/queueSize Size of the worker queue. Not much higher than druid.server.http.queueSize.

Cache

Metric Description Dimensions Normal value
query/cache/delta/* Cache metrics since the last emission. N/A
query/cache/total/* Total cache metrics. N/A
*/numEntries Number of cache entries. Varies
*/sizeBytes Size in bytes of cache entries. Varies
*/hits Number of cache hits. Varies
*/misses Number of cache misses. Varies
*/evictions Number of cache evictions. Varies
*/hitRate Cache hit rate. ~40%
*/averageByte Average cache entry byte size. Varies
*/timeouts Number of cache timeouts. 0
*/errors Number of cache errors. 0
*/put/ok Number of new cache entries successfully cached. Varies, but more than zero
*/put/error Number of new cache entries that could not be cached due to errors. Varies, but more than zero
*/put/oversized Number of potential new cache entries that were skipped due to being too large (based on druid.{broker,historical,realtime}.cache.maxEntrySize properties). Varies

Memcached only metrics

Memcached client metrics are reported as per the following. These metrics come directly from the client as opposed to from the cache retrieval layer.

Metric Description Dimensions Normal value
query/cache/memcached/total Cache metrics unique to memcached (only if druid.cache.type=memcached) as their actual values. Variable N/A
query/cache/memcached/delta Cache metrics unique to memcached (only if druid.cache.type=memcached) as their delta from the prior event emission. Variable N/A

SQL Metrics

If SQL is enabled, the Broker will emit the following metrics for SQL.

Metric Description Dimensions Normal value
sqlQuery/time Milliseconds taken to complete a SQL. id, nativeQueryIds, dataSource, remoteAddress, success < 1s
sqlQuery/planningTimeMs Milliseconds taken to plan a SQL to native query. id, nativeQueryIds, dataSource, remoteAddress, success
sqlQuery/bytes number of bytes returned in SQL response. id, nativeQueryIds, dataSource, remoteAddress, success

Ingestion metrics

General native ingestion metrics

Metric Description Dimensions Normal value
ingest/count Count of 1 every time an ingestion job runs (includes compaction jobs). Aggregate using dimensions. dataSource, taskId, taskType, groupId, taskIngestionMode, tags Always 1.
ingest/segments/count Count of final segments created by job (includes tombstones). dataSource, taskId, taskType, groupId, taskIngestionMode, tags At least 1.
ingest/tombstones/count Count of tombstones created by job. dataSource, taskId, taskType, groupId, taskIngestionMode, tags Zero or more for replace. Always zero for non-replace tasks (always zero for legacy replace, see below).

The taskIngestionMode dimension includes the following modes:

  • APPEND: a native ingestion job appending to existing segments
  • REPLACE_LEGACY: the original replace before tombstones
  • REPLACE: a native ingestion job replacing existing segments using tombstones

The mode is decided using the values of the isAppendToExisting and isDropExisting flags in the task's IOConfig as follows:

isAppendToExisting isDropExisting Mode
true false APPEND
true true Invalid combination, exception thrown.
false false REPLACE_LEGACY. The default for JSON-based batch ingestion.
false true REPLACE

The tags dimension is reported only for metrics emitted from ingestion tasks whose ingest spec specifies the tags field in the context field of the ingestion spec. tags is expected to be a map of string to object.

Ingestion metrics for Kafka

These metrics apply to the Kafka indexing service.

Metric Description Dimensions Normal value
ingest/kafka/lag Total lag between the offsets consumed by the Kafka indexing tasks and latest offsets in Kafka brokers across all partitions. Minimum emission period for this metric is a minute. dataSource, stream, tags Greater than 0, should not be a very high number.
ingest/kafka/maxLag Max lag between the offsets consumed by the Kafka indexing tasks and latest offsets in Kafka brokers across all partitions. Minimum emission period for this metric is a minute. dataSource, stream, tags Greater than 0, should not be a very high number.
ingest/kafka/avgLag Average lag between the offsets consumed by the Kafka indexing tasks and latest offsets in Kafka brokers across all partitions. Minimum emission period for this metric is a minute. dataSource, stream, tags Greater than 0, should not be a very high number.
ingest/kafka/partitionLag Partition-wise lag between the offsets consumed by the Kafka indexing tasks and latest offsets in Kafka brokers. Minimum emission period for this metric is a minute. dataSource, stream, partition, tags Greater than 0, should not be a very high number.

Ingestion metrics for Kinesis

These metrics apply to the Kinesis indexing service.

Metric Description Dimensions Normal value
ingest/kinesis/lag/time Total lag time in milliseconds between the current message sequence number consumed by the Kinesis indexing tasks and latest sequence number in Kinesis across all shards. Minimum emission period for this metric is a minute. dataSource, stream, tags Greater than 0, up to max Kinesis retention period in milliseconds.
ingest/kinesis/maxLag/time Max lag time in milliseconds between the current message sequence number consumed by the Kinesis indexing tasks and latest sequence number in Kinesis across all shards. Minimum emission period for this metric is a minute. dataSource, stream, tags Greater than 0, up to max Kinesis retention period in milliseconds.
ingest/kinesis/avgLag/time Average lag time in milliseconds between the current message sequence number consumed by the Kinesis indexing tasks and latest sequence number in Kinesis across all shards. Minimum emission period for this metric is a minute. dataSource, stream, tags Greater than 0, up to max Kinesis retention period in milliseconds.
ingest/kinesis/partitionLag/time Partition-wise lag time in milliseconds between the current message sequence number consumed by the Kinesis indexing tasks and latest sequence number in Kinesis. Minimum emission period for this metric is a minute. dataSource, stream, partition, tags Greater than 0, up to max Kinesis retention period in milliseconds.

Compaction metrics

Compaction tasks emit the following metrics.

Metric Description Dimensions Normal value
compact/segmentAnalyzer/fetchAndProcessMillis Time taken to fetch and process segments to infer the schema for the compaction task to run. dataSource, taskId, taskType, groupId,tags Varies. A high value indicates compaction tasks will speed up from explicitly setting the data schema.

Other ingestion metrics

Streaming ingestion tasks and certain types of batch ingestion emit the following metrics. These metrics are deltas for each emission period.

Metric Description Dimensions Normal value
ingest/events/processed Number of events processed per emission period. dataSource, taskId, taskType, groupId, tags Equal to the number of events per emission period.
ingest/events/processedWithError Number of events processed with some partial errors per emission period. Events processed with partial errors are counted towards both this metric and ingest/events/processed. dataSource, taskId, taskType, groupId, tags 0
ingest/events/unparseable Number of events rejected because the events are unparseable. dataSource, taskId, taskType, groupId, tags 0
ingest/events/thrownAway Number of events rejected because they are null, or filtered by transformSpec, or outside one of lateMessageRejectionPeriod, earlyMessageRejectionPeriod, or windowPeriod. dataSource, taskId, taskType, groupId, tags 0
ingest/events/duplicate Number of events rejected because the events are duplicated. dataSource, taskId, taskType, groupId, tags 0
ingest/input/bytes Number of bytes read from input sources, after decompression but prior to parsing. This covers all data read, including data that does not end up being fully processed and ingested. For example, this includes data that ends up being rejected for being unparseable or filtered out. dataSource, taskId, taskType, groupId, tags Depends on the amount of data read.
ingest/rows/output Number of Druid rows persisted. dataSource, taskId, taskType, groupId Your number of events with rollup.
ingest/persists/count Number of times persist occurred. dataSource, taskId, taskType, groupId, tags Depends on the configuration.
ingest/persists/time Milliseconds spent doing intermediate persist. dataSource, taskId, taskType, groupId, tags Depends on the configuration. Generally a few minutes at most.
ingest/persists/cpu CPU time in nanoseconds spent on doing intermediate persist. dataSource, taskId, taskType, groupId, tags Depends on the configuration. Generally a few minutes at most.
ingest/persists/backPressure Milliseconds spent creating persist tasks and blocking waiting for them to finish. dataSource, taskId, taskType, groupId, tags 0 or very low
ingest/persists/failed Number of persists that failed. dataSource, taskId, taskType, groupId, tags 0
ingest/handoff/failed Number of handoffs that failed. dataSource, taskId, taskType, groupId,tags 0
ingest/merge/time Milliseconds spent merging intermediate segments. dataSource, taskId, taskType, groupId, tags Depends on the configuration. Generally a few minutes at most.
ingest/merge/cpu CPU time in Nanoseconds spent on merging intermediate segments. dataSource, taskId, taskType, groupId, tags Depends on the configuration. Generally a few minutes at most.
ingest/handoff/count Number of handoffs that happened. dataSource, taskId, taskType, groupId, tags Varies. Generally greater than 0 once every segment granular period if cluster operating normally.
ingest/sink/count Number of sinks not handed off. dataSource, taskId, taskType, groupId, tags 1~3
ingest/events/messageGap Time gap in milliseconds between the latest ingested event timestamp and the current system timestamp of metrics emission. If the value is increasing but lag is low, Druid may not be receiving new data. This metric is reset as new tasks spawn up. dataSource, taskId, taskType, groupId, tags Greater than 0, depends on the time carried in event.
ingest/notices/queueSize Number of pending notices to be processed by the coordinator. dataSource, tags Typically 0 and occasionally in lower single digits. Should not be a very high number.
ingest/notices/time Milliseconds taken to process a notice by the supervisor. dataSource, tags < 1s
ingest/pause/time Milliseconds spent by a task in a paused state without ingesting. dataSource, taskId, tags < 10 seconds
ingest/handoff/time Total number of milliseconds taken to handoff a set of segments. dataSource, taskId, taskType, groupId, tags Depends on the coordinator cycle time.

If the JVM does not support CPU time measurement for the current thread, ingest/merge/cpu and ingest/persists/cpu will be 0.

Indexing service

Metric Description Dimensions Normal value
task/run/time Milliseconds taken to run a task. dataSource, taskId, taskType, groupId, taskStatus, tags Varies
task/pending/time Milliseconds taken for a task to wait for running. dataSource, taskId, taskType, groupId, tags Varies
task/action/log/time Milliseconds taken to log a task action to the audit log. dataSource, taskId, taskType, groupId, taskActionType, tags < 1000 (subsecond)
task/action/run/time Milliseconds taken to execute a task action. dataSource, taskId, taskType, groupId, taskActionType, tags Varies from subsecond to a few seconds, based on action type.
task/action/success/count Number of task actions that were executed successfully during the emission period. Currently only being emitted for batched segmentAllocate actions. dataSource, taskId, taskType, groupId, taskActionType, tags Varies
task/action/failed/count Number of task actions that failed during the emission period. Currently only being emitted for batched segmentAllocate actions. dataSource, taskId, taskType, groupId, taskActionType, tags Varies
task/action/batch/queueTime Milliseconds spent by a batch of task actions in queue. Currently only being emitted for batched segmentAllocate actions. dataSource, taskActionType, interval Varies based on the batchAllocationWaitTime and number of batches in queue.
task/action/batch/runTime Milliseconds taken to execute a batch of task actions. Currently only being emitted for batched segmentAllocate actions. dataSource, taskActionType, interval Varies from subsecond to a few seconds, based on action type and batch size.
task/action/batch/size Number of task actions in a batch that was executed during the emission period. Currently only being emitted for batched segmentAllocate actions. dataSource, taskActionType, interval Varies based on number of concurrent task actions.
task/action/batch/attempts Number of execution attempts for a single batch of task actions. Currently only being emitted for batched segmentAllocate actions. dataSource, taskActionType, interval 1 if there are no failures or retries.
task/segmentAvailability/wait/time The amount of milliseconds a batch indexing task waited for newly created segments to become available for querying. dataSource, taskType, groupId, taskId, segmentAvailabilityConfirmed, tags Varies
segment/added/bytes Size in bytes of new segments created. dataSource, taskId, taskType, groupId, interval, tags Varies
segment/moved/bytes Size in bytes of segments moved/archived via the Move Task. dataSource, taskId, taskType, groupId, interval, tags Varies
segment/nuked/bytes Size in bytes of segments deleted via the Kill Task. dataSource, taskId, taskType, groupId, interval, tags Varies
task/success/count Number of successful tasks per emission period. This metric is only available if the TaskCountStatsMonitor module is included. dataSource Varies
task/failed/count Number of failed tasks per emission period. This metric is only available if the TaskCountStatsMonitor module is included. dataSource Varies
task/running/count Number of current running tasks. This metric is only available if the TaskCountStatsMonitor module is included. dataSource Varies
task/pending/count Number of current pending tasks. This metric is only available if the TaskCountStatsMonitor module is included. dataSource Varies
task/waiting/count Number of current waiting tasks. This metric is only available if the TaskCountStatsMonitor module is included. dataSource Varies
taskSlot/total/count Number of total task slots per emission period. This metric is only available if the TaskSlotCountStatsMonitor module is included. category Varies
taskSlot/idle/count Number of idle task slots per emission period. This metric is only available if the TaskSlotCountStatsMonitor module is included. category Varies
taskSlot/used/count Number of busy task slots per emission period. This metric is only available if the TaskSlotCountStatsMonitor module is included. category Varies
taskSlot/lazy/count Number of total task slots in lazy marked Middle Managers and Indexers per emission period. This metric is only available if the TaskSlotCountStatsMonitor module is included. category Varies
taskSlot/blacklisted/count Number of total task slots in blacklisted Middle Managers and Indexers per emission period. This metric is only available if the TaskSlotCountStatsMonitor module is included. category Varies
worker/task/failed/count Number of failed tasks run on the reporting worker per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included, and is only supported for Middle Manager nodes. category, workerVersion Varies
worker/task/success/count Number of successful tasks run on the reporting worker per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included, and is only supported for Middle Manager nodes. category,workerVersion Varies
worker/taskSlot/idle/count Number of idle task slots on the reporting worker per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included, and is only supported for Middle Manager nodes. category, workerVersion Varies
worker/taskSlot/total/count Number of total task slots on the reporting worker per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included. category, workerVersion Varies
worker/taskSlot/used/count Number of busy task slots on the reporting worker per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included. category, workerVersion Varies

Shuffle metrics (Native parallel task)

The shuffle metrics can be enabled by adding org.apache.druid.indexing.worker.shuffle.ShuffleMonitor in druid.monitoring.monitors. See Enabling metrics for more details.

Metric Description Dimensions Normal value
ingest/shuffle/bytes Number of bytes shuffled per emission period. supervisorTaskId Varies
ingest/shuffle/requests Number of shuffle requests per emission period. supervisorTaskId Varies

Coordination

These metrics are for the Druid Coordinator and are reset each time the Coordinator runs the coordination logic.

Metric Description Dimensions Normal value
segment/assigned/count Number of segments assigned to be loaded in the cluster. dataSource, tier Varies
segment/moved/count Number of segments moved in the cluster. dataSource, tier Varies
segment/dropped/count Number of segments chosen to be dropped from the cluster due to being over-replicated. dataSource, tier Varies
segment/deleted/count Number of segments marked as unused due to drop rules. dataSource Varies
segment/unneeded/count Number of segments dropped due to being marked as unused. dataSource, tier Varies
segment/assignSkipped/count Number of segments that could not be assigned to any server for loading. This can occur due to replication throttling, no available disk space, or a full load queue. dataSource, tier, description Varies
segment/moveSkipped/count Number of segments that were chosen for balancing but could not be moved. This can occur when segments are already optimally placed. dataSource, tier, description Varies
segment/dropSkipped/count Number of segments that could not be dropped from any server. dataSource, tier, description Varies
segment/loadQueue/size Size in bytes of segments to load. server Varies
segment/loadQueue/count Number of segments to load. server Varies
segment/dropQueue/count Number of segments to drop. server Varies
segment/loadQueue/assigned Number of segments assigned for load or drop to the load queue of a server. dataSource, server Varies
segment/loadQueue/success Number of segment assignments that completed successfully. dataSource, server Varies
segment/loadQueue/failed Number of segment assignments that failed to complete. dataSource, server 0
segment/loadQueue/cancelled Number of segment assignments that were canceled before completion. dataSource, server Varies
segment/size Total size of used segments in a data source. Emitted only for data sources to which at least one used segment belongs. dataSource Varies
segment/count Number of used segments belonging to a data source. Emitted only for data sources to which at least one used segment belongs. dataSource < max
segment/overShadowed/count Number of segments marked as unused due to being overshadowed. Varies
segment/unavailable/count Number of unique segments left to load until all used segments are available for queries. dataSource 0
segment/underReplicated/count Number of segments, including replicas, left to load until all used segments are available for queries. tier, dataSource 0
tier/historical/count Number of available historical nodes in each tier. tier Varies
tier/replication/factor Configured maximum replication factor in each tier. tier Varies
tier/required/capacity Total capacity in bytes required in each tier. tier Varies
tier/total/capacity Total capacity in bytes available in each tier. tier Varies
compact/task/count Number of tasks issued in the auto compaction run. Varies
compactTask/maxSlot/count Maximum number of task slots available for auto compaction tasks in the auto compaction run. Varies
compactTask/availableSlot/count Number of available task slots that can be used for auto compaction tasks in the auto compaction run. This is the max number of task slots minus any currently running compaction tasks. Varies
killTask/availableSlot/count Number of available task slots that can be used for auto kill tasks in the auto kill run. This is the max number of task slots minus any currently running auto kill tasks. Varies
killTask/maxSlot/count Maximum number of task slots available for auto kill tasks in the auto kill run. Varies
kill/task/count Number of tasks issued in the auto kill run. Varies
kill/pendingSegments/count Number of stale pending segments deleted from the metadata store. dataSource Varies
segment/waitCompact/bytes Total bytes of this datasource waiting to be compacted by the auto compaction (only consider intervals/segments that are eligible for auto compaction). dataSource Varies
segment/waitCompact/count Total number of segments of this datasource waiting to be compacted by the auto compaction (only consider intervals/segments that are eligible for auto compaction). dataSource Varies
interval/waitCompact/count Total number of intervals of this datasource waiting to be compacted by the auto compaction (only consider intervals/segments that are eligible for auto compaction). dataSource Varies
segment/compacted/bytes Total bytes of this datasource that are already compacted with the spec set in the auto compaction config. dataSource Varies
segment/compacted/count Total number of segments of this datasource that are already compacted with the spec set in the auto compaction config. dataSource Varies
interval/compacted/count Total number of intervals of this datasource that are already compacted with the spec set in the auto compaction config. dataSource Varies
segment/skipCompact/bytes Total bytes of this datasource that are skipped (not eligible for auto compaction) by the auto compaction. dataSource Varies
segment/skipCompact/count Total number of segments of this datasource that are skipped (not eligible for auto compaction) by the auto compaction. dataSource Varies
interval/skipCompact/count Total number of intervals of this datasource that are skipped (not eligible for auto compaction) by the auto compaction. dataSource Varies
coordinator/time Approximate Coordinator duty runtime in milliseconds. duty Varies
coordinator/global/time Approximate runtime of a full coordination cycle in milliseconds. The dutyGroup dimension indicates what type of coordination this run was. For example: Historical Management or Indexing. dutyGroup Varies
metadata/kill/supervisor/count Total number of terminated supervisors that were automatically deleted from metadata store per each Coordinator kill supervisor duty run. This metric can help adjust druid.coordinator.kill.supervisor.durationToRetain configuration based on whether more or less terminated supervisors need to be deleted per cycle. This metric is only emitted when druid.coordinator.kill.supervisor.on is set to true. Varies
metadata/kill/audit/count Total number of audit logs that were automatically deleted from metadata store per each Coordinator kill audit duty run. This metric can help adjust druid.coordinator.kill.audit.durationToRetain configuration based on whether more or less audit logs need to be deleted per cycle. This metric is emitted only when druid.coordinator.kill.audit.on is set to true. Varies
metadata/kill/compaction/count Total number of compaction configurations that were automatically deleted from metadata store per each Coordinator kill compaction configuration duty run. This metric is only emitted when druid.coordinator.kill.compaction.on is set to true. Varies
metadata/kill/rule/count Total number of rules that were automatically deleted from metadata store per each Coordinator kill rule duty run. This metric can help adjust druid.coordinator.kill.rule.durationToRetain configuration based on whether more or less rules need to be deleted per cycle. This metric is only emitted when druid.coordinator.kill.rule.on is set to true. Varies
metadata/kill/datasource/count Total number of datasource metadata that were automatically deleted from metadata store per each Coordinator kill datasource duty run. Note that datasource metadata only exists for datasource created from supervisor. This metric can help adjust druid.coordinator.kill.datasource.durationToRetain configuration based on whether more or less datasource metadata need to be deleted per cycle. This metric is only emitted when druid.coordinator.kill.datasource.on is set to true. Varies
serverview/init/time Time taken to initialize the coordinator server view. Depends on the number of segments.
serverview/sync/healthy Sync status of the Coordinator with a segment-loading server such as a Historical or Peon. Emitted only when HTTP-based server view is enabled. You can use this metric in conjunction with serverview/sync/unstableTime to debug slow startup of the Coordinator. server, tier 1 for fully synced servers, 0 otherwise
serverview/sync/unstableTime Time in milliseconds for which the Coordinator has been failing to sync with a segment-loading server. Emitted only when HTTP-based server view is enabled. server, tier Not emitted for synced servers.

General Health

Service Health

Metric Description Dimensions Normal value
service/heartbeat Metric indicating the service is up. ServiceStatusMonitor must be enabled. leader on the Overlord and Coordinator.
workerVersion, category, status on the Middle Manager.
taskId, groupId, taskType, dataSource on the Peon
1

Historical

Metric Description Dimensions Normal value
segment/max Maximum byte limit available for segments. Varies.
segment/used Bytes used for served segments. dataSource, tier, priority < max
segment/usedPercent Percentage of space used by served segments. dataSource, tier, priority < 100%
segment/count Number of served segments. dataSource, tier, priority Varies
segment/pendingDelete On-disk size in bytes of segments that are waiting to be cleared out. Varies
segment/rowCount/avg The average number of rows per segment on a historical. SegmentStatsMonitor must be enabled. dataSource, tier, priority Varies. See segment optimization for guidance on optimal segment sizes.
segment/rowCount/range/count The number of segments in a bucket. SegmentStatsMonitor must be enabled. dataSource, tier, priority, range Varies

JVM

These metrics are only available if the JvmMonitor module is included in druid.monitoring.monitors. For more information, see Enabling Metrics.

Metric Description Dimensions Normal value
jvm/pool/committed Committed pool poolKind, poolName Close to max pool
jvm/pool/init Initial pool poolKind, poolName Varies
jvm/pool/max Max pool poolKind, poolName Varies
jvm/pool/used Pool used poolKind, poolName < max pool
jvm/bufferpool/count Bufferpool count bufferpoolName Varies
jvm/bufferpool/used Bufferpool used bufferpoolName Close to capacity
jvm/bufferpool/capacity Bufferpool capacity bufferpoolName Varies
jvm/mem/init Initial memory memKind Varies
jvm/mem/max Max memory memKind Varies
jvm/mem/used Used memory memKind < max memory
jvm/mem/committed Committed memory memKind Close to max memory
jvm/gc/count Garbage collection count gcName (cms/g1/parallel/etc.), gcGen (old/young) Varies
jvm/gc/cpu Count of CPU time in Nanoseconds spent on garbage collection. Note: jvm/gc/cpu represents the total time over multiple GC cycles; divide by jvm/gc/count to get the mean GC time per cycle. gcName, gcGen Sum of jvm/gc/cpu should be within 10-30% of sum of jvm/cpu/total, depending on the GC algorithm used (reported by JvmCpuMonitor).

ZooKeeper

These metrics are available only when druid.zk.service.enabled = true.

Metric Description Dimensions Normal value
zk/connected Indicator of connection status. 1 for connected, 0 for disconnected. Emitted once per monitor period. None 1
zk/reconnect/time Amount of time, in milliseconds, that a server was disconnected from ZooKeeper before reconnecting. Emitted on reconnection. Not emitted if connection to ZooKeeper is permanently lost, because in this case, there is no reconnection. None Not present

EventReceiverFirehose

The following metric is only available if the EventReceiverFirehoseMonitor module is included.

Metric Description Dimensions Normal value
ingest/events/buffered Number of events queued in the EventReceiverFirehose buffer. serviceName, dataSource, taskId, taskType, bufferCapacity Equal to the current number of events in the buffer queue.
ingest/bytes/received Number of bytes received by the EventReceiverFirehose. serviceName, dataSource, taskId, taskType Varies

Sys [Deprecated]

SysMonitor is now deprecated and will be removed in future releases. Instead, use the new OSHI monitor called OshiSysMonitor. The new monitor has a wider support for different machine architectures including ARM instances.

These metrics are only available if the SysMonitor module is included.

Metric Description Dimensions Normal value
sys/swap/free Free swap Varies
sys/swap/max Max swap Varies
sys/swap/pageIn Paged in swap Varies
sys/swap/pageOut Paged out swap Varies
sys/disk/write/count Writes to disk fsDevName, fsDirName, fsTypeName, fsSysTypeName, fsOptions Varies
sys/disk/read/count Reads from disk fsDevName, fsDirName, fsTypeName, fsSysTypeName, fsOptions Varies
sys/disk/write/size Bytes written to disk. One indicator of the amount of paging occurring for segments. fsDevName,fsDirName,fsTypeName, fsSysTypeName, fsOptions Varies
sys/disk/read/size Bytes read from disk. One indicator of the amount of paging occurring for segments. fsDevName,fsDirName, fsTypeName, fsSysTypeName, fsOptions Varies
sys/net/write/size Bytes written to the network netName, netAddress, netHwaddr Varies
sys/net/read/size Bytes read from the network netName, netAddress, netHwaddr Varies
sys/fs/used Filesystem bytes used fsDevName, fsDirName, fsTypeName, fsSysTypeName, fsOptions < max
sys/fs/max Filesystem bytes max fsDevName, fsDirName, fsTypeName, fsSysTypeName, fsOptions Varies
sys/mem/used Memory used < max
sys/mem/max Memory max Varies
sys/storage/used Disk space used fsDirName Varies
sys/cpu CPU used cpuName, cpuTime Varies

OshiSysMonitor

These metrics are only available if the OshiSysMonitor module is included.

Metric Description Dimensions Normal Value
sys/swap/free Free swap Varies
sys/swap/max Max swap Varies
sys/swap/pageIn Paged in swap Varies
sys/swap/pageOut Paged out swap Varies
sys/disk/write/count Writes to disk diskName Varies
sys/disk/read/count Reads from disk diskName Varies
sys/disk/write/size Bytes written to disk. One indicator of the amount of paging occurring for segments. diskName Varies
sys/disk/read/size Bytes read from disk. One indicator of the amount of paging occurring for segments. diskName Varies
sys/disk/queue Disk queue length. Measures number of requests waiting to be processed by disk diskName Generally 0
sys/disk/transferTime Transfer time to read from or write to disk diskName Depends on hardware
sys/net/write/size Bytes written to the network netName, netAddress, netHwaddr Varies
sys/net/read/size Bytes read from the network netName, netAddress, netHwaddr Varies
sys/net/read/packets Total packets read from the network netName, netAddress, netHwaddr Varies
sys/net/write/packets Total packets written to the network netName, netAddress, netHwaddr Varies
sys/net/read/errors Total network read errors netName, netAddress, netHwaddr Generally 0
sys/net/write/errors Total network write errors netName, netAddress, netHwaddr Generally 0
sys/net/read/dropped Total packets dropped coming from network netName, netAddress, netHwaddr Generally 0
sys/net/write/collisions Total network write collisions netName, netAddress, netHwaddr Generally 0
sys/fs/used Filesystem bytes used fsDevName, fsDirName < max
sys/fs/max Filesystem bytes max fsDevName, fsDirName Varies
sys/fs/files/count Filesystem total IO nodes fsDevName, fsDirName < max
sys/fs/files/free Filesystem free IO nodes fsDevName, fsDirName Varies
sys/mem/used Memory used < max
sys/mem/max Memory max Varies
sys/mem/free Memory free Varies
sys/storage/used Disk space used fsDirName Varies
sys/cpu CPU used cpuName, cpuTime Varies
sys/uptime Total system uptime Varies
sys/la/{i} System CPU load averages over past i minutes, where i={1,5,15} Varies
sys/tcpv4/activeOpens Total TCP active open connections Varies
sys/tcpv4/passiveOpens Total TCP passive open connections Varies
sys/tcpv4/attemptFails Total TCP active connection failures Generally 0
sys/tcpv4/estabResets Total TCP connection resets Generally 0
sys/tcpv4/in/segs Total segments received in connection Varies
sys/tcpv4/in/errs Errors while reading segments Generally 0
sys/tcpv4/out/segs Total segments sent Varies
sys/tcpv4/out/rsts Total "out reset" packets sent to reset the connection Generally 0
sys/tcpv4/retrans/segs Total segments re-transmitted Varies

Cgroup

These metrics are available on operating systems with the cgroup kernel feature. All the values are derived by reading from /sys/fs/cgroup.

Metric Description Dimensions Normal value
cgroup/cpu/shares Relative value of CPU time available to this process. Read from cpu.shares. Varies
cgroup/cpu/cores_quota Number of cores available to this process. Derived from cpu.cfs_quota_us/cpu.cfs_period_us. Varies. A value of -1 indicates there is no explicit quota set.
cgroup/memory/* Memory stats for this process, such as cache and total_swap. Each stat produces a separate metric. Read from memory.stat. Varies
cgroup/memory_numa/*/pages Memory stats, per NUMA node, for this process, such as total and unevictable. Each stat produces a separate metric. Read from memory.num_stat. numaZone Varies
cgroup/cpuset/cpu_count Total number of CPUs available to the process. Derived from cpuset.cpus. Varies
cgroup/cpuset/effective_cpu_count Total number of active CPUs available to the process. Derived from cpuset.effective_cpus. Varies
cgroup/cpuset/mems_count Total number of memory nodes available to the process. Derived from cpuset.mems. Varies
cgroup/cpuset/effective_mems_count Total number of active memory nodes available to the process. Derived from cpuset.effective_mems. Varies