druid/docs/operations/metrics.md

id	title
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.

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.
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	< 1s
sqlQuery/planningTimeMs	Milliseconds taken to plan a SQL to native query.	id, nativeQueryIds, dataSource, remoteAddress, success
sqlQuery/bytes	Number of bytes returned in the SQL query response.	id, nativeQueryIds, dataSource, remoteAddress, success

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
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.

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
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, taskIngestionMode	Always 1.
ingest/segments/count	Count of final segments created by job (includes tombstones).	dataSource, taskId, taskType, taskIngestionMode	At least 1.
ingest/tombstones/count	Count of tombstones created by job.	dataSource, taskId, taskType, taskIngestionMode	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 (this is the default for native batch ingestion).
false	true	REPLACE

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	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	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	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	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	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	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	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	Greater than 0, up to max Kinesis retention period in milliseconds.

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/thrownAway	Number of events rejected because they are either null, or filtered by the transform spec, or outside the windowPeriod.	dataSource, taskId, taskType	0
ingest/events/unparseable	Number of events rejected because the events are unparseable.	dataSource, taskId, taskType	0
ingest/events/duplicate	Number of events rejected because the events are duplicated.	dataSource, taskId, taskType	0
ingest/events/processed	Number of events successfully processed per emission period.	dataSource, taskId, taskType	Equal to the number of events per emission period.
ingest/rows/output	Number of Druid rows persisted.	dataSource, taskId, taskType	Your number of events with rollup.
ingest/persists/count	Number of times persist occurred.	dataSource, taskId, taskType	Depends on configuration.
ingest/persists/time	Milliseconds spent doing intermediate persist.	dataSource, taskId, taskType	Depends on configuration. Generally a few minutes at most.
ingest/persists/cpu	Cpu time in Nanoseconds spent on doing intermediate persist.	dataSource, taskId, taskType	Depends on 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	0 or very low
ingest/persists/failed	Number of persists that failed.	dataSource, taskId, taskType	0
ingest/handoff/failed	Number of handoffs that failed.	dataSource, taskId, taskType	0
ingest/merge/time	Milliseconds spent merging intermediate segments.	dataSource, taskId, taskType	Depends on configuration. Generally a few minutes at most.
ingest/merge/cpu	Cpu time in Nanoseconds spent on merging intermediate segments.	dataSource, taskId, taskType	Depends on configuration. Generally a few minutes at most.
ingest/handoff/count	Number of handoffs that happened.	dataSource, taskId, taskType	Varies. Generally greater than 0 once every segment granular period if cluster operating normally.
ingest/sink/count	Number of sinks not handoffed.	dataSource, taskId, taskType	1~3
ingest/events/messageGap	Time gap in milliseconds between the latest ingested event timestamp and the current system timestamp of metrics emission.	dataSource, taskId, taskType	Greater than 0, depends on the time carried in event.
ingest/notices/queueSize	Number of pending notices to be processed by the coordinator.	dataSource	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	< 1s
ingest/pause/time	Milliseconds spent by a task in a paused state without ingesting.	dataSource, taskId	< 10 seconds
ingest/handoff/time	Total time taken for each set of segments handed off.	dataSource, taskId, taskType	Depends on coordinator cycle time.

Note: 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, taskStatus	Varies
task/pending/time	Milliseconds taken for a task to wait for running.	dataSource, taskId, taskType	Varies
task/action/log/time	Milliseconds taken to log a task action to the audit log.	dataSource, taskId, taskType	< 1000 (subsecond)
task/action/run/time	Milliseconds taken to execute a task action.	dataSource, taskId, taskType	Varies from subsecond to a few seconds, based on action type.
segment/added/bytes	Size in bytes of new segments created.	dataSource, taskId, taskType, interval	Varies
segment/moved/bytes	Size in bytes of segments moved/archived via the Move Task.	dataSource, taskId, taskType, interval	Varies
segment/nuked/bytes	Size in bytes of segments deleted via the Kill Task.	dataSource, taskId, taskType, interval	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 MiddleManagers 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 MiddleManagers and Indexers per emission period. This metric is only available if the TaskSlotCountStatsMonitor module is included.	category	Varies
task/segmentAvailability/wait/time	The amount of milliseconds a batch indexing task waited for newly created segments to become available for querying.	dataSource, taskType, taskId, segmentAvailabilityConfirmed	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 middleManager 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 middleManager 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 middleManager 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.	tier	Varies
segment/moved/count	Number of segments moved in the cluster.	tier	Varies
segment/unmoved/count	Number of segments which were chosen for balancing but were found to be already optimally placed.	tier	Varies
segment/dropped/count	Number of segments chosen to be dropped from the cluster due to being over-replicated.	tier	Varies
segment/deleted/count	Number of segments marked as unused due to drop rules.	tier	Varies
segment/unneeded/count	Number of segments dropped due to being marked as unused.	tier	Varies
segment/cost/raw	Used in cost balancing. The raw cost of hosting segments.	tier	Varies
segment/cost/normalization	Used in cost balancing. The normalization of hosting segments.	tier	Varies
segment/cost/normalized	Used in cost balancing. The normalized cost of hosting segments.	tier	Varies
segment/loadQueue/size	Size in bytes of segments to load.	server	Varies
segment/loadQueue/failed	Number of segments that failed to load.	server	0
segment/loadQueue/count	Number of segments to load.	server	Varies
segment/dropQueue/count	Number of segments to drop.	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 segments (not including replicas) left to load until segments that should be loaded in the cluster are available for queries.	dataSource	0
segment/underReplicated/count	Number of segments (including replicas) left to load until segments that should be loaded in the cluster 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	Max number of task slots that can be used 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
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. The duty dimension is the string alias of the Duty that is being run.	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. i.e. Historical Management vs 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. Note that 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. Note that this metric is only emitted 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. Note that 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. Note that 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: 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. Note that this metric is only emitted when druid.coordinator.kill.datasource.on is set to true.		Varies

If emitBalancingStats is set to true in the Coordinator dynamic configuration, then log entries for class org.apache.druid.server.coordinator.duty.EmitClusterStatsAndMetrics will have extra information on balancing decisions.

General Health

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.

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).

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 current number of events in the buffer queue.
ingest/bytes/received	Number of bytes received by the EventReceiverFirehose.	serviceName, dataSource, taskId, taskType	Varies

Sys

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

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 (e.g. cache, total_swap, etc.). Each stat produces a separate metric. Read from memory.stat.		Varies
cgroup/memory_numa/*/pages	Memory stats, per NUMA node, for this process (e.g. total, unevictable, etc.). 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