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.

:::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
metadatacache/schemaPoll/count	Number of coordinator polls to fetch datasource schema.
metadatacache/schemaPoll/failed	Number of failed coordinator polls to fetch datasource schema.
metadatacache/schemaPoll/time	Time taken for coordinator polls to fetch datasource schema.
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.
task/autoScaler/requiredCount	Count of required tasks based on the calculations of lagBased auto scaler.	dataSource, stream, scalingSkipReason	Depends on auto scaler config.

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
worker/task/assigned/count	Number of tasks assigned to an indexer per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included.	dataSource	Varies
worker/task/completed/count	Number of tasks completed by an indexer per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included.	dataSource	Varies
worker/task/running/count	Number of tasks running on an indexer per emission period. This metric is only available if the WorkerTaskCountStatsMonitor module is included.	dataSource	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/unneededEternityTombstone/count	Number of non-overshadowed eternity tombstones marked as unused.		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
segment/availableDeepStorageOnly/count	Number of unique segments that are only available for querying directly from deep storage.	dataSource	Varies
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/eligibleUnusedSegments/count	The number of unused segments of a datasource that are identified as eligible for deletion from the metadata store by the coordinator.	dataSource	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.
metadatacache/init/time	Time taken to initialize the coordinator segment metadata cache.		Depends on the number of segments.
metadatacache/refresh/count	Number of segments to refresh in coordinator segment metadata cache.	dataSource
metadatacache/refresh/time	Time taken to refresh segments in coordinator segment metadata cache.	dataSource
metadatacache/backfill/count	Number of segments for which schema was back filled in the database.	dataSource
metadatacache/realtimeSegmentSchema/count	Number of realtime segments for which schema is cached.		Depends on the number of realtime segments in the cluster.
metadatacache/finalizedSegmentMetadata/count	Number of finalized segments for which schema metadata is cached.		Depends on the number of segments in the cluster.
metadatacache/finalizedSchemaPayload/count	Number of finalized segment schema cached.		Depends on the number of distinct schema in the cluster.
metadatacache/temporaryMetadataQueryResults/count	Number of segments for which schema was fetched by executing segment metadata query.		Eventually it should be 0.
metadatacache/temporaryPublishedMetadataQueryResults/count	Number of segments for which schema is cached after back filling in the database.		This value gets reset after each database poll. Eventually it should be 0.

General Health

Service Health

Metric	Description	Dimensions	Normal value
service/heartbeat	Metric indicating the service is up. This metric is emitted only when ServiceStatusMonitor is enabled.	leader on the Overlord and Coordinator. workerVersion, category, status on the Middle Manager. taskId, groupId, taskType, dataSource, tags 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, jvmVersion	Close to max pool
jvm/pool/init	Initial pool	poolKind, poolName, jvmVersion	Varies
jvm/pool/max	Max pool	poolKind, poolName, jvmVersion	Varies
jvm/pool/used	Pool used	poolKind, poolName, jvmVersion	< max pool
jvm/bufferpool/count	Bufferpool count	bufferpoolName, jvmVersion	Varies
jvm/bufferpool/used	Bufferpool used	bufferpoolName, jvmVersion	Close to capacity
jvm/bufferpool/capacity	Bufferpool capacity	bufferpoolName, jvmVersion	Varies
jvm/mem/init	Initial memory	memKind, jvmVersion	Varies
jvm/mem/max	Max memory	memKind, jvmVersion	Varies
jvm/mem/used	Used memory	memKind, jvmVersion	< max memory
jvm/mem/committed	Committed memory	memKind, jvmVersion	Close to max memory
jvm/gc/count	Garbage collection count	gcName (cms/g1/parallel/etc.), gcGen (old/young), jvmVersion	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, jvmVersion	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/cpu/usage/total/percentage	Total cpu percentage used by cgroup of process that is running		0-100
cgroup/cpu/usage/user/percentage	User cpu percentage used by cgroup of process that is running		0-100
cgroup/cpu/usage/sys/percentage	Sys cpu percentage used by cgroup of process that is running		0-100
cgroup/disk/read/size	Reports the number of bytes transferred to specific devices by a cgroup of process that is running.	diskName	Varies
cgroup/disk/write/size	Reports the number of bytes transferred from specific devices by a cgroup of process that is running.	diskName	Varies
cgroup/disk/read/count	Reports the number of read operations performed on specific devices by a cgroup of process that is running.	diskName	Varies
cgroup/disk/write/count	Reports the number of write operations performed on specific devices by a cgroup of process that is running.	diskName	Varies
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/memory/limit/bytes	Reports the maximum memory that can be used by processes in the cgroup (in bytes)		Varies
cgroup/memory/usage/bytes	Reports the maximum amount of user memory (including file cache)		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