Most metric values reset each emission period. By default druid emission period is 1 minute, this can be changed by setting the property `druid.monitoring.emissionPeriod`.
|`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/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 or timeout|This metric is only available if the QueryCountStatsMonitor module is included.||
|`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.|several hundred milliseconds|
|`query/wait/time`|Milliseconds spent waiting for a segment to be scanned.|id, segment.|<severalhundredmilliseconds|
|`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/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 or timeout|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 or timeout|This metric is only available if the QueryCountStatsMonitor module is included.||
|`*/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.|
|`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|
These metrics are applicable for 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.|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.|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.|Greater than 0, should not be a very high number |
These metrics are only available if the RealtimeMetricsMonitor is included in the monitors list for the Realtime process. These metrics are deltas for each emission period.
|`ingest/events/processed`|Number of events successfully processed per emission period.|dataSource, taskId, taskType.|Equal to your # of events per emission period.|
|`ingest/rows/output`|Number of Druid rows persisted.|dataSource, taskId, taskType.|Your # 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 between the data time in event and current system time.|dataSource, taskId, taskType.|Greater than 0, depends on the time carried in event |
|`task/run/time`|Milliseconds taken to run a task.|dataSource, taskId, taskType, taskStatus.|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.|
|`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|
If `emitBalancingStats` is set to `true` in the Coordinator [dynamic configuration](../configuration/index.html#dynamic-configuration), then [log entries](../configuration/logging.md) for class `org.apache.druid.server.coordinator.helper.DruidCoordinatorLogger` will have extra information on balancing decisions.
|`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`](../configuration/index.html#enabling-metrics)) |
|`ingest/events/buffered`|Number of events queued in the EventReceiverFirehose's buffer|serviceName, dataSource, taskId, taskType, bufferCapacity.|Equal to current # of events in the buffer queue.|
|`sys/disk/write/size`|Bytes written to disk. Can we used to determine how much paging is occurring with regards to segments.|fsDevName, fsDirName, fsTypeName, fsSysTypeName, fsOptions.|Varies.|
|`sys/disk/read/size`|Bytes read from disk. Can we used to determine how much paging is occurring with regards to segments.|fsDevName, fsDirName, fsTypeName, fsSysTypeName, fsOptions.|Varies.|
