317brian commented on code in PR #18103: URL: https://github.com/apache/druid/pull/18103#discussion_r2136555991
########## docs/configuration/index.md: ########## @@ -2031,6 +1893,151 @@ See [cache configuration](#cache-configuration) for how to configure cache setti |`druid.broker.segment.watchRealtimeTasks`|Boolean|The Broker watches segment announcements from processes that serve segments to build a cache to relate each process to the segments it serves. When `watchRealtimeTasks` is true, the Broker watches for segment announcements from both Historicals and realtime processes. To configure a broker to exclude segments served by realtime processes, set `watchRealtimeTasks` to false. |true| |`druid.broker.segment.awaitInitializationOnStart`|Boolean|Whether the Broker will wait for its view of segments to fully initialize before starting up. If set to 'true', the Broker's HTTP server will not start up, and the Broker will not announce itself as available, until the server view is initialized. See also `druid.sql.planner.awaitInitializationOnStart`, a related setting.|true| +## Metrics monitors + +You can configure Druid services to emit [metrics](../operations/metrics.md) regularly from a number of [monitors](#metrics-monitors-for-each-service) via [emitters](#metrics-emitters). The following table lists general configurations for metrics: + +|Property|Description|Default| +|--------|-----------|-------| +|`druid.monitoring.emissionPeriod`| Frequency that Druid emits metrics.|`PT1M`| +|[`druid.monitoring.monitors`](#metrics-monitors-for-each-service)|Sets list of Druid monitors used by a service.|none (no monitors)| +|[`druid.emitter`](#metrics-emitters)|Setting this value initializes one of the emitter modules.|`noop` (metric emission disabled by default)| + +### Metrics monitors for each service + +:::caution + +Because each monitor is meant for a specific service or services, make sure you configure them for the correct service unless it is meant for any service. For example, if a monitor is meant for the Historical service, configure it in `historical/runtime.properties` rather than `_common/common.runtime.properties`. + +::: + +Metric monitoring is an essential part of Druid operations. The following table lists the monitors that are available and which service you should configure the monitor for: + +|Name|Description| +|----|-----------| +|`org.apache.druid.client.cache.CacheMonitor`|Emits metrics (to logs) about the segment results cache for Historical and Broker services. Reports typical cache statistics include hits, misses, rates, and size (bytes and number of entries), as well as timeouts and and errors.| +|`org.apache.druid.java.util.metrics.SysMonitor`|Reports on various system activities and statuses using the [SIGAR library](https://github.com/hyperic/sigar). Requires execute privileges on files in `java.io.tmpdir`. Do not set `java.io.tmpdir` to `noexec` when using `SysMonitor`.| Review Comment: ```suggestion |`org.apache.druid.java.util.metrics.OshiSysMonitor`|Reports on various system activities and statuses using the [OSHI](https://github.com/oshi/oshi), a JNA-based (native) Operating System and Hardware Information library for Java. Requires execute privileges on files in `java.io.tmpdir`. Do not set `java.io.tmpdir` to `noexec` when using `SysMonitor`.| ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
