Enabling Metrics
Druid nodes periodically emit metrics and different metrics monitors can be included. Each node can overwrite the default list of monitors.
| Property | Description | Default |
|---|---|---|
druid.monitoring.emissionPeriod |
How often metrics are emitted. | PT1m |
druid.monitoring.monitors |
Sets list of Druid monitors used by a node. See below for names and more information. For example, you can specify monitors for a Broker withdruid.monitoring.monitors=["io.druid.java.util.metrics.SysMonitor","io.druid.java.util.metrics.JvmMonitor"]. |
none (no monitors) |
The following monitors are available:
| Name | Description |
|---|---|
io.druid.client.cache.CacheMonitor |
Emits metrics (to logs) about the segment results cache for Historical and Broker nodes. Reports typical cache statistics include hits, misses, rates, and size (bytes and number of entries), as well as timeouts and and errors. |
io.druid.java.util.metrics.SysMonitor |
This uses the SIGAR library to report on various system activities and statuses. |
io.druid.server.metrics.HistoricalMetricsMonitor |
Reports statistics on Historical nodes. |
io.druid.java.util.metrics.JvmMonitor |
Reports various JVM-related statistics. |
io.druid.java.util.metrics.JvmCpuMonitor |
Reports statistics of CPU consumption by the JVM. |
io.druid.java.util.metrics.CpuAcctDeltaMonitor |
Reports consumed CPU as per the cpuacct cgroup. |
io.druid.java.util.metrics.JvmThreadsMonitor |
Reports Thread statistics in the JVM, like numbers of total, daemon, started, died threads. |
io.druid.segment.realtime.RealtimeMetricsMonitor |
Reports statistics on Realtime nodes. |
io.druid.server.metrics.EventReceiverFirehoseMonitor |
Reports how many events have been queued in the EventReceiverFirehose. |
io.druid.server.metrics.QueryCountStatsMonitor |
Reports how many queries have been successful/failed/interrupted. |
io.druid.server.emitter.HttpEmitterMonitor |
Reports internal metrics of http or parametrized emitter (see below). Must not be used with another emitter type. See the description of the metrics here: https://github.com/druid-io/druid/pull/4973. |
Emitting Metrics
The Druid servers emit various metrics and alerts via something we call an Emitter. There are three emitter implementations included with the code, a "noop" emitter, one that just logs to log4j ("logging", which is used by default if no emitter is specified) and one that does POSTs of JSON events to a server ("http"). The properties for using the logging emitter are described below.
| Property | Description | Default |
|---|---|---|
druid.emitter |
Setting this value to "noop", "logging", "http" or "parametrized" will initialize one of the emitter modules. value "composing" can be used to initialize multiple emitter modules. | noop |
Logging Emitter Module
| Property | Description | Default |
|---|---|---|
druid.emitter.logging.loggerClass |
Choices: HttpPostEmitter, LoggingEmitter, NoopServiceEmitter, ServiceEmitter. The class used for logging. | LoggingEmitter |
druid.emitter.logging.logLevel |
Choices: debug, info, warn, error. The log level at which message are logged. | info |
Http Emitter Module
| Property | Description | Default |
|---|---|---|
druid.emitter.http.flushMillis |
How often the internal message buffer is flushed (data is sent). | 60000 |
druid.emitter.http.flushCount |
How many messages the internal message buffer can hold before flushing (sending). | 500 |
druid.emitter.http.basicAuthentication |
Login and password for authentification in "login:password" form, e. g.druid.emitter.http.basicAuthentication=admin:adminpassword |
not specified = no authentification |
| `druid.emitter.http.flushTimeOut | The timeout after which an event should be sent to the endpoint, even if internal buffers are not filled, in milliseconds. | not specified = no timeout |
druid.emitter.http.batchingStrategy |
The strategy of how the batch is formatted. "ARRAY" means[event1,event2], "NEWLINES" means event1\nevent2, ONLY_EVENTS means event1event2. |
ARRAY |
druid.emitter.http.maxBatchSize |
The maximum batch size, in bytes. | the minimum of (10% of JVM heap size divided by 2) or (5191680 (i. e. 5 MB)) |
druid.emitter.http.batchQueueSizeLimit |
The maximum number of batches in emitter queue, if there are problems with emitting. | the maximum of (2) or (10% of the JVM heap size divided by 5MB) |
druid.emitter.http.minHttpTimeoutMillis |
If the speed of filling batches imposes timeout smaller than that, not even trying to send batch to endpoint, because it will likely fail, not being able to send the data that fast. Configure this depending based on emitter/successfulSending/minTimeMs metric. Reasonable values are 10ms..100ms. | 0 |
druid.emitter.http.recipientBaseUrl |
The base URL to emit messages to. Druid will POST JSON to be consumed at the HTTP endpoint specified by this property. | none, required config |
Parametrized Http Emitter Module
druid.emitter.parametrized.httpEmitting.* configs correspond to the configs of Http Emitter Modules, see above. ExceptrecipientBaseUrl. E. g. druid.emitter.parametrized.httpEmitting.flushMillis,druid.emitter.parametrized.httpEmitting.flushCount, etc.
The additional configs are:
| Property | Description | Default |
|---|---|---|
druid.emitter.parametrized.recipientBaseUrlPattern |
The URL pattern to send an event to, based on the event's feed. E. g. http://foo.bar/{feed}, that will send event tohttp://foo.bar/metrics if the event's feed is "metrics". |
none, required config |
Composing Emitter Module
| Property | Description | Default |
|---|---|---|
druid.emitter.composing.emitters |
List of emitter modules to load e.g. ["logging","http"]. | [] |
Graphite Emitter
To use graphite as emitter set druid.emitter=graphite. For configuration details please follow this link.
Metadata Storage
These properties specify the jdbc connection and other configuration around the metadata storage. The only processes that connect to the metadata storage with these properties are the Coordinator, Indexing service and Realtime Nodes.
| Property | Description | Default |
|---|---|---|
druid.metadata.storage.type |
The type of metadata storage to use. Choose from "mysql", "postgresql", or "derby". | derby |
druid.metadata.storage.connector.connectURI |
The jdbc uri for the database to connect to | none |
druid.metadata.storage.connector.user |
The username to connect with. | none |
druid.metadata.storage.connector.password |
The Password Provider or String password used to connect with. | none |
druid.metadata.storage.connector.createTables |
If Druid requires a table and it doesn't exist, create it? | true |
druid.metadata.storage.tables.base |
The base name for tables. | druid |
druid.metadata.storage.tables.segments |
The table to use to look for segments. | druid_segments |
druid.metadata.storage.tables.rules |
The table to use to look for segment load/drop rules. | druid_rules |
druid.metadata.storage.tables.config |
The table to use to look for configs. | druid_config |
druid.metadata.storage.tables.tasks |
Used by the indexing service to store tasks. | druid_tasks |
druid.metadata.storage.tables.taskLog |
Used by the indexing service to store task logs. | druid_taskLog |
druid.metadata.storage.tables.taskLock |
Used by the indexing service to store task locks. | druid_taskLock |
druid.metadata.storage.tables.supervisors |
Used by the indexing service to store supervisor configurations. | druid_supervisors |
druid.metadata.storage.tables.audit |
The table to use for audit history of configuration changes e.g. Coordinator rules. | druid_audit |