Peons run a single task in a single JVM. MiddleManager is responsible for creating Peons for running tasks. Peons should rarely (if ever for testing purposes) be run on their own.
Although peons inherit the configurations of their parent middle managers, explicit child peon configs in middlemanager can be set by prefixing them with:
druid.indexer.fork.property
Additional peon configs include:
| Property | Description | Default |
|---|---|---|
druid.peon.mode | Choices are “local” and “remote”. Setting this to local means you intend to run the peon as a standalone node (Not recommended). | remote |
druid.indexer.task.baseDir | Base temporary working directory. | /tmp |
druid.indexer.task.baseTaskDir | Base temporary working directory for tasks. | /tmp/persistent/tasks |
druid.indexer.task.hadoopWorkingPath | Temporary working directory for Hadoop tasks. | /tmp/druid-indexing |
druid.indexer.task.defaultRowFlushBoundary | Highest row count before persisting to disk. Used for indexing generating tasks. | 50000 |
druid.indexer.task.chathandler.type | Choices are “noop” and “announce”. Certain tasks will use service discovery to announce an HTTP endpoint that events can be posted to. | noop |
If the peon is running in remote mode, there must be an overlord up and running. Running peons in remote mode require the following configurations:
| Property | Description | Default |
|---|---|---|
druid.peon.taskActionClient.retry.minWait | The minimum retry time to communicate with overlord. | PT1M |
druid.peon.taskActionClient.retry.maxWait | The maximum retry time to communicate with overlord. | PT10M |
druid.peon.taskActionClient.retry.maxRetryCount | The maximum number of retries to communicate with overlord. | 10 |
The peon should very rarely ever be run independent of the middle manager.
io.druid.cli.Main internal peon <task_file> <status_file>
The task file contains the task JSON object. The status file indicates where the task status will be output.