The MiddleManager service is a worker service that executes submitted tasks. MiddleManagers forward tasks to Peons that run in separate JVMs. Druid uses separate JVMs for tasks to isolate resources and logs. Each Peon is capable of running only one task at a time, wheres a MiddleManager may have multiple Peons.
For Apache Druid MiddleManager service configuration, see MiddleManager and Peons.
For basic tuning guidance for the MiddleManager service, see Basic cluster tuning.
For a list of API endpoints supported by the MiddleManager, see the Service status API reference.
org.apache.druid.cli.Main server middleManager