druid/docs/design/middlemanager.md

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---
id: middlemanager
title: "MiddleManager service"
sidebar_label: "MiddleManager"
---
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The MiddleManager service is a worker service that executes submitted tasks. MiddleManagers forward tasks to [Peons](../design/peons.md) 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.
## Configuration
For Apache Druid MiddleManager service configuration, see [MiddleManager and Peons](../configuration/index.md#middlemanager-and-peons).
For basic tuning guidance for the MiddleManager service, see [Basic cluster tuning](../operations/basic-cluster-tuning.md#middlemanager).
## HTTP endpoints
For a list of API endpoints supported by the MiddleManager, see the [Service status API reference](../api-reference/service-status-api.md#middlemanager).
## Running
```
org.apache.druid.cli.Main server middleManager
```