druid/docs/design/middlemanager.md

---
id: middlemanager
title: "Middle Manager service"
sidebar_label: "Middle Manager"
---

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The Middle Manager service is a worker service that executes submitted tasks. Middle Managers 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, whereas a Middle Manager may have multiple Peons.

## Configuration

For Apache Druid Middle Manager service configuration, see [Middle Manager and Peons](../configuration/index.md#middle-manager-and-peon).

For basic tuning guidance for the Middle Manager service, see [Basic cluster tuning](../operations/basic-cluster-tuning.md#middle-manager).

## HTTP endpoints

For a list of API endpoints supported by the Middle Manager, see the [Service status API reference](../api-reference/service-status-api.md#middle-manager).

## Running

```
org.apache.druid.cli.Main server middleManager
```