<commit_before><!--[metadata]>
+++
aliases = [
"/engine/swarm/manager-administration-guide/"
]
title = "Swarm administration guide"
description = "Manager administration guide"
keywords = ["docker, container, swarm, manager, raft"]
[menu.main]
identifier="manager_admin_guide"
parent="engine_swarm"
weight="20"
+++
<![end-metadata]-->

# Administer and maintain a swarm of Docker Engines

When you run a swarm of Docker Engines, **manager nodes** are the key components
for managing the swarm and storing the swarm state. It is important to
understand some key features of manager nodes in order to properly deploy and
maintain the swarm.

This article covers the following swarm administration tasks:

* [Using a static IP for manager node advertise address](#use-a-static-ip-for-manager-node-advertise-address)
* [Adding manager nodes for fault tolerance](#add-manager-nodes-for-fault-tolerance)
* [Distributing manager nodes](#distribute-manager-nodes)
* [Running manager-only nodes](#run-manager-only-nodes)
* [Backing up the swarm state](#back-up-the-swarm-state)
* [Monitoring the swarm health](#monitor-swarm-health)
* [Troubleshooting a manager node](#troubleshoot-a-manager-node)
* [Forcefully removing a node](#force-remove-a-node)
* [Recovering from disaster](#recover-from-disaster)

Refer to [How swarm mode nodes work](how-swarm-mode-works/nodes.md)
for a brief overview of Docker Swarm mode and the difference between manager and
worker nodes.

## Operating manager nodes in a swarm

Swarm manager nodes use the [Raft Consensus Algorithm](raft.md) to manage the
swarm state. You only need to understand some general concepts of Raft in
order to manage a swarm.

There is no limit on the number of manager nodes. The decision about how many
manager nodes to implement is a trade-off between performance and
fault-tolerance. Adding manager nodes to a swarm makes the swarm more
fault-tolerant. However, additional manager nodes reduce write performance
because more nodes must acknowledge proposals to update the swarm state.
This means more network round-trip traffic.

Raft requires a majority of managers, also called a quorum, to agree on proposed
updates to the swarm. A quorum of managers must also agree on node additions
and removals. Membership operations are subject to the same constraints as state
replication.

## Use a static IP for manager node advertise address

When initiating a swarm, you have to specify the `--advertise-addr` flag to
advertise your address to other manager nodes in the swarm. For more<commit_msg>Remove the redundant description<commit_after><!--[metadata]>
+++
aliases = [
"/engine/swarm/manager-administration-guide/"
]
title = "Swarm administration guide"
description = "Manager administration guide"
keywords = ["docker, container, swarm, manager, raft"]
[menu.main]
identifier="manager_admin_guide"
parent="engine_swarm"
weight="20"
+++
<![end-metadata]-->

# Administer and maintain a swarm of Docker Engines

When you run a swarm of Docker Engines, **manager nodes** are the key components
for managing the swarm and storing the swarm state. It is important to
understand some key features of manager nodes in order to properly deploy and
maintain the swarm.

This article covers the following swarm administration tasks:

* [Using a static IP for manager node advertise address](#use-a-static-ip-for-manager-node-advertise-address)
* [Adding manager nodes for fault tolerance](#add-manager-nodes-for-fault-tolerance)
* [Distributing manager nodes](#distribute-manager-nodes)
* [Running manager-only nodes](#run-manager-only-nodes)
* [Backing up the swarm state](#back-up-the-swarm-state)
* [Monitoring the swarm health](#monitor-swarm-health)
* [Troubleshooting a manager node](#troubleshoot-a-manager-node)
* [Forcefully removing a node](#force-remove-a-node)
* [Recovering from disaster](#recover-from-disaster)

Refer to [How nodes work](how-swarm-mode-works/nodes.md)
for a brief overview of Docker Swarm mode and the difference between manager and
worker nodes.

## Operating manager nodes in a swarm

Swarm manager nodes use the [Raft Consensus Algorithm](raft.md) to manage the
swarm state. You only need to understand some general concepts of Raft in
order to manage a swarm.

There is no limit on the number of manager nodes. The decision about how many
manager nodes to implement is a trade-off between performance and
fault-tolerance. Adding manager nodes to a swarm makes the swarm more
fault-tolerant. However, additional manager nodes reduce write performance
because more nodes must acknowledge proposals to update the swarm state.
This means more network round-trip traffic.

Raft requires a majority of managers, also called a quorum, to agree on proposed
updates to the swarm. A quorum of managers must also agree on node additions
and removals. Membership operations are subject to the same constraints as state
replication.

## Use a static IP for manager node advertise address

When initiating a swarm, you have to specify the `--advertise-addr` flag to
advertise your address to other manager nodes in the swarm. For more
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