# Cluster management

> This document mainly introduces the management tools of TuGraph HA cluster, including the functions of deleting nodes, leader transfer and generating snapshots.

## 1 Introduction

After the HA cluster is started, you can use the `lgraph_peer` tool for cluster management, which can perform functions such as deleting nodes, transferring leaders, and generating snapshots.

## 2. Delete node

For nodes in the TuGraph HA cluster that are offline for a long time or have network partitions, you can use the `remove_peer` command of `lgraph_peer` to delete the node. An example command is as follows:
```shell
$ lgraph_peer --command remove_peer --peer {peer_id} --conf {group_conf}
```

in:

- `--command remove_peer` specifies that the operation to be performed is remove_peer, that is, delete the node.
- `--peer {peer_id}` specifies the rpc network address of the node to be deleted, such as `127.0.0.1:9092`.
- `--conf {group_conf}` specifies the member configuration of the HA cluster (as long as it can be connected to the master node), such as `127.0.0.1:9092,127.0.0.1:9093,127.0.0.1:9094`.

## 3. leader transfer

When you need to shut down or restart the master node, in order to reduce the unserviceable time of the cluster, you can use the `transfer_leader` command of `lgraph_peer` to transfer the master node. An example command is as follows:

```shell
$ lgraph_peer --command transfer_leader --peer {peer_id} --conf {group_conf}
```

in:

- `--command transfer_leader` specifies that the operation to be performed is transfer_leader, that is, transferring the master node.
- `--peer {peer_id}` specifies the rpc network address to become the master node, such as `127.0.0.1:9092`.
- `--conf {group_conf}` specifies the member configuration of the HA cluster (as long as it can be connected to the master node), such as `127.0.0.1:9092,127.0.0.1:9093,127.0.0.1:9094`.

## 4. Generate snapshot

For reasons such as setting ha_snapshot_interval_s to -1 when the node starts so that snapshots are not taken by default or other reasons,
when you need to tell a node generate a snapshot, you can use the `snapshot` command of `lgraph_peer`. An example command is as follows:

```shell
$ lgraph_peer --command snapshot --peer {peer_id}
```

in:

- `--command snapshot` specifies that the operation to be performed is snapshot, that is, generating a snapshot.
- `--peer {peer_id}` specifies the rpc network address of the node to generate a snapshot, such as `127.0.0.1:9092`.