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Storage load balance

You can use the BALANCE statement to balance the distribution of partitions and Raft leaders, or clear some Storage servers for easy maintenance. For details, see BALANCE.

Danger

The BALANCE commands migrate data and balance the distribution of partitions by creating and executing a set of subtasks. DO NOT stop any machine in the cluster or change its IP address until all the subtasks finish. Otherwise, the follow-up subtasks fail.

Balance leader distribution

To balance the raft leaders, run BALANCE LEADER.

Example

nebula> BALANCE LEADER;

Run SHOW HOSTS to check the balance result.

nebula> SHOW HOSTS;
+------------------+------+-----------+----------+--------------+-----------------------------------+------------------------+---------+
| Host             | Port | HTTP port | Status   | Leader count | Leader distribution               | Partition distribution | Version |
+------------------+------+-----------+----------+--------------+-----------------------------------+------------------------+---------+
| "192.168.10.100" | 9779 | 19669     | "ONLINE" | 4            | "basketballplayer:3"              | "basketballplayer:8"   | "3.1.0" |
| "192.168.10.101" | 9779 | 19669     | "ONLINE" | 8            | "basketballplayer:3"              | "basketballplayer:8"   | "3.1.0" |
| "192.168.10.102" | 9779 | 19669     | "ONLINE" | 3            | "basketballplayer:3"              | "basketballplayer:8"   | "3.1.0" |
| "192.168.10.103" | 9779 | 19669     | "ONLINE" | 0            | "basketballplayer:2"              | "basketballplayer:7"   | "3.1.0" |
| "192.168.10.104" | 9779 | 19669     | "ONLINE" | 0            | "basketballplayer:2"              | "basketballplayer:7"   | "3.1.0" |
| "192.168.10.105" | 9779 | 19669     | "ONLINE" | 0            | "basketballplayer:2"              | "basketballplayer:7"   | "3.1.0" |
+------------------+------+-----------+----------+--------------+-----------------------------------+------------------------+---------+

Caution

In Nebula Graph 3.2.0, switching leaders will cause a large number of short-term request errors (Storage Error E_RPC_FAILURE). For solutions, see FAQ.


Last update: August 12, 2022