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 NebulaGraph 3.2.1, switching leaders will cause a large number of short-term request errors (Storage Error E_RPC_FAILURE
). For solutions, see FAQ.
Last update:
February 1, 2023