Patroni 修改配置
背景
- 使用 Patroni 部署 postgresql 集群的时候，不能单独修改单点的配置，这里需要通过 Patroni 来修改配置。
修改步骤
1. 修改 postgres 集群的 max_connections 参数。
[root@postgres0 ~]# patronictl -c /etc/patroni.yml edit-config postgres
loop_wait: 10
maximum_lag_on_failover: 1048576
postgresql:
parameters:
# 注意：添加参数的时候，max_connections: 500 中间的冒号紧跟着一个**空格**，然后才是属性值。
max_connections: 500
use_pg_rewind: true
retry_timeout: 10
ttl: 30
---
+++
@@ -1,6 +1,8 @@
loop_wait: 10
maximum_lag_on_failover: 1048576
postgresql:
+ parameters:
+ max_connections: 500
use_pg_rewind: true
retry_timeout: 10
ttl: 30
# 这里输入 y ,应用所有更改。
Apply these changes? [y/N]:
1. 查看集群状态，最后一列状态栏 Pending restart 里面都是 * 号，表示配置已经修改，需要重启生效。
[root@loanapi ~]# patronictl -c /etc/patroni.yml list
+----------+--------+---------------+--------+---------+----+-----------+-----------------+
| Cluster | Member | Host | Role | State | TL | Lag in MB | Pending restart |
+----------+--------+---------------+--------+---------+----+-----------+-----------------+
| postgres | pg01 | 172.26.114.87 | | running | 4 | 0.0 | * |
| postgres | pg02 | 172.26.114.88 | | running | 4 | 0.0 | * |
| postgres | pg03 | 172.26.114.90 | Leader | running | 4 | 0.0 | * |
+----------+--------+---------------+--------+---------+----+-----------+-----------------+
1. 重启所有节点，使配置生效（重启一个再查看状态，就会发现 Pending restart 的星号没有了）。
[root@loanapi ~]# patronictl -c /etc/patroni.yml restart postgres pg01
When should the restart take place (e.g. 2019-09-11T10:49) [now]:
+----------+--------+---------------+--------+---------+----+-----------+-----------------+
| Cluster | Member | Host | Role | State | TL | Lag in MB | Pending restart |
+----------+--------+---------------+--------+---------+----+-----------+-----------------+
| postgres | pg01 | 172.26.114.87 | | running | 4 | 0.0 | * |
| postgres | pg02 | 172.26.114.88 | | running | 4 | 0.0 | * |
| postgres | pg03 | 172.26.114.90 | Leader | running | 4 | 0.0 | * |
+----------+--------+---------------+--------+---------+----+-----------+-----------------+
Are you sure you want to restart members pg01? [y/N]: y
Restart if the PostgreSQL version is less than provided (e.g. 9.5.2) []:
Success: restart on member pg01
补充信息
通过日志查看修改的内容是否正常。
# 如果你修改错了，页面上没有提示。
Sep 9 16:20:02 postgres0 patroni: 2019-09-09 16:20:02,337 INFO: Lock owner: pg01; I am pg01
Sep 9 16:20:02 postgres0 patroni: 2019-09-09 16:20:02,353 INFO: no action. i am the leader with the lock
Sep 9 16:20:02 postgres0 patroni: 2019-09-09 16:20:02,356 INFO: No PostgreSQL configuration items changed, nothing to reload.
# 如果你修改的对了，就会提示如下信息。
Sep 9 16:44:40 postgres0 patroni: 2019-09-09 16:44:40,046 INFO: no action. i am the leader with the lock
Sep 9 16:44:40 postgres0 patroni: 2019-09-09 16:44:40,081 INFO: Changed max_connections from 100 to 101 (restart required)
Sep 9 16:44:50 postgres0 patroni: 2019-09-09 16:44:50,027 INFO: Lock owner: pg01; I am pg01
Sep 9 16:44:50 postgres0 patroni: 2019-09-09 16:44:50,039 INFO: no action. i am the leader with the lock