patroni安装使用

patroni

patroni 依赖第三方分布式存储, 可以托管 postgres 的配置管理和启停, 以及主备切换.

安装

安装epel源，安装pyhton3

yum -y install epel-release
yum -y install python3 python3-devel

pip安装patroni

官方文档

yum install -y python3-psycopg2
pip3 install patroni[etcd3,psycopg2]
# 执行patroni命令无报错证明安装完成
[root@data8 data]# patroni
Config is empty.

pip3 卸载命令: pip3 uninstall xxxx

生成patroni配置文件

patroni --generate-sample-config /etc/patroni/patroni.yml

官方配置文件详细说明

patroni 配置文件样例

scope: 'pg' # 集群名称,保持一致
namespace: '/service' # 保持默认
name: data7 # 不同节点设置不同的name

log:
  format: '%(asctime)s %(levelname)s: %(message)s'
  level: INFO
  max_queue_size: 1000
  traceback_level: ERROR
  type: plain

restapi:
  connect_address: 172.16.20.152:8008
  listen: 172.16.20.152:8008

# 这里使用的是etcd3
etcd3:
  hosts: 172.16.20.152:2379,172.16.20.153:2379,172.16.20.154:2379

# The bootstrap configuration. Works only when the cluster is not yet initialized.
# If the cluster is already initialized, all changes in the `bootstrap` section are ignored!
bootstrap:
  # This section will be written into <dcs>:/<namespace>/<scope>/config after initializing
  # new cluster and all other cluster members will use it as a `global configuration`.
  # WARNING! If you want to change any of the parameters that were set up
  # via `bootstrap.dcs` section, please use `patronictl edit-config`!
  dcs:
    loop_wait: 10
    retry_timeout: 10
    ttl: 30
    postgresql:
      parameters:
        hot_standby: 'on'
        max_connections: 200
        max_locks_per_transaction: 64
        max_prepared_transactions: 0
        max_replication_slots: 10
        max_wal_senders: 10
        max_worker_processes: 8
        track_commit_timestamp: 'off'
        wal_keep_size: 128MB
        wal_level: replica
        wal_log_hints: 'on'
      use_pg_rewind: true
      use_slots: true
  initdb:
  - data-checksums
  - encoding: UTF8

postgresql:
  # 这里的用户patroni会自动生成,直接写好用户密码即可.
  authentication:
    replication:
      password: 'replicator'
      username: replicator
    rewind:
      password: 'rewind_user'
      username: rewind_user
    superuser:
      password: '123456'
      username: postgres
  connect_address: 172.16.20.152:5432
  data_dir: '/home/pgsql/data/' # 指定data目录,需要设置好权限,可以是空目录表示一个新的pg集群,会自动初始化
  bin_dir: '/usr/local/pgsql/bin/' # 指定pg的安装的bin目录
  listen: 0.0.0.0:5432 # 监听0.0.0.0
  parameters:
    # centos7 直接启动时会报错：SCRAM authentication requires libpq version 10 or above。解决办法写在后面。
    password_encryption: scram-sha-256
  pg_hba:
  - host all all 0.0.0.0/0 md5
  - host replication replicator 172.16.20.0/24 md5
  #callbacks:
  #  on_reload: /etc/patroni/on_reload.sh
  #  on_restart: /etc/patroni/on_restart.sh
  #  on_role_change: /etc/patroni/on_role_change.sh
  #  on_start: /etc/patroni/on_start.sh
  #  on_stop: /etc/patroni/on_stop.sh

tags:
  clonefrom: true
  failover_priority: 1
  noloadbalance: false
  nostream: false
  nosync: false

脚本示例:

#!/bin/bash
curl -X GET http://172.16.20.35:8085/ping/152/on_start

注意#!/bin/bash解析器一定要写，不然patroni执行报错.

[Unit]
Description=Runners to orchestrate a high-availability PostgreSQL
After=syslog.target network.target
 
[Service]
Type=simple
User=postgres
Group=postgres
ExecStart=/usr/local/bin/patroni /etc/patroni/patroni.yml
ExecReload=/bin/kill -s HUP $MAINPID
KillMode=process
TimeoutSec=30
Restart=no
 
[Install]
WantedBy=multi-user.target

启动patroni

# 启动
systemctl start patroni
# 检查运行状态,并查看pg data目录是否有数据了.
systemctl status patroni

查询patroni节点状态

[root@data7 data]# patronictl -c /etc/patroni/patroni.yml list
+ Cluster: pg (7384360501716690603) -----------+----+-----------+----------------------+
| Member | Host          | Role    | State     | TL | Lag in MB | Tags                 |
+--------+---------------+---------+-----------+----+-----------+----------------------+
| data7  | 172.16.20.152 | Leader  | running   |  1 |           | clonefrom: true      |
|        |               |         |           |    |           | failover_priority: 1 |
+--------+---------------+---------+-----------+----+-----------+----------------------+
| data8  | 172.16.20.153 | Replica | streaming |  1 |         0 | clonefrom: true      |
|        |               |         |           |    |           | failover_priority: 1 |
+--------+---------------+---------+-----------+----+-----------+----------------------+
| data9  | 172.16.20.154 | Replica | streaming |  1 |         0 | clonefrom: true      |
|        |               |         |           |    |           | failover_priority: 1 |
+--------+---------------+---------+-----------+----+-----------+----------------------+

错误

SCRAM authentication requires libpq version 10 or above
这个错误原因是 centos7 默认安装的 postgresql-libs 版本太低,需要升级.

[root@data8 data]# yum list installed | grep postgre
postgresql-libs.x86_64                 9.2.24-9.el7_9                  @updates

卸载现有的lib

yum remove -y postgresql-libs.x86_64

安装pg yum 源

yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

安装最新的,注意: centos最高只支持 15 版本

yum install postgresql15-libs -y

确认

[root@data8 data]# yum list installed | grep postgre
postgresql15-libs.x86_64               15.7-1PGDG.rhel7                @pgdg15

注意,重新安装lib后patroni运行会报错

 FATAL: Patroni requires psycopg2>=2.5.4, psycopg2-binary, or psycopg>=3.0.0

需要重新安装

yum install -y python3-psycopg2