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主备切换

在快速入门文章中我们介绍了 OpenTenBase 的架构、源码编译安装、集群运行状态、启动停止等内容。

在应用接入中我们介绍了应用程序连接 OpenTenBase 数据库进行建库、建表、数据导入、查询等操作。

在基本使用中我们介绍 OpenTenBase 中特有的shard表、复制表的创建，和基本的DML操作。

在高级使用中我们介绍 OpenTenBase 的高级使用操作内容，其中包含了各种窗口函数、Json/Jsonb、游标、事务、锁等的使用。

在组件安装及管理中我们深入到 OpenTenBase 各种组件内部，对各种组件的初始化、参数配置、启停、运行状态查看、路由生效配置等进行单独的详细介绍。

在本篇文章中我们将对 OpenTenBase 内部各种组件的主备角色如何切换进行详细介绍。

环境部署

  • 服务器数量

2台，IP分别为： 172.16.0.29，172.16.0.47

  • 硬件配置

CPU：4核
内存：8G
系统盘：50G
数据盘：200G

  • 操作系统要求

centos7.3

创建OS用户

  • 创建操作系统运行用户 
[root@VM_0_29_centos ~]# adduser -d /data/opentenbase opentenbase
  • 配置操作系统用户密码 
[root@VM_0_29_centos pgxztmp]# passwd opentenbase
  • 创建opentenbase应用程序运行目录 
[root@VM_0_29_centos pgxz]# su opentenbase  
[opentenbase@VM_0_29_centos install]$ mkdir -p /data/opentenbase/install/pgxz
  • 创建opentenbase数据目录 
[root@VM_0_29_centos pgxz]# su opentenbase  
[opentenbase@VM_0_29_centos install]$ mkdir -p /data/opentenbase/data/pgxz
  • 上传pgxz应用程序到目录/data/opentenbase/install/pgxz下面，目录的结构为 
[opentenbase@VM_0_29_centos pgxz]$ ll /data/opentenbase/install/pgxz
total 4
drwxrwxr-x 2 pgxz pgxz 4096 Nov 10 04:33 bin
drwxrwxr-x 4 pgxz pgxz  189 Nov 10 04:33 include
drwxrwxr-x 4 pgxz pgxz  172 Nov 10 04:33 lib
drwxrwxr-x 3 pgxz pgxz   24 Oct  1 14:54 share
[opentenbase@VM_0_29_centos pgxz]$
  • 配置pgxz用户的环境变量
[opentenbase@VM_0_29_centos ~]$ vim /data/opentenbase/.bashrc 
# .bashrc

# Source global definitions
if [ -f /etc/bashrc ]; then
        . /etc/bashrc
fi

export OPENTENBASE_HOME=/data/opentenbase/install/pgxz
export PATH=$OPENTENBASE_HOME/bin:$PATH
export LD_LIBRARY_PATH=$OPENTENBASE_HOME/lib:${LD_LIBRARY_PATH}

配置公共参数

[opentenbase@VM_0_29_centos ~]# mkdir -p /data/opentenbase/global/
[opentenbase@VM_0_29_centos ~]#vim /data/opentenbase/global/postgresql.conf.user

listen_addresses = '0.0.0.0'
max_connections = 500
max_pool_size = 65535
shared_buffers = 1GB                    
max_prepared_transactions = 2000
maintenance_work_mem = 256MB
wal_level = logical
max_wal_senders = 64
max_wal_size = 1GB
min_wal_size = 256MB
log_destination = 'csvlog'
logging_collector = on
log_directory = 'log'
log_filename = 'postgresql-%A-%H.log' 
synchronous_commit = local
synchronous_standby_names = ''

安装配置拓补结构说明

节点名称 IP 目录
gtm主 172.16.0.29 /data/opentenbase/data/pgxz/gtm
gtm备 172.16.0.47 /data/opentenbase/data/pgxz/gtm
cn01 172.16.0.29 /data/opentenbase/data/pgxz/cn01
cn02 172.16.0.47 /data/opentenbase/data/pgxz/cn02
dn01主 172.16.0.29 /data/opentenbase/data/pgxz/dn01
dn01备 172.16.0.47 /data/opentenbase/data/pgxz/dn01
dn02主 172.16.0.47 /data/opentenbase/data/pgxz/dn02
dn02备 172.16.0.29 /data/opentenbase/data/pgxz/dn02

DN主备切换

模似DN01主故障

[opentenbase@VM_0_29_centos ~]# pg_ctl -Z datanode -D /data/opentenbase/data/pgxz/dn01 stop -m f

将DN01备提升为主

[opentenbase@VM_0_47_centos ~]# pg_ctl -Z datanode -D /data/opentenbase/data/pgxz/dn01 promote

CN01主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.29 -p 15432 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter node dn01 with (host='172.16.0.47',port=23001);

CN02主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.47 -p 15432 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter node dn01 with (host='172.16.0.47',port=23001);

DN01主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.47 -p 23001 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter node dn01 with (host='172.16.0.47',port=23001);

注意这里要连接到新主

DN02主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.47 -p 23002 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter node dn01 with (host='172.16.0.47',port=23001);

说明：CN的主备切换和DN类似，只是在模拟CN故障和提升备节点时将-Z参数改为coordinator，因此不在赘述
pg_ctl -Z coordinator -D ${CN节点数据目录} [stop -m f | promote]

GTM主备切换

模似GTM主故障

[opentenbase@VM_0_29_centos ~]# gtm_ctl -Z gtm -D /data/opentenbase/data/pgxz/gtm stop

将GTM备提升为主

[opentenbase@VM_0_47_centos ~]# gtm_ctl -Z gtm -D /data/opentenbase/data/pgxz/gtm promote

CN01主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.29 -p 15432 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter gtm node gtm_1 with (host='172.16.0.47',port=21000);

CN02主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.47 -p 15432 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter gtm node gtm_1 with (host='172.16.0.47',port=21000);

DN01主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.47 -p 23001 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter gtm node gtm_1 with (host='172.16.0.47',port=21000);

注意这里要连接到新主

DN02主路由变更

[opentenbase@VM_0_29_centos ~]# psql -h 172.16.0.47 -p 23002 -d postgres -U opentenbase
psql (PostgreSQL 10.0 opentenbase V2)
Type "help" for help.

postgres=# alter gtm node gtm_1 with (host='172.16.0.47',port=21000);