OpenTenBase · enkilee · Feb 1, 2024
diff --git a/docs/guide/06-switching.en.md b/docs/guide/06-switching.en.md
@@ -0,0 +1,233 @@
+# Failover
+
+>In [Quick Start](01-quickstart.en.md) article, we introduced opentenbase architecture, source code compilation and installation, cluster running status, startup and stop, etc.
+>
+>In [Access](02-access.md) article, we introduced the application program to connect opentenbase for database creation, table creation, data import, query and other operations.
+>
+>In [Basic Use](03-basic-use.md) article, we introduced the creation of shard table, cold and hot partition table, replication table in opentenbase, and basic DML operations.
+>
+>In [Advanced Use](04-advanced-use.md) article, we introduced the advanced use of opentenbase, including the use of various window functions, Json/Jsonb, cursors, transactions, locks, etc.
+>
+>In [组件安装及管理](05-component.md) article, we dive into the internal of various components of opentenbase, and introduced the initialization, parameter configuration, startup and stop, running status viewing, routing effective configuration of various components separately.
+>
+>In this article, we will introduce in detail how to switch the master and standby roles of various components in opentenbase.
+
+## Environment Deployment
+- Number of servers
+
+  Two servers, IP's are： 172.16.0.29，172.16.0.47
+
+- Hardware configuration
+
+  CPU：4 core+
+  Memory：8 GB+
+  System Disk：50GB+  
+  Data Disk：200G+  
+
+- Operation system requirements
+
+  CentOS 7.3  
+
+## Create OS user
+-	Create operating system running user
+
+```
+[root@VM_0_29_centos ~]# adduser -d /data/opentenbase opentenbase
+```
+
+- Configure the operating system user password
+
+```
+[root@VM_0_29_centos pgxztmp]# passwd opentenbase
+```
+
+- Create opentenbase application program running directory
+
+```
+[root@VM_0_29_centos pgxz]# su opentenbase  
+[opentenbase@VM_0_29_centos install]$ mkdir -p /data/opentenbase/install/pgxz
+```
+
+- Create opentenbase data directory
+
+```
+[root@VM_0_29_centos pgxz]# su opentenbase  
+[opentenbase@VM_0_29_centos install]$ mkdir -p /data/opentenbase/data/pgxz
+```
+
+-	Upload `pgxz` application program to directory `/data/opentenbase/install/pgxz`, the directory structure is
+
+```
+[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]$ 
+```
+
+- Configure the environment variables for user 'pgxz'
+
+```
+[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}
+```
+
+## Configure public parameters
+
+```
+[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 = '' 
+```
+
+## Install and configure GTM
+
+ | Node     IP    |  Directory
+-------|:-----------:|-------------------------
+gtm master  | 172.16.0.29 | /data/opentenbase/data/pgxz/gtm
+gtm standby | 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 master	| 172.16.0.29 | /data/opentenbase/data/pgxz/dn01
+dn01 standby	| 172.16.0.47 | /data/opentenbase/data/pgxz/dn01
+dn02 master	| 172.16.0.47 | /data/opentenbase/data/pgxz/dn02
+dn02 stangdy	| 172.16.0.29 | /data/opentenbase/data/pgxz/dn02
+
+
+# DN Failover
+## Simulate DN01 master failure
+
+```
+[opentenbase@VM_0_29_centos ~]# pg_ctl -Z datanode -D /data/opentenbase/data/pgxz/dn01 stop -m f  
+```
+
+## Switch DN01 standby to master
+
+```
+[opentenbase@VM_0_47_centos ~]# pg_ctl -Z datanode -D /data/opentenbase/data/pgxz/dn01 promote 
+```
+
+## Switch main route of CN01
+
+```
+[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);
+```
+
+## Switch main route of CN02
+
+```
+[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);
+```
+
+## Switch main route of DN01
+
+```
+[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);
+```
+
+**Notice that here we need connect to new route**
+
+## Switch main route of DN02
+
+```
+[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 Failover
+## Simulate GTM master failure
+
+```
+[opentenbase@VM_0_29_centos ~]# gtm_ctl -Z gtm -D /data/opentenbase/data/pgxz/gtm stop 
+```
+
+## Promote GTM standby to master
+
+```
+[opentenbase@VM_0_47_centos ~]# gtm_ctl -Z gtm -D /data/opentenbase/data/pgxz/gtm promote 
+```
+
+## Switch main route of CN01
+
+```
+[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);
+```
+
+## Switch main route of CN02
+
+```
+[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);
+```
+
+## Switch main route of DN01
+
+```
+[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);
+```
+
+**Notice that here we need connect to new route**
+## Switch main route of DN02
+
+```
+[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);
+```