1. 在standby服务器安装postgres数据库,不需要初始化.
安装过程详见:http://www.cnblogs.com/ilifeilong/p/6979288.html
2. 在primary服务器创建具有REPLICATION权限的复制用户
- postgres=# CREATE ROLE repl WITH REPLICATION PASSWORD ‘repl‘ LOGIN;
3. 允许复制用户远程连接到primary服务器
- $ grep "^host" pg_hba.conf
- host all all 127.0.0.1/32 trust
- host replication repl 0.0.0.0/0 md5
- host all all ::1/128 trust
4. 在primary服务器设置流复制相关的参数
- $ mkdir /usr/local/pgsql/arch
- $ egrep "archive_mode|max_wal_senders|wal_keep_segments|archive_command|wal_level|hot_standby" postgresql.conf
- al_level = hot_standby # minimal, archive, hot_standby, or logical
- archive_mode = on # enables archiving; off, on, or always
- archive_command = ‘test ! -f /usr/local/pgsql/arch/%f && cp %p /usr/local/pgsql/arch/%f‘
- max_wal_senders = 5 # max number of walsender processes
- wal_keep_segments = 30 # in logfile segments, 16MB each; 0 disables
- hot_standby = on # "on" allows queries during recovery
- #hot_standby_feedback = off # send info from standby to prevent
5. 重新启动primary服务器进程
- $ pg_ctl stop -m fast
- $ pg_ctl start
6. 对primary服务器做一个全备并传输到standby服务器
- 在primary服务器通过pg_(start|stop)_backup函数进行备份
- postgres=# SELECT pg_start_backup(‘label‘, true);
- pg_start_backup
- -----------------
- 7/E6000060
- (1 row)
- $ rsync -az --progress ${PGDATA} postgres@10.189.100.195:/usr/local/pgsql/ --exclude postmaster.pid
- postgres=# SELECT pg_stop_backup();
- NOTICE: pg_stop_backup complete, all required WAL segments have been archived
- pg_stop_backup
- ----------------
- 7/E60005C8
- (1 row)
在standby服务器通过pg_basebackup命令进行备份,要求standby的PGDATA目录为空
- $ pg_basebackup --host=10.189.102.118 --username=repl --port=5432 --label=backup --verbose --progress --pgdata=/usr/local/pgsql/data --checkpoint=fast --format=p --xlog-method=stream
- Password:
- transaction log start point: 7/EA000028 on timeline 1
- pg_basebackup: starting background WAL receiver
- 65933562/65933562 kB (100%), 1/1 tablespace
- transaction log end point: 7/EA000830
- pg_basebackup: waiting for background process to finish streaming ...
- pg_basebackup: base backup completed
7. 设置standby数据库复制相关参数,使得standby失效转移后可以作为主库工作
- $ mkdir /usr/local/pgsql/arch
- $ egrep "archive_mode|max_wal_senders|wal_keep_segments|archive_command|wal_level|hot_standby" postgresql.conf
- wal_level = hot_standby # minimal, archive, hot_standby, or logical
- archive_mode = on # enables archiving; off, on, or always
- archive_command = ‘test ! -f /usr/local/pgsql/arch/%f && cp %p /usr/local/pgsql/arch/%f‘
- max_wal_senders = 5 # max number of walsender processes
- wal_keep_segments = 30 # in logfile segments, 16MB each; 0 disables
- hot_standby = on # "on" allows queries during recovery
- #hot_standby_feedback = off # send info from standby to prevent
8. 在standby文件创建恢复文件
- $ cat recovery.conf
- restore_command = ‘cp /usr/local/pgsql/arch/%f "%p"‘
- standby_mode = ‘on‘
- primary_conninfo = ‘user=repl password=repl host=10.189.102.118 port=5432 sslmode=disable sslcompression=1‘
- archive_cleanup_command = ‘pg_archivecleanup -d /usr/local/pgsql/arch %r >> /usr/local/pgsql/arch/archive_cleanup.log‘
- trigger_file = ‘/usr/local/pgsql/data/trigger_active_standby‘
9. 启动standby数据库进程,自动启动流复制
- $ pg_ctl start -w
- waiting for server to start....LOG: could not create IPv6 socket: Address family not supported by protocol
- LOG: redirecting log output to logging collector process
- HINT: Future log output will appear in directory "pg_log".
- done
- server started
10. 检查primary和standby数据库的延迟
- 通过函数和系统表查看
- edbstore=# select * from pg_stat_replication; #在primary主库查看
- -[ RECORD 1 ]----+------------------------------
- pid | 15013
- usesysid | 19206
- usename | repl
- application_name | walreceiver
- client_addr | 10.189.100.195
- client_hostname |
- client_port | 56072
- backend_start | 2017-06-13 08:10:35.400508-07
- backend_xmin |
- state | streaming
- sent_location | 7/EC01A588
- write_location | 7/EC01A588
- flush_location | 7/EC01A588
- replay_location | 7/EC01A588
- sync_priority | 0
- sync_state | async
- edbstore=# SELECT pg_current_xlog_location(); #在primary主库查看
- pg_current_xlog_location
- --------------------------
- 7/EC01A588
- (1 row)
- postgres=# select pg_last_xlog_receive_location(),pg_last_xlog_replay_location(),pg_last_xact_replay_timestamp(); #在standby备库查看
- pg_last_xlog_receive_location | pg_last_xlog_replay_location | pg_last_xact_replay_timestamp
- -------------------------------+------------------------------+-------------------------------
- 7/EC01A588 | 7/EC01A588 | 2017-06-13 08:25:20.281568-07
- (1 row)
- 通过进程查看
- $ ps -ef | grep sender | grep -v grep #在primary库查看
- postgres 15013 24883 0 08:10 ? 00:00:00 postgres: wal sender process repl 10.189.100.195(56072) streaming 7/EC01A668
- $ ps -ef | grep receiver | grep -v grep #在standby库查看
- postgres 12857 12843 0 08:10 ? 00:00:00 postgres: wal receiver process streaming 7/EC01A668
