一、介绍
[postgres@test ~]$ pg_basebackup --help pg_basebackup takes a base backup of a running Postgresql server. Usage: pg_basebackup [OPTION]... Options controlling the output: -D,--pgdata=DIRECTORY receive base backup into directory -F,--format=p|t output format (plain (default),tar) -R,--write-recovery-conf write recovery.conf after backup -x,--xlog include required WAL files in backup (fetch mode) -X,--xlog-method=fetch|stream include required WAL files with specified method -z,--gzip compress tar output -Z,--compress=0-9 compress tar output with given compression level General options: -c,--checkpoint=fast|spread set fast or spread checkpointing -l,--label=LABEL set backup label -P,--progress show progress information -v,--verbose output verbose messages -V,--version output version information,then exit -?,--help show this help,then exit Connection options: -d,--dbname=CONNSTR connection string -h,--host=HOSTNAME database server host or socket directory -p,--port=PORT database server port number -s,--status-interval=INTERVAL time between status packets sent to server (in seconds) -U,--username=NAME connect as specified database user -w,--no-password never prompt for password -W,--password force password prompt (should happen automatically) Report bugs to .二、准备
主：10.1.11.71
从：10.1.11.72
VIP：10.1.11.73
PG 9.2.3
1.主备机安装(略)，以下修改都是在主机上修改除去第二点
备机只需要安装软件，不需要init数据库，主机开启归档和热备参数，在postgresql.conf文件里面配置
max_wal_senders = 2
wal_level = hot_standby
archive_mode = on
archive_command = 'cd ./'
hot_standby = on
wal_keep_segments = 32
2.配置信任关系(主机上都配置，减少切换后的操作)
a.配置
vi .pgpass
10.1.11.73:5678:postgres:repuser:123456
chmod 0400 .pgpass
b.配置pg_hba.conf
host all all 10.1.11.73/32 md5
c.创建流复制用户
postgres=# CREATE USER repuser replication LOGIN CONNECTION LIMIT 3 ENCRYPTED PASSWORD 'Rep_123';
d.检查备机的表空间和需要同步的数据文件路径，确保是空的，否则会报错
三、同步
在从机上执行
[postgres@test ~]$ pg_basebackup -D /database/pgdata/ -Fp -Xs -v -P -h 10.1.11.73 -U repuser -p 5678 transaction log start point: 2/DF000028 on timeline 3 pg_basebackup: starting background WAL receiver 177422/177422 kB (100%),1/1 tablespace transaction log end point: 2/DF015EE0 pg_basebackup: waiting for background process to finish streaming ... pg_basebackup: base backup completed四、同步后配置
1.修改reconvery.conf文件
如果主机上是recovery.done，那备机上传过来的这个文件需要改为recovery.conf，另外修改下内容,一般是改下IP密码居多
standby_mode = 'on' trigger_file = '/database/pgdata/postgresql.trigger.1949' primary_conninfo = 'host=10.1.11.73 port=5678 user=repuser password=123456 keepalives_idle=60'
五、启动验证
pg_ctl -$PGDATA start
六、参考
http://my.oschina.net/Kenyon/blog/54967
http://www.depesz.com/2011/01/24/waiting-for-9-1-pg_basebackup/
http://francs3.blog.163.com/blog/static/4057672720136210240967/
七、其他
这个工具印象上是linux的rsync功能外加支持DB在线部署，简化了之前的三步操作，另外支持在线数据同步，不需要另外关闭服务保证数据统一
