环境：
DB:Postgresql 9.1
VMWARE:6
前期准备略(包含热机和备机的安装及参数设置)。
问题1 参数配好启动备机时，日志显示
FATAL: Could not connect to the primary server: fe_sendauth: no password supplied
FATAL: Could not connect to the primary server: fe_sendauth: no password supplied FATAL: Could not connect to the primary server: fe_sendauth: no password supplied FATAL: Could not connect to the primary server: fe_sendauth: no password supplied FATAL: Could not connect to the primary server: fe_sendauth: no password supplied FATAL: Could not connect to the primary server: fe_sendauth: no password supplied FATAL: Could not connect to the primary server: fe_sendauth: no password supplied FATAL: Could not connect to the primary server: fe_sendauth: no password supplied该问题显示是密码没有提供，
但是检查.pgpass和primary_conninfo以及把primary_conninfo里面的内容拷贝出来psql一下
都是可以连接的，重新检查下参数，发现standby机子上的参数standby_mode这个参数没有调整，修改，使之standby_mode = on,再重启standby机子，结果这个问题就解决了，测试过程中发现，primary_conninfo中不设置password也会出现这个问题。
接来下却发生了下面这个问题。
问题2. standby日志显示：
FATAL: Could not connect to the primary server: FATAL: must be replication role to start walsender
FATAL: Could not connect to the primary server: FATAL: must be replication role to start walsender FATAL: Could not connect to the primary server: FATAL: must be replication role to start walsender FATAL: Could not connect to the primary server: FATAL: must be replication role to start walsender FATAL: Could not connect to the primary server: FATAL: must be replication role to start walsender在master端的日志显示：
FATAL: must be replication role to start walsender
FATAL: must be replication role to start walsender FATAL: must be replication role to start walsender FATAL: must be replication role to start walsender FATAL: must be replication role to start walsender FATAL: must be replication role to start walsender从日志上也可以看出，walsender的角色必须是replication，回到master端查看repuser，果然是没有配replication权限，只是普通用户。改之。
postgres=# CREATE USER repuser REPLICATION LOGIN CONNECTION LIMIT 3 ENCRYPTED PASSWORD 'repuser';
CREATE ROLE
postgres=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------+-----------
postgres | Superuser,Create role,Create DB,Replication | {}
repuser | Replication +| {}
| 3 connections 再次重启slave端的Postgresql，这次正常了。 查看master端的视图pg_stat_replication
postgres=# select procpid,usename,application_name,client_addr,client_port,state,sync_state from pg_stat_replication; procpid | usename | application_name | client_addr | client_port | state | sync_state ---------+---------+------------------+---------------+-------------+-----------+------------ 11816 | repuser | walreceiver | 192.168.2.134 | 41205 | streaming | async (1 row)
在本次创建user的过程发现，9.1版本的PG创建一个super用户时会默认带出replication权限。
postgres=# create user t_kenyon SUPERUSER ;
CREATE ROLE
postgres=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------+-----------
postgres | Superuser,Replication | {}
repuser | Replication +| {}
| 3 connections |
t_kenyon | Superuser,Replication | {}
总结：
repuser在9.1后已经不需要配置super权限，在配置流复制和其他复杂配置时需要小心仔细，避免一些不必要的麻烦。
