Recovery procedure of Postgresql

Any operation is from the view of standby server.

1

Execute restore_command to restore xlog to pg_xlog folder from archive folder.
If either streaming replication disabled, disconnected or recovery failed, go to 4.

2

If xlog found,try to restore any available WAL in pg_xlog folder since current last valid record until last available data consistent point int WAL.
Otherwise go to 3.

3

If streaming enabled, Standby will try to connect to primary and start streaming WAL and recovery since last valid record found in pg_xlog folder.
Otherwise go to 1

4

If the above procedure repeated for several times or trigger file is created, recovery cancelled.