2011/8/5 Jun Ishiduka <ishizuka....@po.ntts.co.jp>: > * Procedure > > 1. Call pg_start_backup('x') on the standby. > 2. Take a backup of the data dir. > 3. Call pg_stop_backup() on the standby. > 4. Copy the control file on the standby to the backup. > 5. Check whether the control file is status during hot standby with > pg_controldata. > -> If the standby promote between 3. and 4., the backup can not recovery. > -> pg_control is that "Minimum recovery ending location" is equals 0/0. > -> backup-end record is not written.
What if we do #4 before #3? The backup gets corrupted? My guess is that the backup is still valid even if we copy pg_control before executing pg_stop_backup(). Which would not require #5 because if the standby promotion happens before pg_stop_backup(), pg_stop_backup() can detect that status change and cancel the backup. #5 looks fragile. If we can get rid of it, the procedure becomes more robust, I think. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers