On Wed, Aug 17, 2016 at 12:06 AM, Stephen Frost <sfr...@snowman.net> wrote:
> Greetings, > > * Venkata B Nagothi (nag1...@gmail.com) wrote: > > The above said parameters can be configured to pause, shutdown or prevent > > promotion only after reaching the recovery target point. > > To clarify, I am referring to a scenario where recovery target point is > not > > reached at all ( i mean, half-complete or in-complete recovery) and there > > are lots of WALs still pending to be replayed - in this situation, > > PG doesn't know that there are still WALs to be replayed. > PG doesn't know that there are still WALs to be replayed. Since, i have given an particular recovery target and PG knows the current replay position, I would say, it would be good if PG warns and pauses there by saying recovery target point is not reached. > It would be nice if PostgreSQL pauses the recovery in-case its not > complete > > (because of missing or corrupt WAL), shutdown the cluster and allows the > > DBA to restart the replay of the remaining WAL Archive files to continue > > recovery (from where it stopped previously) until the recovery target > point > > is reached. > Agreed. Reaching end-of-WAL is not an error. It sounds more like a limitation in certain scenarios. Reaching the end of WAL isn't an error and I don't believe it makes any > sense to treat it like it is. You can specify any recovery target point > you wish, including ones that don't exist, and that's not an error > either. > > I could see supporting an additional "pause" option that means "pause at > the end of WAL if you don't reach the recovery target point". I'd also > be happy with a warning being emitted in the log if the recovery target > point isn't reached before reaching the end of WAL, but I don't think it > makes sense to change the existing behavior. > Agreed. Additional option like "pause" would. As long as there is an option to ensure following happens if the recovery target is not reached - a) PG pauses the recovery at the end of the WAL b) Generates a warning in the log file saying that recovery target point is not reached (there is a patch being worked upon on by Thom on this) c) Does not open-up the database exiting from the recovery process by giving room to resume the replay of WALs Regards, Venkata B N Fujitsu Australia
