Hi Simon, Thanks for the comments!
On Thu, Apr 16, 2009 at 2:56 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > > On Wed, 2009-04-15 at 17:02 +0900, Fujii Masao wrote: > >> On Tue, Apr 14, 2009 at 2:41 PM, Fujii Masao <masao.fu...@gmail.com> wrote: >> > I'd like to propose another simple idea; pg_standby deletes the >> > trigger file *whenever* the nextWALfile is a timeline history file. >> > A timeline history file is restored at the end of recovery, so it's >> > guaranteed that the trigger file is deleted whether nextWALfile >> > exists or not. >> > >> > A timeline history file is restored also at the beginning of >> > recovery, so the accidentally remaining trigger file is deleted >> > in early warm-standby as a side-effect of this idea. >> >> Here is the revised patch as above. >> >> If you notice something, please feel free to comment. > > Deleting the trigger file when we request a history file works in most > cases, but not in all. We also request a history file when we switch > timelines, so code comments need slight modification. > > If take a base backup, switchover and then try to regen the primary from > the base backup we would need to switch timelines, which could be > problematic. That is unlikely, so we should at least very clearly > document the actual behaviour, as we do in the code comments. "switch timelines" means that a new timeline ID is assigned at the end of archive recovery? If so, even in this case, there is no problem with deleting the trigger file, I think. Or, am I misunderstanding? > I think your wording that smart mode guarantees no data will be lost is > a little strong. I'd say "on successful completion all WAL records will > be replayed resulting in zero data loss". Sounds good. I'll change the wording. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers