-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Thu, 13 Dec 2007 11:12:26 -0800 "Joshua D. Drake" <[EMAIL PROTECTED]> wrote:
> > > Hmm --- I was testing a straight crash-recovery scenario, not > > > restoring from archive. Are you sure your restore_command script > > > isn't responsible for a lot of the delay? > > > > Now that's an interesting thought, I will review in the morning when > > I have some more IQ points back. > > As promised :)... I took a look at this today and I think I found a > couple of things. It appears that once the logs are archived, the > recovery command copies the archive file to a recovery location and > then restores the file. > > If that is correct that could explain some of the latency I am seeing > here. Even with the speed of these devices, it is still a 16 MB file. > That could take 1-2 seconds to copy. > > There is also the execution of pg_standby each time as the recovery > command which although I haven't timed is going to add overhead. > > Based on the logs I pasted we are showing a delay of 6, 14, 3, 13, 4 > and then another 6 seconds. > > When are fsyncs called on the recovery process? > > At these types of delays even speeding the process 2 seconds per log > is going to be significant. > > Sincerely, > > Joshua D. Drake > - -- The PostgreSQL Company: Since 1997, http://www.commandprompt.com/ Sales/Support: +1.503.667.4564 24x7/Emergency: +1.800.492.2240 Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate SELECT 'Training', 'Consulting' FROM vendor WHERE name = 'CMD' -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFHYaoyATb/zqfZUUQRAozEAJ94sm3gdhPB0dcHfBD4uIs6cKHB4ACeK8dj Wh9Jw2N3Ac29ELPaPZJL/+w= =7edj -----END PGP SIGNATURE----- ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend