On Sun, 2 Oct 2005, Simon Riggs wrote:
Probably the best idea is to backup the last WAL file for each timeline
seen. Keep track of that, so when the current file changes you'll know
which timeline you're on and stick to that from then on. Or more simply,
put some notes with your program saying "if you ever use a complex
recovery situation, make sure to clear all archive_status files for
higher timeline ids before using this program".
Tell me if you think this is the most reasonable way to determine the in use
WAL file:
ls -rt $PGDATA/pg_xlog/ | grep -v "backup\|archive\|RECOVERY" | tail -1
This would not be necessary had I completed my logswitch patch in time
for 8.1 freeze, but I regret that I was unable to do that.
What's the logswitch patch going to accomplish? Sounds interesting.
Also, I have an interesting and unrelated question...this past weekend, we had
a failure in which we had to restore from backup. I have created a script
which makes a base backup every two weeks and we keep the last two. Also, we
use PITR for replication, making a base backup between the primary and
secondary server every 8 hours, and running my rsynclastlog script once/minute
to keep as up to date as possible. Now here's the problem...the servers
switched roles on Sep 21. We switched them back a little while after that.
When I went to replay the WAL files using the Sep 15 base backup, it happily
played back the WAL files to Sep 21 and stopped. I presume that this means
whenever the servers switch roles I need to create a fresh base backup?
Is there any possible way to replay the other WAL files after the Sep 21
switchover/switchback? I'm going to guess this is similar to having another
timeline.
We restored from a nightly pg_dump which we have kept doing, but that means we
lost about 20 hrs of data. :-(
--
Jeff Frost, Owner <jeff@xxxxxxxxxxxxxxxxxxxxxx>
Frost Consulting, LLC http://www.frostconsultingllc.com/
Phone: 650-780-7908 FAX: 650-649-1954
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