Re: pg_standby, Restartable Recovery after Hard Failure

On Wed, 2007-04-18 at 18:11 -0500, Thomas F. O'Connell wrote:
> Wanting a nice test of restartable recovery and pg_standby in a warm
> standby server scenario I'm testing, today I pulled the plug on the
> box where I was using Simon's test_warm_standby test harness.
> Basically, in this scenario, I had one posgres cluster (primary)
> against which pgbench was being run and a separate cluster (standby)
> that had been created from a base backup and then put into continuous
> recovery using pg_standby. In the middle of this scenario, I literally
> pulled the plug.

> If anyone can shed light on what might've happened in the hard failure
> scenario, I'd be interested to know. I've kept the various archive,
> primary, and standby directories created by test_warm_standby, so I
> can report on any file contents.

There is a possible error situation that I recently posted a fix to for
8.3. If you use the -k option with a low value then pg_standby can
delete files from the archive too quickly, so that when it tries to
return to the last restartpoint the file for that is missing.

The fix posted passes a new %r parameter to pg_standby, allowing it to
avoid deleting files too early.

If that doesn't explain your situation please send me logfiles etc
off-list so I can examine the details some more. Thanks.

> It occurs to me that timestamp information might be nice to have in
> pg_standby with debug mode. I might try patching pg_standby.c if no
> one beats me to it.

I'll look at doing this.

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com