(Five minutes at least has a defensible rationale, ie it's the default> checkpoint interval and we expect we can replay the log at least as> fast as it was created initially.)

Hmm, I remember Mark Wong from OSDL saying that it took to replay the> logs after a crash more than the six hours it had taken to generate> them.

When starting as a service at boot time on Windows, pg_autovacuum may>fail to start because the PostgreSQL service is still starting up. This>patch causes the service to attempt a second connection 30 seconds after>the initial connection failure before giving up entirely.>

Alvaro Herrera <alvherre@dcc.uchil­e.cl> writes:>> On Mon, Jan 24, 2005 at 06:57:54PM -0500, Tom Lane wrote:>>> (Five minutes at least has a defensible rationale, ie it's the default>>> checkpoint interval and we expect we can replay the log at least as>>> fast as it was created initially.)>

Six hours? Did he have checkpoints disabled somehow?

In the windows service world, is there any reason pg_autovacuum should > ever give up? The reason I had it give up was so that it didn't > accidently run against a different postgresql instance. I don't think > that will happen in the windows service world. I think it should keep > trying to do it's job until it's told to exit.

-----Original Message-----> From: Tom Lane [mailto:tgl@sss.pgh.pa.us] > Sent: 24 January 2005 23:58> To: Dave Page> Cc: pgsql-patches@postg­resql.org> Subject: Re: [PATCHES] pg_autovacuum Win32 Service startup delay >

"Dave Page" <dpage@vale-housing­.co.uk> writes:> > When starting as a service at boot time on Windows, > pg_autovacuum may> > fail to start because the PostgreSQL service is still > starting up. This> > patch causes the service to attempt a second connection 30 > seconds after> > the initial connection failure before giving up entirely.>

Hm. In event that the system crashed beforehand, it could > require much> more than 30 seconds to finish replaying the old WAL log. So > the above> doesn't seem super robust to me. Would it be reasonable to > try every 30> seconds for five minutes, or some such? (Five minutes at least has a> defensible rationale, ie it's the default checkpoint interval and we> expect we can replay the log at least as fast as it was created> initially.)

"Matthew T. O'Connor" <matthew@zeut.net> writes:>

I was a bit worried about the scenario in which J Random Luser tries to>start the server twice and ends up with two autovacuum daemons attached>to the same postmaster. I'm not sure if this is possible, probable,>or dangerous ... but it seems like a point to consider.>

It is a good point to consider. Let me be a little more detailed in my > explanation and see if that helps:> * A never give up pg_autovacuum would only be used when run as a windows > service.> * The windows service control manager can still kill pg_autovacuum, so > you shouldn't be able to start more than one that way.> * You have always been able to run multiple pg_autovacuums, it's not > advisable, and it's only bad side effect would be excessive, or more > than expected, vacuum commands.