collector/autovacuum after crash (8.1beta3)

Started by Szima Gáborabout 20 years ago3 messages
#1Szima Gábor
sygma@tesla.hu

Hi All,

At system crash or poweroff the autovacuum statistics will be lost,
because this statistics only stored in RAM and saved/restored at
service shutdown/startup.
I think it should be saved periodically and not to be deleted after
crash.

-Sygma

#2Alvaro Herrera
alvherre@alvh.no-ip.org
In reply to: Szima Gábor (#1)
Re: collector/autovacuum after crash (8.1beta3)

Szima G�bor wrote:

At system crash or poweroff the autovacuum statistics will be lost,
because this statistics only stored in RAM and saved/restored at
service shutdown/startup.
I think it should be saved periodically and not to be deleted after
crash.

I don't remember why it was that we made the stat file be dropped on
crash recovery, but there was a reason. I guess you could research the
reason; it was a thread which ended with an autovacuum patch from me.
You could look the CVS logs for the pgstat.c file.

--
Alvaro Herrera http://www.advogato.org/person/alvherre
"Someone said that it is at least an order of magnitude more work to do
production software than a prototype. I think he is wrong by at least
an order of magnitude." (Brian Kernighan)

#3Tom Lane
tgl@sss.pgh.pa.us
In reply to: Alvaro Herrera (#2)
Re: collector/autovacuum after crash (8.1beta3)

Alvaro Herrera <alvherre@alvh.no-ip.org> writes:

Szima G�bor wrote:

At system crash or poweroff the autovacuum statistics will be lost,

I don't remember why it was that we made the stat file be dropped on
crash recovery, but there was a reason.

The fact that it's not WAL-backed and hence couldn't be trusted. But
I think he's complaining about the contrib version of autovacuum anyway.

regards, tom lane