From: Tobias Brox <tobias@nordicbet.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Tobias Brox <tobias@nordicbet.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: long running transactions
Date: Tue, 10 Oct 2006 19:49:55 +0200
Message-ID: <20061010174955.GA284@oppetid.no> (raw)
In-Reply-To: <26123.1160500707@sss.pgh.pa.us>
References: <20061010161027.GA18908@oppetid.no>
<25404.1160497420@sss.pgh.pa.us>
<20061010163913.GA8097@oppetid.no>
<20061010164142.GA5360@oppetid.no>
<25631.1160498572@sss.pgh.pa.us>
<20061010170639.GB5360@oppetid.no>
<25953.1160500192@sss.pgh.pa.us>
<20061010171304.GC5360@oppetid.no>
<26123.1160500707@sss.pgh.pa.us>
[Tom Lane - Tue at 01:18:27PM -0400]
> >> Hmph. Is the autovac process actually doing anything (strace would be
> >> revealing)?
It's definitively doing something; mostly reading, but also some few
writes, semops and opens.
> If not, can you attach to the autovac process with gdb and
> >> get a stack trace to see where it's blocked?
(gdb) bt
#0 0xb7c599f8 in select () from /lib/tls/libc.so.6
#1 0x08253c53 in pg_usleep ()
#2 0x0812ee93 in vacuum_delay_point ()
#3 0x0812f2a5 in lazy_vacuum_rel ()
#4 0x0812ef7b in lazy_vacuum_rel ()
#5 0x0812b4b6 in vac_update_relstats ()
#6 0x0812a995 in vacuum ()
#7 0x0818d2ca in autovac_stopped ()
#8 0x0818ceae in autovac_stopped ()
#9 0x0818c848 in autovac_stopped ()
#10 0x0818c4e2 in autovac_start ()
#11 0x08192c11 in PostmasterMain ()
#12 0x08191dcf in PostmasterMain ()
#13 0x081541b1 in main ()
> It'll come back after the autovacuum naptime. If it gets stuck again,
> please investigate.
It seems stuck, has had the same transid for a long while, and the
number of undeletable dead rows in our tables are increasing.
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To: pgsql-performance@postgresql.org
Cc: tobias@nordicbet.com, tgl@sss.pgh.pa.us
Subject: Re: long running transactions
In-Reply-To: <20061010174955.GA284@oppetid.no>
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