Re: Postgres Replaying WAL slowly

On 2014-06-30 19:14:24 +0300, Heikki Linnakangas wrote:
> On 06/30/2014 05:46 PM, Soni M wrote:
> >Here's what 'perf top' said on streaming replica :
> >
> >Samples: 26K of event 'cpu-clock', Event count (approx.): 19781
> > 95.97% postgres [.] 0x00000000002210f3
>
> Ok, so it's stuck doing something.. Can you get build with debug symbols
> installed, so that we could see the function name?

My guess it's a spinlock, probably xlogctl->info_lck via
RecoveryInProgress(). Unfortunately inline assembler doesn't always seem
to show up correctly in profiles...

What worked for me was to build with -fno-omit-frame-pointer - that
normally shows the callers, even if it can't generate a proper symbol
name.

Soni: Do you use Hot Standby? Are there connections active while you
have that problem? Any other processes with high cpu load?

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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