Message-ID: <46A6C080.10204@denninger.net>
Date: Tue, 24 Jul 2007 22:16:16 -0500
From: Karl Denninger <karl@denninger.net>
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To: Merlin Moncure <mmoncure@gmail.com>
CC: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-performance@postgresql.org
Subject: Re: Performance issue with 8.2.3 - "C" application
References: <46A6A549.1040606@denninger.net> <29633.1185331558@sss.pgh.pa.us>	
	<46A6BBB1.1020502@denninger.net>
	<b42b73150707242015k615c7018s75cc0b804dbb5677@mail.gmail.com>
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Hmmmmm..... now that's interesting.  Stats collector IS accumulating 
quite a bit of runtime..... me thinks its time to go grab 8.2.4.

Karl Denninger (karl@denninger.net)
http://www.denninger.net


Merlin Moncure wrote:
> On 7/25/07, Karl Denninger <karl@denninger.net> wrote:
>>
>>  Yeah, the problem doesn't appear to be there.  As I said, if I look 
>> at the
>> PS of the system when its bogging, there aren't a whole bunch of 
>> processes
>> stuck doing these, so while this does take a second or two to come back,
>> that's not that bad.
>>
>>  Its GENERAL performance that just bites - the system is obviously 
>> out of
>> CPU, but what I can't get a handle on is WHY.  It does not appear to be
>> accumulating large amounts of runtime in processes I can catch, but 
>> the load
>> average is quite high.
>
> 8.2.3 has the 'stats collector bug' (fixed in 8.2.4) which increased
> load in high concurrency conditions.  on a client's machine after
> patching the postmaster load drop from the 4-5 range to 1-2 range on a
> 500 tps server.  maybe this is biting you?  symptoms are high load avg
> and high cpu usage of stats collector process.
>
> merlin
>
>
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