Received: from localhost (unknown [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 3DA672E3AB6 for ; Wed, 16 Jan 2008 11:30:55 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 16127-01-3 for ; Wed, 16 Jan 2008 11:30:50 -0400 (AST) Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.224]) by postgresql.org (Postfix) with ESMTP id 2EF0F2E34E6 for ; Wed, 16 Jan 2008 11:30:50 -0400 (AST) Received: by wx-out-0506.google.com with SMTP id r21so114343wxc.28 for ; Wed, 16 Jan 2008 07:30:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=i7u/+gZYIk0LBpKr/itFIxo9/4ttu4N2qLO7R+eu0WY=; b=UYVRiYaeA+o8V6Sh8/tYf2FGbSj2nIB1XnpWZe50KpYn/qUHgp39MdtSnajEg+bhxz7DnL7egtyXAPToN2a3ABJcZcPqsDzGmjmSo3k7BgwBWhbDxNm15YqVk2yIz6z6aCJnAet1kNZ20tGbWrZfT35h1sWv0fFjRNWHHmDPw5w= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=V9Ijo/dzvrWpCN51fkKU6OO0AKTmSKS/GfPXelgMAzmb64LnCxJ7+1DVQ6x8/HRfPlPN+h0Er3fAnI02+3NpPkPLpg1t5lJWnBGRSb64PzHtrW1c4j+/Rk7dKLuaPOXLwvogpXVKdW2F13syH+gHGt1YMXVbIm5awL/L0nO29Ww= Received: by 10.114.194.1 with SMTP id r1mr1066459waf.40.1200497448213; Wed, 16 Jan 2008 07:30:48 -0800 (PST) Received: by 10.114.133.5 with HTTP; Wed, 16 Jan 2008 07:30:48 -0800 (PST) Message-ID: Date: Wed, 16 Jan 2008 09:30:48 -0600 From: "Scott Marlowe" To: "Adrian Moisey" Subject: Re: strange pauses Cc: pgsql-performance@postgresql.org In-Reply-To: <478DDF83.8070106@careerjunction.co.za> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <478DDF83.8070106@careerjunction.co.za> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200801/134 X-Sequence-Number: 28373 On Jan 16, 2008 4:42 AM, Adrian Moisey wrote: > Hi > > I've noticed a strange pattern in our logs. > > We only log anything that takes longer then 5 seconds. > > If I tail the logs, I see a steady stream of functions that took longer > then 5 seconds. But every now and then I see nothing for 3 minutes and > after that a whole bunch (about 20 - 30) queries all finishing at the > same second. > > During this 3 minutes of nothing being logged, the db is still active > and I can access our website > > Looks to me like "something" is "locking" and causing requests to be > delayed. Once this "lock" unlocks, everything goes through. Hmmm. Are these queries actually all finishing at the same time or just showing up in the logs at the same time. Just thinking there might be some kind of issue going on with logging. Are you using syslog or postgresql stderr logging?