X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 99AC69DC9D1 for ; Thu, 9 Mar 2006 16:10:50 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 55143-05 for ; Thu, 9 Mar 2006 16:10:48 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id DAE659DC97E for ; Thu, 9 Mar 2006 16:10:44 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id k29KAhto027203; Thu, 9 Mar 2006 15:10:43 -0500 (EST) To: Jan de Visser cc: pgsql-performance@postgresql.org Subject: Re: Hanging queries on dual CPU windows In-reply-to: <200603091507.04663.jdevisser@digitalfairway.com> References: <200603060938.00751.jdevisser@digitalfairway.com> <200603091507.04663.jdevisser@digitalfairway.com> Comments: In-reply-to Jan de Visser message dated "Thu, 09 Mar 2006 15:07:04 -0500" Date: Thu, 09 Mar 2006 15:10:43 -0500 Message-ID: <27202.1141935043@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.112 required=5 tests=[AWL=0.112] X-Spam-Score: 0.112 X-Spam-Level: X-Archive-Number: 200603/99 X-Sequence-Number: 17536 Jan de Visser writes: > Furtermore, it does not happen on Linux machines, both single CPU and dual > CPU, nor on single CPU windows machines. We can only reproduce on a dual CPU > windows machine, and if we take one CPU out, it does not happen. > ... > Which showed me that several transactions where waiting for a particular row > which was locked by another transaction. This transaction had no pending > locks (so no deadlock), but just does not complete and hence never > relinquishes the lock. Is the stuck transaction still consuming CPU time, or just stopped? Is it possible to get a stack trace from the stuck process? I dunno if you've got anything gdb-equivalent under Windows, but that's the first thing I'd be interested in ... regards, tom lane