Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 623A59FB56F for ; Fri, 27 Jul 2007 17:05:05 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 65797-03 for ; Fri, 27 Jul 2007 17:04:58 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from brmea-mail-3.sun.com (brmea-mail-3.Sun.COM [192.18.98.34]) by postgresql.org (Postfix) with ESMTP id DB9EC9FB378 for ; Fri, 27 Jul 2007 17:05:00 -0300 (ADT) Received: from fe-amer-05.sun.com ([192.18.108.179]) by brmea-mail-3.sun.com (8.13.6+Sun/8.12.9) with ESMTP id l6RK4xga013660 for ; Fri, 27 Jul 2007 20:04:59 GMT Received: from conversion-daemon.mail-amer.sun.com by mail-amer.sun.com (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) id <0JLU00601QS30I00@mail-amer.sun.com> (original mail from J.K.Shah@Sun.COM) for pgsql-performance@postgresql.org; Fri, 27 Jul 2007 14:04:59 -0600 (MDT) Received: from [129.148.9.17] by mail-amer.sun.com (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPSA id <0JLU003LHT49LEB5@mail-amer.sun.com>; Fri, 27 Jul 2007 14:04:58 -0600 (MDT) Date: Fri, 27 Jul 2007 16:04:57 -0400 From: "Jignesh K. Shah" Subject: Re: User concurrency thresholding: where do I look? In-reply-to: <46AA4367.4020706@sun.com> To: "Jignesh K. Shah" Cc: Simon Riggs , Tom Lane , Josh Berkus , pgsql-performance@postgresql.org, Alvaro Herrera Message-id: <46AA4FE9.2030302@sun.com> Organization: Sun Microsystems MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7BIT References: <200707190828.59088.josh@agliodbs.com> <200707191819.13899.josh@agliodbs.com> <15685.1184895926@sss.pgh.pa.us> <200707192138.39679.josh@agliodbs.com> <46A0FA31.2080208@sun.com> <12002.1184955831@sss.pgh.pa.us> <46A1055F.9010304@sun.com> <12445.1184958793@sss.pgh.pa.us> <46A11116.5030905@sun.com> <14909.1184962561@sss.pgh.pa.us> <46A1205B.8010205@sun.com> <15343.1184965054@sss.pgh.pa.us> <1185180668.4284.149.camel@ebony.site> <23848.1185199901@sss.pgh.pa.us> <1185201556.4284.243.camel@ebony.site> <25095.1185202498@sss.pgh.pa.us> <1185205663.4284.249.camel@ebony.site> <1185212261.4284.270.camel@ebony.site> <1545.1185214760@sss.pgh.pa.us> <46A7D5AD.9000706@sun.com> <13162.1185405865@sss.pgh.pa.us> <46A8AFDF.3050804@sun.com> <26825.1185460816@sss.pgh.pa.us> <46A8BD62.2080904@sun.com> <1185465076.4190.87.camel@ebony.site> <46A8F9AA.4040507@sun.com> <1185480291.5510.22.camel@ebony.site> <46A90F83.8050401@sun.com> <1185527727.4191.22.camel@ebony.site> <46AA4367.4020706@sun.com> User-Agent: Thunderbird 1.5.0.8 (X11/20061110) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200707/391 X-Sequence-Number: 26075 Using CLOG Buffers 32 and the commit sibling check patch I still see a drop at 1200-1300 users.. bash-3.00# ./4_lwlock_waits.d 18250 Lock Id Mode Count XidGenLock Shared 1 CLogControlLock Shared 2 ProcArrayLock Shared 2 XidGenLock Exclusive 4 CLogControlLock Exclusive 15 WALInsertLock Exclusive 18 WALWriteLock Exclusive 38 ProcArrayLock Exclusive 77 Lock Id Mode Combined Time (ns) XidGenLock Shared 88700 WALInsertLock Exclusive 69556000 ProcArrayLock Shared 95656800 XidGenLock Exclusive 139634100 CLogControlLock Exclusive 148822200 CLogControlLock Shared 161630000 WALWriteLock Exclusive 332781800 ProcArrayLock Exclusive 5688265500 bash-3.00# ./4_lwlock_waits.d 18599 Lock Id Mode Count ProcArrayLock Shared 2 XidGenLock Exclusive 3 XidGenLock Shared 4 CLogControlLock Shared 5 WALInsertLock Exclusive 10 CLogControlLock Exclusive 21 WALWriteLock Exclusive 28 ProcArrayLock Exclusive 54 Lock Id Mode Combined Time (ns) XidGenLock Exclusive 5688800 WALInsertLock Exclusive 11424700 CLogControlLock Shared 55589100 ProcArrayLock Shared 135220400 WALWriteLock Exclusive 177906900 XidGenLock Shared 524146500 CLogControlLock Exclusive 524563900 ProcArrayLock Exclusive 5828744500 bash-3.00# bash-3.00# ./6_lwlock_stack.d 4 18599 Lock Id Mode Count ProcArrayLock Shared 1 ProcArrayLock Exclusive 52 Lock Id Mode Combined Time (ns) ProcArrayLock Shared 41428300 ProcArrayLock Exclusive 3858386500 Lock Id Combined Time (ns) postgres`LWLockAcquire+0x1f0 postgres`GetSnapshotData+0x120 postgres`GetTransactionSnapshot+0x80 postgres`PortalStart+0x198 postgres`exec_bind_message+0x84c postgres`PostgresMain+0x17f8 postgres`BackendRun+0x2f8 postgres`ServerLoop+0x680 postgres`PostmasterMain+0xda8 postgres`main+0x3d0 postgres`_start+0x17c Shared 41428300 postgres`LWLockAcquire+0x1f0 postgres`CommitTransaction+0x104 postgres`CommitTransactionCommand+0xbc postgres`finish_xact_command+0x78 postgres`exec_execute_message+0x42c postgres`PostgresMain+0x1838 postgres`BackendRun+0x2f8 postgres`ServerLoop+0x680 postgres`PostmasterMain+0xda8 postgres`main+0x3d0 postgres`_start+0x17c Exclusive 3858386500 -Jignesh