Return-Path: Delivered-To: apmail-tomcat-users-archive@www.apache.org Received: (qmail 18536 invoked from network); 21 Nov 2008 11:45:53 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 21 Nov 2008 11:45:53 -0000 Received: (qmail 42169 invoked by uid 500); 21 Nov 2008 11:45:46 -0000 Delivered-To: apmail-tomcat-users-archive@tomcat.apache.org Received: (qmail 42118 invoked by uid 500); 21 Nov 2008 11:45:45 -0000 Mailing-List: contact users-help@tomcat.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: "Tomcat Users List" Delivered-To: mailing list users@tomcat.apache.org Received: (qmail 42107 invoked by uid 99); 21 Nov 2008 11:45:45 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 21 Nov 2008 03:45:45 -0800 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [212.85.38.174] (HELO popeye.combios.es) (212.85.38.174) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 21 Nov 2008 11:44:21 +0000 Received: from [192.168.250.50] (p549EA79D.dip0.t-ipconnect.de [84.158.167.157]) (authenticated bits=0) by popeye.combios.es (8.13.8/8.13.8/Debian-3) with ESMTP id mALBeXCV024727 for ; Fri, 21 Nov 2008 12:40:34 +0100 Message-ID: <49269D99.7080504@ice-sa.com> Date: Fri, 21 Nov 2008 12:38:01 +0100 From: =?ISO-8859-1?Q?Andr=E9_Warnier?= User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Tomcat Users List Subject: Re: Tomcat threads, II References: <491AC9DC.5070900@ice-sa.com> <491B5787.6060004@iki.fi> In-Reply-To: <491B5787.6060004@iki.fi> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on popeye.combios.es X-Virus-Scanned: ClamAV 0.92.1/8657/Fri Nov 21 06:10:10 2008 on popeye.combios.es X-Virus-Status: Clean X-Virus-Checked: Checked by ClamAV on apache.org X-Old-Spam-Status: No, score=-97.9 required=2.5 tests=RCVD_IN_PBL, RCVD_IN_SORBS_DUL,USER_IN_WHITELIST autolearn=no version=3.2.3 Hi. To implement a recommendation from someone on this list, I took a few snapshots using "jmap -heap " while Tomcat was starting up and also starting up a webapp. I just ran the jmap command several times at about 5 second intervals, and redirected the output to a file. Below if the file content. What I would like to know now, is how I interpret these numbers. Is there somewhere a tutorial giving some pointers as to what I am looking at ? Or, does anyone feel like making some comments on the data below ? As a slightly narrower question, how do some of the numbers below relate to JVM startup parameters such as -Xms, -Xmx, and/or GC-related parameters ? And, is there somewhere I could find a description of terms used below, such as "Eden", "New Generation", "Perm Generation" etc.. ? Thanks in advance. Output of "jmap" : using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 14485952 (13.81488037109375MB) free = 1701440 (1.62261962890625MB) 89.48910361842105% used Eden Space: capacity = 14417920 (13.75MB) used = 12716480 (12.12738037109375MB) free = 1701440 (1.62261962890625MB) 88.1991299715909% used From Space: capacity = 1769472 (1.6875MB) used = 1769472 (1.6875MB) free = 0 (0.0MB) 100.0% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 109058784 (104.00656127929688MB) free = 34317600 (32.727813720703125MB) 76.06467742972232% used Perm Generation: capacity = 16777216 (16.0MB) used = 9495520 (9.055633544921875MB) free = 7281696 (6.944366455078125MB) 56.59770965576172% used using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 7146784 (6.815704345703125MB) free = 9040608 (8.621795654296875MB) 44.15031155111336% used Eden Space: capacity = 14417920 (13.75MB) used = 5377320 (5.128211975097656MB) free = 9040600 (8.621788024902344MB) 37.29608709161932% used From Space: capacity = 1769472 (1.6875MB) used = 1769464 (1.6874923706054688MB) free = 8 (7.62939453125E-6MB) 99.99954788773148% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 98216248 (93.66631317138672MB) free = 45160136 (43.06806182861328MB) 68.50238878949548% used Perm Generation: capacity = 16777216 (16.0MB) used = 9495520 (9.055633544921875MB) free = 7281696 (6.944366455078125MB) 56.59770965576172% used using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 15972760 (15.232810974121094MB) free = 214632 (0.20468902587890625MB) 98.67407918459008% used Eden Space: capacity = 14417920 (13.75MB) used = 14203296 (13.545318603515625MB) free = 214624 (0.204681396484375MB) 98.51140802556819% used From Space: capacity = 1769472 (1.6875MB) used = 1769464 (1.6874923706054688MB) free = 8 (7.62939453125E-6MB) 99.99954788773148% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 138744856 (132.3174057006836MB) free = 4631528 (4.416969299316406MB) 96.76967163574163% used Perm Generation: capacity = 16777216 (16.0MB) used = 9495616 (9.05572509765625MB) free = 7281600 (6.94427490234375MB) 56.59828186035156% used using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 1958368 (1.867645263671875MB) free = 14229024 (13.569854736328125MB) 12.098106971153847% used Eden Space: capacity = 14417920 (13.75MB) used = 288528 (0.2751617431640625MB) free = 14129392 (13.474838256835938MB) 2.0011763139204546% used From Space: capacity = 1769472 (1.6875MB) used = 1669840 (1.5924835205078125MB) free = 99632 (0.0950164794921875MB) 94.36939380787037% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 110665056 (105.53842163085938MB) free = 32711328 (31.195953369140625MB) 77.18499582190607% used Perm Generation: capacity = 16777216 (16.0MB) used = 9495616 (9.05572509765625MB) free = 7281600 (6.94427490234375MB) 56.59828186035156% used using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 11620976 (11.082626342773438MB) free = 4566416 (4.3548736572265625MB) 71.79029209893724% used Eden Space: capacity = 14417920 (13.75MB) used = 9851504 (9.395126342773438MB) free = 4566416 (4.3548736572265625MB) 68.32819158380681% used From Space: capacity = 1769472 (1.6875MB) used = 1769472 (1.6875MB) free = 0 (0.0MB) 100.0% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 143291656 (136.65357208251953MB) free = 84728 (0.08080291748046875MB) 99.94090519119244% used Perm Generation: capacity = 16777216 (16.0MB) used = 9495616 (9.05572509765625MB) free = 7281600 (6.94427490234375MB) 56.59828186035156% used using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 11288952 (10.765983581542969MB) free = 4898440 (4.671516418457031MB) 69.73916490068319% used Eden Space: capacity = 14417920 (13.75MB) used = 10963768 (10.455863952636719MB) free = 3454152 (3.2941360473632812MB) 76.04264692826705% used From Space: capacity = 1769472 (1.6875MB) used = 325184 (0.31011962890625MB) free = 1444288 (1.37738037109375MB) 18.37745949074074% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 96137256 (91.68363189697266MB) free = 47239128 (45.050743103027344MB) 67.05236477438292% used Perm Generation: capacity = 16777216 (16.0MB) used = 9495616 (9.05572509765625MB) free = 7281600 (6.94427490234375MB) 56.59828186035156% used using thread-local object allocation. Mark Sweep Compact GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 268435456 (256.0MB) NewSize = 655360 (0.625MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 1441792 (1.375MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 16187392 (15.4375MB) used = 1835928 (1.7508773803710938MB) free = 14351464 (13.686622619628906MB) 11.341715824266194% used Eden Space: capacity = 14417920 (13.75MB) used = 705984 (0.67327880859375MB) free = 13711936 (13.07672119140625MB) 4.896573153409091% used From Space: capacity = 1769472 (1.6875MB) used = 1129944 (1.0775985717773438MB) free = 639528 (0.6099014282226562MB) 63.857693142361114% used To Space: capacity = 1769472 (1.6875MB) used = 0 (0.0MB) free = 1769472 (1.6875MB) 0.0% used tenured generation: capacity = 143376384 (136.734375MB) used = 98726496 (94.15292358398438MB) free = 44649888 (42.581451416015625MB) 68.85826887641413% used Perm Generation: capacity = 16777216 (16.0MB) used = 10651600 (10.158157348632812MB) free = 6125616 (5.8418426513671875MB) 63.48848342895508% used --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org For additional commands, e-mail: users-help@tomcat.apache.org