From kato-dev-return-297-apmail-incubator-kato-dev-archive=incubator.apache.org@incubator.apache.org Thu Jan 14 10:29:27 2010 Return-Path: Delivered-To: apmail-incubator-kato-dev-archive@minotaur.apache.org Received: (qmail 44377 invoked from network); 14 Jan 2010 10:29:27 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 14 Jan 2010 10:29:27 -0000 Received: (qmail 45403 invoked by uid 500); 14 Jan 2010 10:29:27 -0000 Delivered-To: apmail-incubator-kato-dev-archive@incubator.apache.org Received: (qmail 45368 invoked by uid 500); 14 Jan 2010 10:29:27 -0000 Mailing-List: contact kato-dev-help@incubator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: kato-dev@incubator.apache.org Delivered-To: mailing list kato-dev@incubator.apache.org Received: (qmail 45358 invoked by uid 99); 14 Jan 2010 10:29:27 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 14 Jan 2010 10:29:27 +0000 X-ASF-Spam-Status: No, hits=2.2 required=10.0 tests=HTML_MESSAGE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of spoole167@googlemail.com designates 209.85.218.210 as permitted sender) Received: from [209.85.218.210] (HELO mail-bw0-f210.google.com) (209.85.218.210) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 14 Jan 2010 10:29:16 +0000 Received: by bwz2 with SMTP id 2so15596075bwz.20 for ; Thu, 14 Jan 2010 02:28:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=XT1YraCO0+IsbnDsB2MJVuF1Qj8Z3cxerPcnZCX+uZI=; b=lZiCCPfrOewlh2uy82ZgI0B4DTnYi4oUIjNZt73RPR23oASB8tiujiCUX6v/kVcs1y ku3QaGl/utyhaZ0T7xNH+WbQe6A7dieb8+vXaqfzPWVRJVLAjlRg2xqd5V31muKu5BQY nZZajElzYHtMHvsAkcqvIchccJ/Ng3sgoqCbc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=kpELpgiSQ0zbQwFX7tW9LruSN24I8s8vMUtG6WF5YgA0gDSTlM7qeBObtEelexT9gD DbeYw0DFSeoWQE/HBtVMS3UVLZLx5tu3YO76LEiBQLUapfKdJUClXQYJyaec/mkZXD9J dKbIDtA8miABfhW8+iGd24Iy0qhnlKQS4FP2U= MIME-Version: 1.0 Received: by 10.204.139.23 with SMTP id c23mr320702bku.112.1263464935752; Thu, 14 Jan 2010 02:28:55 -0800 (PST) In-Reply-To: <4B4CBCB1.3070009@stoo.me.uk> References: <4B47835B.2030904@intercel.com.pl> <4B4A317C.2040900@stoo.me.uk> <4B4B9140.5090106@intercel.com.pl> <4B4CB631.1010503@intercel.com.pl> <4B4CBCB1.3070009@stoo.me.uk> Date: Thu, 14 Jan 2010 10:28:55 +0000 Message-ID: Subject: Re: Processing huge heap dump. From: Steve Poole To: kato-dev@incubator.apache.org Content-Type: multipart/alternative; boundary=0015174c0c38ae82a2047d1d5a29 X-Virus-Checked: Checked by ClamAV on apache.org --0015174c0c38ae82a2047d1d5a29 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Lukasz, You say your hprof format is 1.0.1 so , according to the information I have about hprof format, that means your won't have any heap dump segments in your file. Apparently they are in the 1.0.2 format which is a Java 6 addition and is only used when the heap is too big for the old format to cope with. What JVM and OS are you using to produce this dump? On Tue, Jan 12, 2010 at 6:17 PM, Stuart Monteith wrote= : > Hi, > > > You are quite right, 4 bytes for the record length. If we had the file > format wrong for 64 bit > hprof dumps we'd not be able to read any dump, so it must be an overflow = of > the record length. > In that case, the only possible solution I can think of would be for us t= o > change to code to search > for the HEAP DUMP END record (tagged 0x2c) to detect the end of the HEAP > DUMP. > > Of course, there was some puzzling over the difference between HEAP DUMP > SEGMENT (0x1c) and HEAP DUMP > (0x0c) before. > > I'd expect we'd get: > > HEAP DUMP > heap dump records.... > HEAP DUMP END > > or > > HEAP DUMP SEGMENT > heap dump records > HEAP DUMP SEGMENT > heap dump records > : : > HEAP DUMP END > > > If we ignore the record size for the HEAP DUMP and calculate it ourselves= , > we might have more luck. > > Regards, > Stuart > > > > Lukasz wrote: > >> Hello, >> >> Since performance looks not bad after changing array size, today I have >> tried to process my 60GB heap dump. Unfortunately, very fast I've ended = with >> exception: >> Exception in thread "main" java.lang.IllegalArgumentException: range >> -1293366370 is less than 0 >> at >> org.apache.kato.common.SubsetDataProvider.(SubsetDataProvider.java= :29) >> >> at >> org.apache.kato.hprof.datalayer.HProfFile$HPROFRecordProvider.getCurrent= Element(HProfFile.java:487) >> >> at >> org.apache.kato.hprof.datalayer.HProfFile$HPROFRecordProvider.getCurrent= Element(HProfFile.java:437) >> >> at >> org.apache.kato.common.BitMaskMappingArray.get(BitMaskMappingArray.java:= 56) >> at org.apache.kato.hprof.datalayer.HProfFile.getRecord(HProfFile.java:78= 4) >> ... (my code) ... >> >> It looks like range of HeapDumpHProfRecord had value: -1293366370. >> >> Following is the part of the dump which I believes is responsible for th= at >> (B2 E8 CB 9E): >> 0055DD84 25 00 00 2A =E2=94=82 B7 AE 22 06 =E2=94=82 80 00 00 00 =E2=94= =82 01 00 00 2A =E2=94=82 B7 AE 20 >> 0B =E2=94=82 88 02 00 00 =E2=94=82 00 00 00 00 =E2=94=82 00 18 00 00 =E2= =94=82 23 26 00 00 >> 0055DDA8 2A B7 B0 A1 =E2=94=82 64 28 00 00 =E2=94=82 00 01 00 00 =E2=94= =82 2A B7 B0 33 =E2=94=82 EA F8 0C >> 00 =E2=94=82 00 00 00 B2 =E2=94=82 E8 CB 9E 20 =E2=94=82 00 00 2A B7 =E2= =94=82 B0 DE AF C8 >> 0055DDCC 00 00 00 01 =E2=94=82 00 00 2A B7 =E2=94=82 AE 22 0F 20 =E2=94= =82 00 00 2A AA =E2=94=82 BE 21 3D >> 28 =E2=94=82 00 00 00 00 =E2=94=82 00 00 00 00 =E2=94=82 00 00 2A AA =E2= =94=82 BE 25 B7 D8 >> >> What is interesting hprof file format reserves only 4 bytes for length o= f >> a record, which allows to express record whose size is at most 4GB (assu= ming >> unsigned 4 bytes). >> >> My dump's version is: JAVA PROFILE 1.0.1 >> >> Regards >> Lukasz >> >> >> Lukasz wrote: >> >>> Hi Stuart, Steve, >>> >>> I've taken deeper look into code. I still didn't trace carefully index >>> calculation in classes BitMaskMappingArray and ArrayBitMaskMappingStrat= egy, >>> but I managed to improve performance by increasing arrays size in those >>> classes (which is set in HProfFile class). >>> >>> If I understand code correctly, when capacity of BitMaskMappingArray wi= ll >>> be exhausted bucketSize is doubled, which in turn causes that more read= s >>> (even cached) is required to set position of >>> IDataProvider/IArrayEntryProvider. >>> >>> Following are loading time results for default array size (1000) and >>> increased (1000000). Test ran against generated dump file (5000000 inst= ances >>> of Data). >>> Default (1000): >>> HeapSubRecord: 100000 (866ms, 4215kB) >>> HeapSubRecord: 200000 (1716ms, 7879kB) >>> HeapSubRecord: 300000 (2833ms, 11263kB) >>> HeapSubRecord: 400000 (3889ms, 14283kB) >>> HeapSubRecord: 500000 (3893ms, 17319kB) >>> HeapSubRecord: 600000 (7248ms, 20479kB) (here probably buckedSize was >>> doubled) >>> HeapSubRecord: 700000 (7721ms, 23531kB) >>> HeapSubRecord: 800000 (7729ms, 26567kB) >>> HeapSubRecord: 900000 (7731ms, 29671kB) >>> HeapSubRecord: 1000000 (7704ms, 32731kB) >>> ... (I didn't wait until end) >>> >>> Increased(1000000): >>> HeapSubRecord: 100000 (622ms, 17809kB) >>> HeapSubRecord: 200000 (309ms, 20345kB) >>> HeapSubRecord: 300000 (283ms, 23861kB) >>> HeapSubRecord: 400000 (274ms, 27921kB) >>> HeapSubRecord: 500000 (269ms, 29957kB) >>> HeapSubRecord: 600000 (264ms, 31993kB) >>> HeapSubRecord: 700000 (272ms, 36097kB) >>> HeapSubRecord: 800000 (288ms, 37739kB) >>> HeapSubRecord: 900000 (263ms, 39835kB) >>> HeapSubRecord: 1000000 (259ms, 41931kB) >>> HeapSubRecord: 1100000 (300ms, 44773kB) >>> HeapSubRecord: 1200000 (283ms, 46901kB) >>> HeapSubRecord: 1300000 (291ms, 49029kB) >>> HeapSubRecord: 1400000 (328ms, 53801kB) >>> HeapSubRecord: 1500000 (259ms, 53801kB) >>> HeapSubRecord: 1600000 (272ms, 58125kB) >>> HeapSubRecord: 1700000 (264ms, 60293kB) >>> HeapSubRecord: 1800000 (264ms, 62473kB) >>> HeapSubRecord: 1900000 (361ms, 61373kB) >>> HeapSubRecord: 2000000 (274ms, 63105kB) >>> ... >>> HeapSubRecord: 9000000 (284ms, 231969kB) >>> HeapSubRecord: 9100000 (272ms, 233597kB) >>> HeapSubRecord: 9200000 (281ms, 236357kB) >>> HeapSubRecord: 9300000 (274ms, 240469kB) >>> HeapSubRecord: 9400000 (279ms, 244541kB) >>> HeapSubRecord: 9500000 (269ms, 246549kB) >>> HeapSubRecord: 9600000 (279ms, 250565kB) >>> HeapSubRecord: 9700000 (265ms, 252573kB) >>> HeapSubRecord: 9800000 (279ms, 256629kB) >>> HeapSubRecord: 9900000 (265ms, 258669kB) >>> HeapSubRecord: 10000000 (463ms, 263997kB) >>> (end) >>> >>> i.e. my 60GB dump file contains more than 1 100 000 000 of objects (if = I >>> remember correctly). >>> >>> Regards >>> Lukasz >>> >>> >>> Stuart Monteith wrote: >>> >>>> The hprof dump reader spends a lot of time reading the whole file, for >>>> various reason. >>>> The indices it has in memory are constructed through an initial read, >>>> and this is also >>>> the source of the memory usage. In addition, there is some correlation >>>> to be done which >>>> also takes up time, and induces yet more reading. >>>> >>>> I'm sure some work could be done to improve the performance further, b= ut >>>> we'll have to >>>> look at the tradeoff between diskspace and memory usage. The hprof fil= e >>>> format itself >>>> is what it is, however, and we have no influence over that. The CJVMTI >>>> agent is has lots of >>>> room for improvement, but I suspect its potential for improvement is >>>> unlikely to be much better >>>> than existing hprof implementations. The built-in JVM hprof dumper wil= l >>>> probably be a hard act >>>> to follow. >>>> >>>> The HProf implementation is not thread-safe. Realistically, I think it >>>> is something that ought to >>>> be considered once things are more mature. There will be algorithms th= at >>>> can deal with the JVM >>>> structure sensible. >>>> >>>> And thanks Lukasz, it's great to have your input. >>>> >>>> Regards, >>>> Stuart >>>> >>> >>> >> > -- > Stuart Monteith > http://blog.stoo.me.uk/ > > --=20 Steve --0015174c0c38ae82a2047d1d5a29--