Hi, this post is quite old, but I would like to share some recen developments.
I applied the recommandation. my process became: expunge deletes and optimize 2 segments. at the time I was with lucene 3.1 and that solved my issue. recently I moved to lucene 3.3, and I tried playing with the new tiered merge policy. what I found was that after an expunge, the number of deleted docs would stay the same, and space would not be reclaimed on the disk. I switched back to the default merge policy (LogByteSizeMergePolicy: minMergeSize=1677721, mergeFactor=10, maxMergeSize=2147483648, maxMergeSizeForOptimize=9223372036854775807, calibrateSizeByDeletes=true, maxMergeDocs=2147483647, useCompoundFile=true, noCFSRatio=0.1) and got this time the right behavior : size was reclaimed on disk. I even tried with the BalancedSegmentMergePolicy and got again the right behavior. so this issue seems to affect only the tiered merge policy. to illustrate this, I took an index with many deleted docs then expunged/optimized while using the tiered policy, then did the same thing with a default merge policy. here is for each step the content of the directory: before: 09.09.2011 17:38 20 segments.gen 09.09.2011 17:38 5'335 segments_4bf1u 06.09.2011 15:27 0 write.lock 06.09.2011 00:49 31'681'157'794 _jhwld.fdt 06.09.2011 00:49 115'562'268 _jhwld.fdx 06.09.2011 00:37 5'347 _jhwld.fnm 06.09.2011 01:13 7'147'947'472 _jhwld.frq 06.09.2011 01:13 3'927'649'164 _jhwld.prx 06.09.2011 01:13 41'992'760 _jhwld.tii 06.09.2011 01:13 3'745'729'056 _jhwld.tis 09.09.2011 00:27 1'805'669 _jhwld_3.del 09.09.2011 00:31 11'397'619'448 _jtrwg.fdt 09.09.2011 00:31 98'393'316 _jtrwg.fdx 09.09.2011 00:27 5'347 _jtrwg.fnm 09.09.2011 00:47 5'146'273'732 _jtrwg.frq 09.09.2011 00:47 1'661'436'146 _jtrwg.prx 09.09.2011 00:47 23'950'194 _jtrwg.tii 09.09.2011 00:47 2'139'903'139 _jtrwg.tis 09.09.2011 07:39 94'471'867 _jugaa.cfs 09.09.2011 10:14 252'716'611 _juok2.cfs 09.09.2011 15:45 7'986'102 _jwuaq.cfs 09.09.2011 16:00 5'780'703 _jx45g.cfs 09.09.2011 16:00 333'981'384 _jx46a.cfs 09.09.2011 16:23 20'955'761 _jxge0.cfs 09.09.2011 16:46 19'258'025 _jxmas.cfs 09.09.2011 16:55 16'622'800 _jxpv4.cfs 09.09.2011 17:10 14'605'028 _jxvd6.cfs 09.09.2011 17:34 12'456'476 _jy28o.cfs 09.09.2011 17:38 2'584'950 _jy91y.cfs 09.09.2011 17:38 2'595'049 _jy92i.cfs 09.09.2011 17:38 2'600'991 _jy932.cfs 09.09.2011 17:38 2'610'278 _jy93m.cfs 09.09.2011 17:38 46'664 _jy93x.cfs 09.09.2011 17:38 9'765 _jy93y.cfs 09.09.2011 17:38 10'691 _jy93z.cfs 09.09.2011 17:38 9'533 _jy940.cfs 09.09.2011 17:38 11'684 _jy941.cfs 09.09.2011 17:38 8'996 _jy942.cfs 38 File(s) 67'918'759'565 bytes after expunge/optimize (tiered merge policy): 09.09.2011 18:02 20 segments.gen 09.09.2011 18:02 3'171 segments_4bf3g 06.09.2011 15:27 0 write.lock 06.09.2011 00:49 31'681'157'794 _jhwld.fdt 06.09.2011 00:49 115'562'268 _jhwld.fdx 06.09.2011 00:37 5'347 _jhwld.fnm 06.09.2011 01:13 7'147'947'472 _jhwld.frq 06.09.2011 01:13 3'927'649'164 _jhwld.prx 06.09.2011 01:13 41'992'760 _jhwld.tii 06.09.2011 01:13 3'745'729'056 _jhwld.tis 09.09.2011 17:39 1'805'669 _jhwld_4.del 09.09.2011 17:45 11'814'367'373 _jy9iy.fdt 09.09.2011 17:45 101'565'036 _jy9iy.fdx 09.09.2011 17:39 5'347 _jy9iy.fnm 09.09.2011 18:01 5'328'530'169 _jy9iy.frq 09.09.2011 18:01 1'733'490'572 _jy9iy.prx 09.09.2011 18:01 25'072'713 _jy9iy.tii 09.09.2011 18:01 2'239'702'399 _jy9iy.tis 09.09.2011 18:02 185'962 _jy9mv.cfs 09.09.2011 18:02 9'955 _jy9mw.cfs 09.09.2011 18:02 10'380 _jy9mx.cfs 09.09.2011 18:02 9'341 _jy9my.cfs 09.09.2011 18:02 9'228 _jy9mz.cfs 09.09.2011 18:02 10'382 _jy9n0.cfs 09.09.2011 18:02 9'345 _jy9n1.cfs 09.09.2011 18:02 9'231 _jy9n2.cfs 09.09.2011 18:02 8'961 _jy9n3.cfs 09.09.2011 18:02 10'381 _jy9n4.cfs 09.09.2011 18:02 199'651 _jy9n5.cfs 09.09.2011 18:02 9'345 _jy9n6.cfs 09.09.2011 18:02 9'230 _jy9n7.cfs 31 File(s) 67'905'077'722 bytes after expungeDeletes/optimize with default merge policy : 09.09.2011 19:31 20 segments.gen 09.09.2011 19:31 2'081 segments_4bfpe 09.09.2011 18:13 0 write.lock 09.09.2011 18:42 30'133'772'814 _jyb4c.fdt 09.09.2011 18:42 103'164'812 _jyb4c.fdx 09.09.2011 18:27 5'347 _jyb4c.fnm 09.09.2011 19:03 6'474'023'590 _jyb4c.frq 09.09.2011 19:03 3'699'406'141 _jyb4c.prx 09.09.2011 19:03 37'900'657 _jyb4c.tii 09.09.2011 19:03 3'380'266'875 _jyb4c.tis 09.09.2011 19:15 11'820'477'088 _jyb4e.fdt 09.09.2011 19:15 101'659'700 _jyb4e.fdx 09.09.2011 19:03 5'347 _jyb4e.fnm 09.09.2011 19:29 5'333'219'797 _jyb4e.frq 09.09.2011 19:29 1'734'633'179 _jyb4e.prx 09.09.2011 19:29 25'105'023 _jyb4e.tii 09.09.2011 19:29 2'242'558'333 _jyb4e.tis 09.09.2011 19:31 223'600 _jyb5t.cfs 09.09.2011 19:31 9'545 _jyb5u.cfs 09.09.2011 19:31 8'963 _jyb5v.cfs 09.09.2011 19:31 9'250 _jyb5w.cfs 09.09.2011 19:31 9'047 _jyb5x.cfs 09.09.2011 19:31 11'253 _jyb5y.cfs 09.09.2011 19:31 11'239 _jyb5z.cfs 24 File(s) 65'086'483'701 bytes any clue to what is happenning? thanks, Vincent "Uwe Schindler" <u...@thetaphi.de> 21.07.2011 22:46 Please respond to java-user@lucene.apache.org To <java-user@lucene.apache.org> cc Subject RE: optimize with num segments > 1 index keeps growing There is also expungeDeletes()... ----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: v.se...@lombardodier.com [mailto:v.se...@lombardodier.com] > Sent: Thursday, July 21, 2011 8:39 PM > To: java-user@lucene.apache.org > Subject: Re: optimize with num segments > 1 index keeps growing > > Hi, thanks for this explanation. > so what is the best solution: merge the large segment (how can I do that) or > work with many segments (10?) so that I will avoid have this "large segment" > issue? > thanks, > vince > > > Vincent Sevel > Lombard Odier Darier Hentsch & Cie > 11, rue de la Corraterie - 1204 Genève - Suisse T +41 22 709 3376 - F +41 22 709 > 3782 www.lombardodier.com > > > > > > > > Simon Willnauer <simon.willna...@googlemail.com> > > > 21.07.2011 20:06 > Please respond to > java-user@lucene.apache.org > > > > To > java-user@lucene.apache.org > cc > > Subject > Re: optimize with num segments > 1 index keeps growing > > > > > > > so the problem here is that you have one really big segment _52aho.* and > several smaller ones _7e0wz.*, _7e0xu.*, _7e1x5.* .... > if you optimize to 2 segmetns all the smaller segments are merged into one > but all the large segment remains untouched. This means that all deleted > documents in the large segment are not removed / freed while if you > optimized to one segment they are removed. In the single seg. > index there is no *.del file present meaning no deletes. Unless you merge > the large segment all you deleted documents are only marked as delete but > not yet removed. > > simon > > On Thu, Jul 21, 2011 at 5:50 PM, <v.se...@lombardodier.com> wrote: > > hi, > > closing after the 2 segments optimize does not change it. > > also I am running with lucene 3.1.0. > > cheers, > > vince > > > > > > > > > > > > > > > > > > > > Ian Lea <ian....@gmail.com> > > > > > > 21.07.2011 17:30 > > Please respond to > > java-user@lucene.apache.org > > > > > > > > To > > java-user@lucene.apache.org > > cc > > > > Subject > > Re: optimize with num segments > 1 index keeps growing > > > > > > > > > > > > > > A write.lock file with timestamp of 13:58 is in all the listings. The > > first thing I'd try is to add some IndexWriter.close() calls. > > > > > > -- > > Ian. > > > > > > > > On Thu, Jul 21, 2011 at 4:05 PM, <v.se...@lombardodier.com> wrote: > >> Hi, > >> > >> here is a concrete example. > >> > >> I am starting with an index that has 19017236 docs, which takes 58989 > Mb > >> on disk: > >> > >> 21.07.2011 15:21 20 segments.gen > >> 21.07.2011 15:21 2'974 segments_2acy4 > >> 21.07.2011 13:58 0 write.lock > >> 16.07.2011 02:21 33'445'798'886 _52aho.fdt > >> 16.07.2011 02:21 178'723'932 _52aho.fdx > >> 16.07.2011 01:58 5'002 _52aho.fnm > >> 16.07.2011 03:10 9'857'410'889 _52aho.frq > >> 16.07.2011 03:10 4'538'234'846 _52aho.prx > >> 16.07.2011 03:10 61'581'767 _52aho.tii > >> 16.07.2011 03:10 5'505'039'790 _52aho.tis > >> 21.07.2011 01:01 1'899'536 _52aho_5.del > >> 21.07.2011 01:05 4'222'206'034 _6t61z.fdt > >> 21.07.2011 01:05 21'424'556 _6t61z.fdx > >> 21.07.2011 01:01 5'002 _6t61z.fnm > >> 21.07.2011 01:12 1'170'370'187 _6t61z.frq > >> 21.07.2011 01:12 598'373'388 _6t61z.prx > >> 21.07.2011 01:12 7'574'912 _6t61z.tii > >> 21.07.2011 01:12 678'766'206 _6t61z.tis > >> 21.07.2011 13:46 1'458'592'058 _7d6me.cfs > >> 21.07.2011 13:48 15'702'654 _7dhgz.cfs > >> 21.07.2011 13:52 16'800'942 _7dphm.cfs > >> 21.07.2011 13:55 16'714'431 _7dxht.cfs > >> 21.07.2011 14:24 17'505'435 _7e0wz.cfs > >> 21.07.2011 14:24 5'875'852 _7e0xu.cfs > >> 21.07.2011 14:48 18'340'470 _7e1x5.cfs > >> 21.07.2011 15:19 16'978'564 _7e3ck.cfs > >> 21.07.2011 15:21 1'208'656 _7e3hv.cfs > >> 21.07.2011 15:21 19'361 _7e3hw.cfs > >> 28 File(s) 61'855'156'350 bytes > >> > >> I am doing a delete of some of the older documents. after the delete, > >> I commit then I optimize down to 2 segments. at the end of the > >> optimize > > the > >> index contains 18702510 docs (314727 were deleted) and it takes now > > 58975 > >> Mb on disk: > >> > >> 21.07.2011 15:37 20 segments.gen > >> 21.07.2011 15:37 524 segments_2acy6 > >> 21.07.2011 13:58 0 write.lock > >> 16.07.2011 02:21 33'445'798'886 _52aho.fdt > >> 16.07.2011 02:21 178'723'932 _52aho.fdx > >> 16.07.2011 01:58 5'002 _52aho.fnm > >> 16.07.2011 03:10 9'857'410'889 _52aho.frq > >> 16.07.2011 03:10 4'538'234'846 _52aho.prx > >> 16.07.2011 03:10 61'581'767 _52aho.tii > >> 16.07.2011 03:10 5'505'039'790 _52aho.tis > >> 21.07.2011 15:23 1'999'945 _52aho_6.del > >> 21.07.2011 15:31 5'194'848'138 _7e3hy.fdt > >> 21.07.2011 15:31 28'613'668 _7e3hy.fdx > >> 21.07.2011 15:25 5'002 _7e3hy.fnm > >> 21.07.2011 15:37 1'529'771'296 _7e3hy.frq > >> 21.07.2011 15:37 726'582'244 _7e3hy.prx > >> 21.07.2011 15:37 8'518'198 _7e3hy.tii > >> 21.07.2011 15:37 763'213'144 _7e3hy.tis > >> 18 File(s) 61'840'347'291 bytes > >> > >> as you can see, size on disk did not really change. at this point I > >> optimize down to 1 segment and at the end the index takes 48273 Mb on > >> disk: > >> > >> 21.07.2011 16:46 20 segments.gen > >> 21.07.2011 16:46 278 segments_2acy8 > >> 21.07.2011 13:58 0 write.lock > >> 21.07.2011 16:06 32'901'423'750 _7e3hz.fdt > >> 21.07.2011 16:06 149'582'052 _7e3hz.fdx > >> 21.07.2011 15:42 5'002 _7e3hz.fnm > >> 21.07.2011 16:46 8'608'541'177 _7e3hz.frq > >> 21.07.2011 16:46 4'392'616'115 _7e3hz.prx > >> 21.07.2011 16:46 50'571'856 _7e3hz.tii > >> 21.07.2011 16:46 4'515'914'658 _7e3hz.tis > >> 10 File(s) 50'618'654'908 bytes > >> > >> > >> this means that with the 1 segment optimize I was able to reclaim 10 > >> Gb > > on > >> disk that the 2 segments optimize could not achieve. > >> > >> how can this be explained? is that a normal behavior? > >> > >> thanks, > >> > >> vince > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> Simon Willnauer <simon.willna...@googlemail.com> > >> > >> > >> 20.07.2011 23:11 > >> Please respond to > >> java-user@lucene.apache.org > >> > >> > >> > >> To > >> java-user@lucene.apache.org > >> cc > >> > >> Subject > >> Re: optimize with num segments > 1 index keeps growing > >> > >> > >> > >> > >> > >> > >> On Wed, Jul 20, 2011 at 2:00 PM, <v.se...@lombardodier.com> wrote: > >>> Hi, > >>> > >>> I index several millions small documents per day. each day, I remove > >> some > >>> of the older documents to keep the index at a stable number of > >> documents. > >>> after each purge, I commit then I optimize the index. what I found > >>> is > >> that > >>> if I keep optimizing with max num segments = 2, then the index keeps > >>> growing on the disk. but as soon as I optimize with just 1 segment, > the > >>> space gets reclaimed on the disk. so, I have currently adopted the > >>> following strategy : every night I optimize with 2 segments, except > > once > >>> per week where I optimize with just 1 segment. > >> > >> what do you mean by keeps growing. you have n segments and you > >> optimize down to 2 and the index is bigger than the one with n > >> segments? > >> > >> simon > >>> > >>> is that an expected behavior? > >>> I guess I am doing something special because I was not able to > > reproduce > >>> this behavior in a unit test. what could it be? > >>> > >>> it would be nice to get some explanatory services within the product > to > >>> help get some understanding on its behavior. something that tells > >>> you > >> some > >>> information about your index for instance (number of docs in the > >> different > >>> states, how the space is being used, ...). lucene is a wonderful > >> product, > >>> but to me this is almost like black magic, and when there is a > specific > >>> behavior, I have got little clues to figure out something by myself. > >> some > >>> user oriented logging would be nice as well (the index writer info > >> stream > >>> is really verbose and very low level). > >>> > >>> thanks for your help, > >>> > >>> > >>> Vince > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > > > > > > ************************ DISCLAIMER > ************************ This > > message is intended only for use by the person to whom it is > > addressed. 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