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Lucene/Solr QA commented on LUCENE-7976: ---------------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || || || || || {color:brown} Prechecks {color} || | {color:green}+1{color} | {color:green} test4tests {color} | {color:green} 0m 0s{color} | {color:green} The patch appears to include 1 new or modified test files. {color} | || || || || {color:brown} master Compile Tests {color} || | {color:green}+1{color} | {color:green} compile {color} | {color:green} 7m 27s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:green}+1{color} | {color:green} compile {color} | {color:green} 6m 58s{color} | {color:green} the patch passed {color} | | {color:red}-1{color} | {color:red} javac {color} | {color:red} 1m 49s{color} | {color:red} lucene_core generated 3 new + 1 unchanged - 0 fixed = 4 total (was 1) {color} | | {color:green}+1{color} | {color:green} Release audit (RAT) {color} | {color:green} 2m 27s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} Check forbidden APIs {color} | {color:green} 1m 49s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} Validate source patterns {color} | {color:green} 1m 49s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} Validate ref guide {color} | {color:green} 1m 49s{color} | {color:green} the patch passed {color} | || || || || {color:brown} Other Tests {color} || | {color:green}+1{color} | {color:green} unit {color} | {color:green} 43m 49s{color} | {color:green} core in the patch passed. {color} | | {color:red}-1{color} | {color:red} unit {color} | {color:red} 65m 50s{color} | {color:red} core in the patch failed. {color} | | {color:red}-1{color} | {color:red} unit {color} | {color:red} 13m 31s{color} | {color:red} solrj in the patch failed. {color} | | {color:black}{color} | {color:black} {color} | {color:black}148m 29s{color} | {color:black} {color} | \\ \\ || Reason || Tests || | Failed junit tests | solr.rest.TestManagedResourceStorage | | | solr.cloud.autoscaling.SearchRateTriggerIntegrationTest | | | solr.cloud.autoscaling.ScheduledMaintenanceTriggerTest | | | solr.client.solrj.impl.CloudSolrClientTest | | | solr.common.util.TestJsonRecordReader | \\ \\ || Subsystem || Report/Notes || | JIRA Issue | LUCENE-7976 | | JIRA Patch URL | https://issues.apache.org/jira/secure/attachment/12927680/LUCENE-7976.patch | | Optional Tests | compile javac unit ratsources checkforbiddenapis validatesourcepatterns validaterefguide | | uname | Linux lucene2-us-west.apache.org 4.4.0-112-generic #135-Ubuntu SMP Fri Jan 19 11:48:36 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux | | Build tool | ant | | Personality | /home/jenkins/jenkins-slave/workspace/PreCommit-LUCENE-Build/sourcedir/dev-tools/test-patch/lucene-solr-yetus-personality.sh | | git revision | master / 2db2fb3 | | ant | version: Apache Ant(TM) version 1.9.6 compiled on July 8 2015 | | Default Java | 1.8.0_172 | | javac | https://builds.apache.org/job/PreCommit-LUCENE-Build/33/artifact/out/diff-compile-javac-lucene_core.txt | | unit | https://builds.apache.org/job/PreCommit-LUCENE-Build/33/artifact/out/patch-unit-solr_core.txt | | unit | https://builds.apache.org/job/PreCommit-LUCENE-Build/33/artifact/out/patch-unit-solr_solrj.txt | | Test Results | https://builds.apache.org/job/PreCommit-LUCENE-Build/33/testReport/ | | modules | C: lucene/core solr/core solr/solrj solr/solr-ref-guide solr/webapp U: . | | Console output | https://builds.apache.org/job/PreCommit-LUCENE-Build/33/console | | Powered by | Apache Yetus 0.7.0 http://yetus.apache.org | This message was automatically generated. > Make TieredMergePolicy respect maxSegmentSizeMB and allow singleton merges of > very large segments > ------------------------------------------------------------------------------------------------- > > Key: LUCENE-7976 > URL: https://issues.apache.org/jira/browse/LUCENE-7976 > Project: Lucene - Core > Issue Type: Improvement > Reporter: Erick Erickson > Assignee: Erick Erickson > Priority: Major > Attachments: LUCENE-7976.patch, LUCENE-7976.patch, LUCENE-7976.patch, > LUCENE-7976.patch, LUCENE-7976.patch, LUCENE-7976.patch, LUCENE-7976.patch, > LUCENE-7976.patch, LUCENE-7976.patch, LUCENE-7976.patch, LUCENE-7976.patch, > LUCENE-7976.patch, SOLR-7976.patch > > > We're seeing situations "in the wild" where there are very large indexes (on > disk) handled quite easily in a single Lucene index. This is particularly > true as features like docValues move data into MMapDirectory space. The > current TMP algorithm allows on the order of 50% deleted documents as per a > dev list conversation with Mike McCandless (and his blog here: > https://www.elastic.co/blog/lucenes-handling-of-deleted-documents). > Especially in the current era of very large indexes in aggregate, (think many > TB) solutions like "you need to distribute your collection over more shards" > become very costly. Additionally, the tempting "optimize" button exacerbates > the issue since once you form, say, a 100G segment (by > optimizing/forceMerging) it is not eligible for merging until 97.5G of the > docs in it are deleted (current default 5G max segment size). > The proposal here would be to add a new parameter to TMP, something like > <maxAllowedPctDeletedInBigSegments> (no, that's not serious name, suggestions > welcome) which would default to 100 (or the same behavior we have now). > So if I set this parameter to, say, 20%, and the max segment size stays at > 5G, the following would happen when segments were selected for merging: > > any segment with > 20% deleted documents would be merged or rewritten NO > > MATTER HOW LARGE. There are two cases, > >> the segment has < 5G "live" docs. In that case it would be merged with > >> smaller segments to bring the resulting segment up to 5G. If no smaller > >> segments exist, it would just be rewritten > >> The segment has > 5G "live" docs (the result of a forceMerge or optimize). > >> It would be rewritten into a single segment removing all deleted docs no > >> matter how big it is to start. The 100G example above would be rewritten > >> to an 80G segment for instance. > Of course this would lead to potentially much more I/O which is why the > default would be the same behavior we see now. As it stands now, though, > there's no way to recover from an optimize/forceMerge except to re-index from > scratch. We routinely see 200G-300G Lucene indexes at this point "in the > wild" with 10s of shards replicated 3 or more times. And that doesn't even > include having these over HDFS. > Alternatives welcome! Something like the above seems minimally invasive. A > new merge policy is certainly an alternative. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org