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https://issues.apache.org/jira/browse/LUCENE-7440?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15484634#comment-15484634
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Mike Drob commented on LUCENE-7440:
-----------------------------------
bq. Regarding the 1.8B docs number... at least in my tests I saw the top-level
skip distance of ~268M w/ the default codec. Subtracting this from MAX_INT
gives around 1.8B, which is around the number I saw prior to the overflow. To
hit the bug, one also needs to be doing large skips toward the end of the index
as well, in order to use the top level(s) of the multi-level skip list. Having
a conjunction query of a highly unique term (or clause) in conjunction with a
common term has a good chance of triggering (example: +timestamp:39520928456494
+doctype:common)
Would this be faster to test if we configure a larger top-level skip distance?
i.e. set up a skip distance of ~1B and then we'd only need to get to ~1.1B docs
indexed (40% fewer docs, theoretically 40% faster?) or even set up a skip
distance of ~2B to only need to index very few documents?
Maybe this idea should be split into a separate issue to focus on improving the
test?
> Document skipping on large indexes is broken
> --------------------------------------------
>
> Key: LUCENE-7440
> URL: https://issues.apache.org/jira/browse/LUCENE-7440
> Project: Lucene - Core
> Issue Type: Bug
> Components: core/search
> Affects Versions: 2.2
> Reporter: Yonik Seeley
> Assignee: Yonik Seeley
> Priority: Critical
> Fix For: master (7.0), 6.3, 6.2.1
>
> Attachments: LUCENE-7440.patch, LUCENE-7440.patch
>
>
> Large skips on large indexes fail.
> Anything that uses skips (such as a boolean query, filtered queries, faceted
> queries, join queries, etc) can trigger this bug on a sufficiently large
> index.
> The bug is a numeric overflow in MultiLevelSkipList that has been present
> since inception (Lucene 2.2). It may not manifest until one has a single
> segment with more than ~1.8B documents, and a large skip is performed on that
> segment.
> Typical stack trace on Lucene7-dev:
> {code}
> java.lang.ArrayIndexOutOfBoundsException: 110
> at
> org.apache.lucene.codecs.MultiLevelSkipListReader$SkipBuffer.readByte(MultiLevelSkipListReader.java:297)
> at org.apache.lucene.store.DataInput.readVInt(DataInput.java:125)
> at
> org.apache.lucene.codecs.lucene50.Lucene50SkipReader.readSkipData(Lucene50SkipReader.java:180)
> at
> org.apache.lucene.codecs.MultiLevelSkipListReader.loadNextSkip(MultiLevelSkipListReader.java:163)
> at
> org.apache.lucene.codecs.MultiLevelSkipListReader.skipTo(MultiLevelSkipListReader.java:133)
> at
> org.apache.lucene.codecs.lucene50.Lucene50PostingsReader$BlockDocsEnum.advance(Lucene50PostingsReader.java:421)
> at YCS_skip7$1.testSkip(YCS_skip7.java:307)
> {code}
> Typical stack trace on Lucene4.10.3:
> {code}
> 6-08-31 18:57:17,460 ERROR org.apache.solr.servlet.SolrDispatchFilter:
> null:java.lang.ArrayIndexOutOfBoundsException: 75
> at
> org.apache.lucene.codecs.MultiLevelSkipListReader$SkipBuffer.readByte(MultiLevelSkipListReader.java:301)
> at org.apache.lucene.store.DataInput.readVInt(DataInput.java:122)
> at
> org.apache.lucene.codecs.lucene41.Lucene41SkipReader.readSkipData(Lucene41SkipReader.java:194)
> at
> org.apache.lucene.codecs.MultiLevelSkipListReader.loadNextSkip(MultiLevelSkipListReader.java:168)
> at
> org.apache.lucene.codecs.MultiLevelSkipListReader.skipTo(MultiLevelSkipListReader.java:138)
> at
> org.apache.lucene.codecs.lucene41.Lucene41PostingsReader$BlockDocsEnum.advance(Lucene41PostingsReader.java:506)
> at org.apache.lucene.search.TermScorer.advance(TermScorer.java:85)
> [...]
> at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:621)
> [...]
> at org.apache.solr.core.SolrCore.execute(SolrCore.java:2004)
> {code}
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