[ https://issues.apache.org/jira/browse/SOLR-3109?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Martijn van Groningen resolved SOLR-3109. ----------------------------------------- Resolution: Fixed > group=true requests result in numerous redundant shard requests > --------------------------------------------------------------- > > Key: SOLR-3109 > URL: https://issues.apache.org/jira/browse/SOLR-3109 > Project: Solr > Issue Type: Bug > Components: search > Affects Versions: 3.5, 4.0 > Environment: 64-bit Linux, sharded environment > Reporter: Russell Black > Assignee: Martijn van Groningen > Priority: Critical > Labels: patch, performance > Fix For: 3.6, 4.0 > > Attachments: > SOLR-3109-Backport-of-grouping-performace-fix-to-3.x.patch, > SOLR-3109-lucene_solr_3_5.patch, SOLR-3109.patch, SOLR-3109.patch, > SOLR-3109.patch > > > During the second phase of a group query, the collator sends a query to each > of the shards. The purpose of this query is for shards to respond with the > doc ids that match the set of group ids returned from the first phase. The > problem is that it sends this second query to each shard multiple times. > Specifically, in an environment with n shards, each shard will be hit with an > identical query n times during the second phase of query processing, > resulting in O(_n_ ^2^) performance where _n_ is the number of shards. > I have traced this bug down to a single line in > {{TopGroupsShardRequestFactory.java}}, and I am attaching a patch. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org