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Martijn van Groningen commented on SOLR-3109: --------------------------------------------- No worries :-) I didn't want to move this work to anyone. Just wanted to say that the test needs to be updated. I put that comment b/c in the following three lines group.ngroups and group.truncate features are tested. These features *only* work properly if documents belonging to a group reside in the same shard. If documents belonging to a group do occur in more than one shard then the results are very likely incorrect. Tomorrow I will update the test case and get this patch committed. If you want to update the test case and have time for that that would be great! > 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 > Attachments: 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