[ https://issues.apache.org/jira/browse/SOLR-3221?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Erick Erickson reassigned SOLR-3221: ------------------------------------ Assignee: Erick Erickson > Make Shard handler threadpool configurable > ------------------------------------------ > > Key: SOLR-3221 > URL: https://issues.apache.org/jira/browse/SOLR-3221 > Project: Solr > Issue Type: Improvement > Affects Versions: 3.6 > Reporter: Greg Bowyer > Assignee: Erick Erickson > Labels: distributed, http, shard > Attachments: SOLR-3221-3x_branch.patch > > > From profiling of monitor contention, as well as observations of the > 95th and 99th response times for nodes that perform distributed search > (or ‟aggregator‟ nodes) it would appear that the HttpShardHandler code > currently does a suboptimal job of managing outgoing shard level > requests. > Presently the code contained within lucene 3.5's SearchHandler and > Lucene trunk / 3x's ShardHandlerFactory create arbitrary threads in > order to service distributed search requests. This is done presently to > limit the size of the threadpool such that it does not consume resources > in deployment configurations that do not use distributed search. > This unfortunately has two impacts on the response time if the node > coordinating the distribution is under high load. > The usage of the MaxConnectionsPerHost configuration option results in > aggressive activity on semaphores within HttpCommons, it has been > observed that the aggregator can have a response time far greater than > that of the searchers. The above monitor contention would appear to > suggest that in some cases its possible for liveness issues to occur and > for simple queries to be starved of resources simply due to a lack of > attention from the viewpoint of context switching. > With, as mentioned above the http commons connection being hotly > contended > The fair, queue based configuration eliminates this, at the cost of > throughput. > This patch aims to make the threadpool largely configurable allowing for > those using solr to choose the throughput vs latency balance they > desire. -- 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