lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Robert Muir (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (LUCENE-8005) Avoid Reflection in UsageTrackingQueryCachingPolicy
Date Mon, 23 Oct 2017 18:03:00 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-8005?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16215539#comment-16215539
] 

Robert Muir commented on LUCENE-8005:
-------------------------------------

Are you sure there is a real performance problem? I don't believe that accessing a class's
getSimpleName is expensive.

Such "sampling" profiling techniques are fundamentally broken with java: http://psy-lob-saw.blogspot.com/2016/02/why-most-sampling-java-profilers-are.html


> Avoid Reflection in UsageTrackingQueryCachingPolicy
> ---------------------------------------------------
>
>                 Key: LUCENE-8005
>                 URL: https://issues.apache.org/jira/browse/LUCENE-8005
>             Project: Lucene - Core
>          Issue Type: Improvement
>            Reporter: Scott Somerville
>         Attachments: LUCENE-8005.patch
>
>
> By profiling an Elasticsearch cluster, I found the private method UsageTrackingQueryCachingPolicy.isPointQuery
to be quite expensive due to the clazz.getSimpleName() call.
> Here is an excerpt from hot_threads:
> {noformat}
> java.lang.Class.getEnclosingMethod0(Native Method)
>        java.lang.Class.getEnclosingMethodInfo(Class.java:1072)
>        java.lang.Class.getEnclosingClass(Class.java:1272)
>        java.lang.Class.getSimpleBinaryName(Class.java:1443)
>        java.lang.Class.getSimpleName(Class.java:1309)
>        org.apache.lucene.search.UsageTrackingQueryCachingPolicy.isPointQuery(UsageTrackingQueryCachingPolicy.java:39)
>        org.apache.lucene.search.UsageTrackingQueryCachingPolicy.isCostly(UsageTrackingQueryCachingPolicy.java:54)
>        org.apache.lucene.search.UsageTrackingQueryCachingPolicy.minFrequencyToCache(UsageTrackingQueryCachingPolicy.java:121)
>        org.apache.lucene.search.UsageTrackingQueryCachingPolicy.shouldCache(UsageTrackingQueryCachingPolicy.java:179)
>        org.elasticsearch.index.shard.ElasticsearchQueryCachingPolicy.shouldCache(ElasticsearchQueryCachingPolicy.java:53)
>        org.apache.lucene.search.LRUQueryCache$CachingWrapperWeight.bulkScorer(LRUQueryCache.java:806)
>        org.elasticsearch.indices.IndicesQueryCache$CachingWeightWrapper.bulkScorer(IndicesQueryCache.java:168)
>        org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:665)
>        org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:472)
>        org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:388)
>        org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:108)
> {noformat}



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org


Mime
View raw message