[
https://issues.apache.org/jira/browse/LUCENE-8005?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16215797#comment-16215797
]
Robert Muir commented on LUCENE-8005:
-------------------------------------
{quote}
So a sizable improvement but not as fast as an instanceof check.
{quote}
But this is not the bottleneck for lucene's processing so we can't make
decisions that way. Otherwise we optimize the wrong stuff. i wish it was the
bottleneck, that 10 million queries could run in 20ms versus 900ms. But a ~ 100
ns cost to check if a query is cached seems reasonable to me. And the current
speed of ~ 1 microsecond per query seems also just fine.
I am more concerned that we don't introduce bad apis and complex abstractions.
In this case I'm sorry, i dont see a performance justification for that.
> Avoid Class.getSimpleName 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, 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: [email protected]
For additional commands, e-mail: [email protected]
