[LUCENE-8005] Avoid Class.getSimpleName in UsageTrackingQueryCachingPolicy

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Scott Somerville
• Created: 23/Oct/17 17:50
• Updated: 28/Aug/22 15:20

Description

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:

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)