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Greg Miller commented on LUCENE-10068: -------------------------------------- [~gworah] would you mind re-running benchmarks now that [~mikemccand] has added more faceting tasks in {{luceneutil}}? (see: https://github.com/mikemccand/luceneutil/issues/137) > Switch to a "double barrel" HPPC cache for the taxonomy LRU cache > ----------------------------------------------------------------- > > Key: LUCENE-10068 > URL: https://issues.apache.org/jira/browse/LUCENE-10068 > Project: Lucene - Core > Issue Type: Improvement > Components: modules/facet > Affects Versions: 8.8.1 > Reporter: Gautam Worah > Priority: Minor > Attachments: disable_taxo_category_cache_benchmark > > > While working on an unrelated getBulkPath API > [PR|https://github.com/apache/lucene/pull/179], [~mikemccand] and I came > across a nice optimization that could be made to the taxonomy cache. > The taxonomy cache today caches frequently used ordinals and their > corresponding FacetLabels. It uses the existing LRUHashMap (backed by a > LinkedList) class for its implementation. > This implementation performs sub optimally when it has a large number of > threads accessing it, and consumes a large amount of RAM. > [~mikemccand] suggested the idea of a two array backed HPPC int->FacetLabel > cache. The basic idea behind the cache being: > # We use two hashmaps primary and secondary. > # In case of a cache miss in the primary and a cache hit in the secondary, > we add the key to the primary map as well. > # In case of a cache miss in both the maps, we add it to the primary map. > # When we reach (make this check each time we insert?) a large number of > elements in say the primary cache, (say larger than the existing > {color:#871094}DEFAULT_CACHE_VALUE{color}=4000), we dump the secondary map > and copy all the values of the primary map into it. > The idea was originally explained in > [this|https://github.com/apache/lucene/pull/179#discussion_r692907559] > comment. > > -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org