Hello all, I was looking into the source code for org.apache.lucene.facet.FacetsConfig as it's being highlighted as an hotspot of allocations during a performance analysis session.
Our code was allocating a new instance of FacetsConfig for each Document being built; there are several maps being allocated by such an instance, both as instance fields and on the hot path of method "#build(Document doc)". My understanding from reading the code is that it's designed to be multi-threaded, probably to reuse one instance for a single index? That would resolve my issue with allocations at instance level, and probably also the maps being allocated within the build method as the JVM seems to be smart enough to skip those; at least that's my impression with a quick experiment. However reusing this single instance across all threads would become a contention point as all getters to read the field configurations are synchronized. Since the maps being read are actually safe ConcurrentMap instances, I see no reason for the "synchronized", so really it just boils down to a trivial patch to remove those on the reader methods. May I open a JIRA and propose a patch for that? As a second step, I'd also like to see if the build method could be short-circuited for a quick return: in case there are no faceted fields would be great to just return with the input document right away. Thanks, Sanne --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
