In short, when running a distributed search every shard runs the query separately. Each shard's collector returns the topN (rows param) internal docId's of the matching documents.
These topN docId's are converted to their uniqueKey in the BinaryResponseWriter and sent to the frontend core (the one the received the query). This conversion is implemented by a StoredFieldVisitor, meaning the uniqueKeys are read from their stored field and not from their docValues. As in our use-case we have a high row param, these conversions became a performance bottleneck. We implemented a user-cache that stores the shard's uniqueKey docValues, which is a [docId, uniqueKey] mapping. This eliminates the need of accessing the stored field for these frequent conversions. You can have a look at the patch. Feel free commenting https://issues.apache.org/jira/browse/SOLR-5478 Best, Manuel On Thu, Jan 9, 2014 at 7:33 PM, ku3ia <dem...@gmail.com> wrote: > Today I setup a simple SolrCloud with tow shards. Seems the same. When I'm > debugging a distributed search I can't catch a break-point at lucene codec > file, but when I'm using faceted search everything looks fine - debugger > stops. > > Can anyone help me with my question? Thanks. > > > > -- > View this message in context: > http://lucene.472066.n3.nabble.com/Solr-4-6-0-DocValues-distributed-search-tp4110289p4110511.html > Sent from the Solr - User mailing list archive at Nabble.com. >
