On 05/01/2017 13:30, Morten Bøgeskov wrote:
Hi. We've got a SolrCloud which is sharded and has a replication factor of 2. The 2 replicas of a shard may look like this: Num Docs: 5401023 Max Doc: 6388614 Deleted Docs: 987591 Num Docs: 5401023 Max Doc: 5948122 Deleted Docs: 547099 We've seen >10% difference in Max Doc at times with same Num Docs. Our use case is few documents that are search and many small that are filtered against (often updated multiple times a day), so the difference in deleted docs aren't surprising. This results in a different score for a document depending on which replica it comes from. As I see it: it has to do with the different maxDoc value when calculating idf. This in turn alters a specific document's position in the search result over reloads. This is quite confusing (duplicates in pagination). What is the trick to get homogeneous score from different replicas. We've tried using ExactStatsCache & ExactSharedStatsCache, but that didn't seem to make any difference. Any hints to this will be greatly appreciated.
This was one of things we looked at during our recent Lucene London Hackday (see item 3) https://github.com/flaxsearch/london-hackday-2016
I'm not sure there is a way to get a homogenous score - this patch tries to keep you connected to the same replica during a session so you don't see results jumping over pagination.
Cheers Charlie -- Charlie Hull Flax - Open Source Enterprise Search tel/fax: +44 (0)8700 118334 mobile: +44 (0)7767 825828 web: www.flax.co.uk
