[SOLR-8298] small preferLocalShards implementation refactor

• Type: Wish
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 5.4, 6.0
• Assignee: Christine Poerschke
• Reporter: Christine Poerschke
• Created: 16/Nov/15 19:32
• Updated: 14/Nov/16 14:30
• Resolved: 20/Nov/15 10:46

Description

Towards rebasing the SOLR-6730 patch after SOLR-6832 and other changes - proposed patch against trunk to follow.

existing calling chain:

• ResponseBuilder.addRequest(... ShardRequest sreq) does sreq.rb = this; so that later on HttpShardHandler.submit(ShardRequest sreq ...) can do sreq.rb.req.getOriginalParams().getBool for CommonParams.PREFER_LOCAL_SHARDS

proposed alternative calling chain:

• HttpShardHandler.prepDistributed(ResponseBuilder rb) sets rb.preferredHostAddress and SearchHandler calls ShardHandler.submit(ShardRequest sreq ... rb.preferredHostAddress)

structural changes:

• ShardRequest.rb member removed in favour of a new ResponseBuilder.preferredHostAddress member.
• String preferredHostAddress argument added to the abstract ShardHandler.submit method (and to two derived (test) classes' submit methods also).

• public void submit(ShardRequest sreq, String shard, ModifiableSolrParams params) { submit(sreq, shard, params, null); } 

  added to avoid having to change ShardHandler.submit callers which don't have a concept of preferring a local shard e.g. for PeerSync requests.

Issue Links

• is depended upon by: SOLR-6730 select?replicaAffinity=(node|host) and replicaAffinity.hostPriorities support
• relates to: SOLR-9758 refactor preferLocalShards implementation
• requires: SOLR-6832 Queries be served locally rather than being forwarded to another replica