[SOLR-9758] refactor preferLocalShards implementation

• Type: Task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 6.4, 7.0
• Assignee: Christine Poerschke
• Reporter: Christine Poerschke
• Created: 14/Nov/16 14:28
• Updated: 08/Jun/19 15:31
• Resolved: 22/Dec/16 10:36

Description

This ticket proposes to refactor the existing preferLocalShards implementation (from SOLR-6832 and SOLR-8298) based upon the recent (in SOLR-8332) ReplicaListTransformer addition.

The intention of the refactor is to encapsulate the local shard url selection logic within the HttpShardHandlerFactory.getReplicaListTransformer method (it is currently spread across the public HttpShardHandler.prepDistributed and the private HttpShardHandler.getURLs method) and to thus remove the ResponseBuilder.preferredHostAddress field.

Issue Links

• is related to: SOLR-6832 Queries be served locally rather than being forwarded to another replica
• is related to: SOLR-8332 factor HttpShardHandler[Factory]'s url shuffling out into a ReplicaListTransformer class
• is related to: SOLR-8298 small preferLocalShards implementation refactor