[SOLR-7130] Make stale state notification work without failing the requests

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 5.1, 6.0
• Component/s: clients - java, SolrCloud, SolrJ
• Assignee: Noble Paul
• Reporter: Shalin Shekhar Mangar
• Created: 19/Feb/15 19:46
• Updated: 09/May/16 18:47
• Resolved: 26/Feb/15 13:27

Description

I wasn't sure whether to label this a bug or an improvement.

For collections with stateFormat=2, we now fail requests (because of stale state) which we didn't previously. The client having stale cached cluster state is not a sufficient reason to fail and retry the entire request because in most of such cases, the node receiving the request is still perfectly capable of returning a valid response (either from local replicas or remote ones).

We should find a better way to notify clients that they have stale state. Perhaps we can modify the response and add a "routing" section instead of outright exception.

Issue Links

• incorporates: SOLR-7129 CloudSolrClient can put extra load on ZooKeeper for collections with stateFormat=2
• is duplicated by: SOLR-7129 CloudSolrClient can put extra load on ZooKeeper for collections with stateFormat=2