[SOLR-6571] Need a znode watcher support class

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: SolrCloud
• Assignee: Unassigned
• Reporter: Timothy Potter
• Created: 29/Sep/14 16:03
• Updated: 29/Sep/14 20:35
• Resolved: 29/Sep/14 17:25

Description

When implementing SOLR-6249, noble.paul points out that ZkIndexSchemaReader doesn't watch the managed schema znode correctly and should use a strategy similar to what ZkStateReader does so that watchers persist across zk client connection failures:

The correct example is the constructor of ZkStateReader
zkClient = new SolrZkClient(zkServerAddress, zkClientTimeout, zkClientConnectTimeout,
// on reconnect, reload cloud info
new OnReconnect()

{ //implement stuff here }

});
this ensures that the watchers are persisted across reconnect.

We need a watch support class to help developers implement watchers correctly instead of having some code do it correctly and other code not.