[SOLR-11832] Restore from backup creates old format collections

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 6.6.2, 7.2
• Component/s: Backup/Restore
• Assignee: Varun Thacker
• Reporter: Tim Owen
• Created: 08/Jan/18 20:17
• Updated: 21/Nov/19 03:41
• Resolved: 17/Jan/18 00:14

Description

Restoring a collection from a backup always creates the new collection using the old format state json (format 1), as a global clusterstate.json file at top level of ZK. All new collections should be defaulting to use the newer per-collection (format 2) in /collections/.../state.json

As we're running clusters with many collections, the old global state format isn't good for us, so as a workaround for now we're calling MIGRATESTATEFORMAT immediately after the RESTORE call.

This bug was mentioned in the comments of SOLR-5750 and also recently mentioned by [~varunthacker] in SOLR-11560

Code patch attached, but as per David Smiley's comment in the code, fixing this means at least 1 test class doesn't succeed anymore. From what I can tell, the BasicDistributedZk2Test fails because it's not using the official collection API to create a collection, it seems to be bypassing that and manually creating cores using the core admin api instead, which I think is not enough to ensure the correct ZK nodes are created. The test superclass has some methods to create a collection which do use the collection api so I could try fixing the tests (I'm just not that familiar with why those BasicDistributed*Test classes aren't using the collection api).

Issue Links

• is duplicated by: SOLR-11860 Change the default state format to 2