[SOLR-14409] Existing violations allow bypassing policy rules when adding new replicas

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 8.5, 8.6, main (9.0)
• Fix Version/s: 8.6
• Component/s: AutoScaling
• Assignee: Noble Paul
• Reporter: Andrzej Bialecki
• Created: 16/Apr/20 09:34
• Updated: 15/Jul/20 15:09
• Resolved: 25/Jun/20 01:21

Description

Steps to reproduce:

• start with an empty cluster policy.
• create a collection with as many replicas as there are nodes.
• add one more replica to any node. Now this node has two replicas, all other nodes have one. 
• define the following cluster policy:

{ 'set-cluster-policy': [ {'replica': '<2', 'shard': '#ANY', 'node': '#ANY', 'strict': true} ] } 

This automatically creates a violation because of the existing layout.

• try adding one more replica. This should fail because no node satisfies the rules (there must be at most 1 replica per node). However, the command succeeds and adds replica to the node that already has 2 replicas, which clearly violates the policy and makes matters even worse.

 

Issue Links

• blocks: SOLR-12847 Cut over implementation of maxShardsPerNode to a collection policy
• links to: GitHub Pull Request #1598
• mentioned in: Page Loading...