[SOLR-12847] Cut over implementation of maxShardsPerNode to a collection policy

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Fix Version/s: master (9.0)
• Component/s: AutoScaling, SolrCloud
• Assignee: Andrzej Bialecki
• Reporter: Shalin Shekhar Mangar
• Created: 09/Oct/18 08:12
• Updated: 13/Aug/20 15:37
• Resolved: 27/Jul/20 11:01

Description

We've back and forth over handling maxShardsPerNode with autoscaling policies (see SOLR-11005 for history). Now that we've reimplemented support for creating collections with maxShardsPerNode when autoscaling policy is enabled, we should re-look at how it is implemented.

I propose that we fold maxShardsPerNode (if specified) to a collection level policy that overrides the corresponding default in cluster policy (see SOLR-12845). We'll need to ensure that if maxShardsPerNode is specified then the user sees neither violations nor corresponding suggestions because of the default cluster policy.

Issue Links

• is blocked by: SOLR-14409 Existing violations allow bypassing policy rules when adding new replicas
• relates to: SOLR-13248 Autoscaling based replica placement is broken out of the box
• links to: GitHub Pull Request #1417
• links to: GitHub Pull Request #1637