[SOLR-11807] maxShardsPerNode=-1 needs special handling while restoring collections

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 7.5, 8.0
• Component/s: Backup/Restore
• Assignee: Varun Thacker
• Reporter: Varun Thacker
• Created: 31/Dec/17 02:22
• Updated: 21/Nov/19 00:41
• Resolved: 21/Jun/18 09:04

Description

When you start Solr 6.6. and run the cloud example here's the log excerpt :

Connecting to ZooKeeper at localhost:9983 ...

INFO  - 2018-06-20 13:44:47.491; org.apache.solr.client.solrj.impl.ZkClientClusterStateProvider; Cluster at localhost:9983 ready
...

Creating new collection 'gettingstarted' using command:

http://localhost:8983/solr/admin/collections?action=CREATE&name=gettingstarted&numShards=2&replicationFactor=2&maxShardsPerNode=2&collection.configName=gettingstarted

maxShardsPerNode get's set to 2 . 

 

Compare this to Solr 7.3 

INFO  - 2018-06-20 13:55:33.823; org.apache.solr.client.solrj.impl.ZkClientClusterStateProvider; Cluster at localhost:9983 ready

Created collection 'gettingstarted' with 2 shard(s), 2 replica(s) with config-set 'gettingstarted'

So something changed and now we no longer set maxShardsPerNode and it defaults to -1 . 

 

-1 has special handing while creating a collection ( it means max int ) . This special handling is not there while restoring a collection and hence this fails

We should not set maxShardsPerNode to -1 in the first place

Steps to reproduce:

1. ./bin/solr start -e cloud -noprompt : This creates a 2 node cluster and a gettingstarted collection which 2X2
2. Add 4 docs (id=1,2,3,4) with commit=true and openSearcher=true (default)
3. Call backup: http://localhost:8983/solr/admin/collections?action=BACKUP&name=gettingstarted_backup&collection=gettingstarted&location=/Users/varunthacker/solr-7.1.0
4. Call restore:
http://localhost:8983/solr/admin/collections?action=restore&name=gettingstarted_backup&collection=restore_gettingstarted&location=/Users/varunthacker/solr-7.1.0

Issue Links

• is related to: SOLR-11239 Deprecate maxSHardsPerNode when autoscaling policies are used
• is related to: SOLR-11823 Incorrect number of replica calculation when using Restore Collection API