[SOLR-5295] The createshard collection API creates maxShardsPerNode number of replicas if replicationFactor is not specified

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.5
• Fix Version/s: 4.5.1, 4.6, 6.0
• Component/s: SolrCloud
• Assignee: Shalin Shekhar Mangar
• Reporter: Shalin Shekhar Mangar
• Created: 02/Oct/13 05:09
• Updated: 09/May/16 18:53
• Resolved: 02/Oct/13 11:32

Description

As reported by Brett Hoerner on solr-user:
http://www.mail-archive.com/[e-mail]/msg89545.html

It seems that changes in 4.5 collection configuration now require users to
set a maxShardsPerNode (or it defaults to 1).

Maybe this was the case before, but with the new CREATESHARD API it seems a
very restrictive. I've just created a very simple test collection on 3
machines where I set maxShardsPerNode at collection creation time to 1, and
I made 3 shards. Everything is good.

Now I want a 4th shard, it seems impossible to create because the cluster
"knows" I should only have 1 shard per node. Yet my problem doesn't require
more hardware, I just my new shard to exist on one of the existing servers.

So I try again – I create a collection with 3 shards and set
maxShardsPerNode to 1000 (just as a silly test). Everything is good.

Now I add shard4 and it immediately tries to add 1000 replicas of shard4...