[SOLR-13142] Create Collection will put two replicas in same node

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Bug
• Affects Version/s: 7.6
• Component/s: SolrCloud
• Assignee: Unassigned
• Reporter: Lyle
• Created: 17/Jan/19 10:04
• Updated: 08/Jun/19 14:58
• Resolved: 22/Jan/19 09:34

Description

I have a solr cluster with two nodes, and both of them are alive.

Solr cluster: 

http://10.58.91.47:8082/search

http://10.58.91.83:8082/search

 

In solr7.5 when create a collection in two nodes cluster with shards=1 and replicationFactor=2, each node will have a replica.

However, in solr7.6, when use same request to create collection, two replicas will be put in same solr node.

example:

create collection request:

http://10.58.91.47:8082/search/admin/collections?action=CREATE&name=NewCollection&numShards=1&replicationFactor=2&collection.configName=conf&shards=shard1&maxShardsPerNode=1

response:

{
"responseHeader": {
"status": 0,
"QTime": 5392
},
"success": {
"10.58.91.47:8082_search": {
"responseHeader": {
"status": 0,
"QTime": 2584
},
"core": "NewCollection_shard1_replica_n1"
}
}
}

use clusterstatus request to query replica info:

request: http://10.58.91.83:8082/search/admin/collections?action=CLUSTERSTATUS&collection=NewCollection

response:

Tree
Chart
JSON Input
{
"responseHeader": {
"status": 0,
"QTime": 8
},
"cluster": {
"collections": {
"NewCollection": {
"pullReplicas": "0",
"replicationFactor": "2",
"shards": {
"shard1": {
"range": "80000000-7fffffff",
"state": "active",
"replicas": {
"core_node3": {
"core": "NewCollection_shard1_replica_n1",
"base_url": "http://10.58.91.47:8082/search",
"node_name": "10.58.91.47:8082_search",
"state": "active",
"type": "NRT"
},
"core_node4": {
"core": "NewCollection_shard1_replica_n2",
"base_url": "http://10.58.91.47:8082/search",
"node_name": "10.58.91.47:8082_search",
"state": "active",
"type": "NRT",
"leader": "true"
}
}
}
},
"router": {
"name": "compositeId"
},
"maxShardsPerNode": "1",
"autoAddReplicas": "false",
"nrtReplicas": "2",
"tlogReplicas": "0",
"znodeVersion": 4,
"configName": "conf"
}
},
"properties": {
"legacyCloud": "true"
},
"live_nodes": [
"10.58.91.47:8082_search",
"10.58.91.83:8082_search"
]
}
}

Is there any change for solr7.6 since I have not find any create collection API changes from document.

Could anyone please provide help?