I upgraded my cluster to Elasticsearch 6 and while it is working, none of the redundant shards are being allocated 
When I use the explain API I get this:
curl -XGET 'localhost:9200/_cluster/allocation/explain?pretty'
{
"index" : "px-ext-access-2016.09.01",
"shard" : 4,
"primary" : false,
"current_state" : "unassigned",
"unassigned_info" : {
"reason" : "REPLICA_ADDED",
"at" : "2017-11-17T07:02:48.361Z",
"last_allocation_status" : "no_attempt"
},
"can_allocate" : "no",
"allocate_explanation" : "cannot allocate because allocation is not permitted to any of the nodes",
"node_allocation_decisions" : [
{
"node_id" : "8SjCHI-OQn-mBAl0OBLx6Q",
"node_name" : "bos1-es2",
"transport_address" : "192.168.8.151:9300",
"node_attributes" : {
"ml.max_open_jobs" : "10",
"ml.enabled" : "true"
},
"node_decision" : "no",
"deciders" : [
{
"decider" : "enable",
"decision" : "NO",
"explanation" : "no allocations are allowed due to {}"
}
]
},
{
"node_id" : "JR9qqMjEQF6c22eGZqIAcw",
"node_name" : "bos1-es3",
"transport_address" : "192.168.8.152:9300",
"node_attributes" : {
"ml.max_open_jobs" : "10",
"ml.enabled" : "true"
},
"node_decision" : "no",
"deciders" : [
{
"decider" : "enable",
"decision" : "NO",
"explanation" : "no allocations are allowed due to {}"
},
{
"decider" : "same_shard",
"decision" : "NO",
"explanation" : "the shard cannot be allocated to the same node on which a copy of the shard already exists [[px-ext-access-2016.09.01][4], node[JR9qqMjEQF6c22eGZqIAcw], [P], s[STARTED], a[id=IO9Hx2mpScqfigUPaX7mkQ]]"
}
]
},
{
"node_id" : "tBZdi1W_TRa16getb8eNlA",
"node_name" : "bos1-es1",
"transport_address" : "192.168.8.150:9300",
"node_attributes" : {
"ml.max_open_jobs" : "10",
"ml.enabled" : "true"
},
"node_decision" : "no",
"deciders" : [
{
"decider" : "enable",
"decision" : "NO",
"explanation" : "no allocations are allowed due to {}"
}
]
}
]
}
Help what do I do! I checked and all the cluster members are running 6.0.0 so I don't think there is a version mismatch issue.
