Info
When sharding a collection with a hashed shard key but including invalid options will output the following error:
mongos> sh.shardCollection("test.foo", {_id:"hashed"}, {pieinthesky:1})
{
"ok" : 0,
"errmsg" : "Hashed shard keys cannot be declared unique. It's possible to ensure uniqueness on the hashed field by declaring an additional (non-hashed) unique index on the field.",
"code" : 72,
"codeName" : "InvalidOptions",
"operationTime" : Timestamp(1541185291, 4),
"$clusterTime" : {
"clusterTime" : Timestamp(1541185291, 4),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
}
}
The problem is my invalid option, not the hashed shard key.
Top User Comments
daniel.hatcher commented on Mon, 5 Nov 2018 16:35:55 +0000:
Duplicates SERVER-37908 as the root issue is that the unique parameter (despite being optional) is required if options are specified.
Steps to Reproduce
Launch a sharded cluster
sh.enableSharding("test")
sh.shardCollection("test.foo", {_id:"hashed"}, {pieinthesky:1})
Error appears that is not indicative of the true problem
