With a sharded setup, enable sharding on a collection:

> db.runCommand( { shardcollection : "test.testshard", key :

{ name : 1, age: 1 }

} )
> use test
> db.testshard.insert(

{ age: 1 }

)

• • Actual behavior:

... one second later ...

"tried to insert object with no valid shard key for

{ name: 1.0, age: 1.0 }

:

{ _id: ObjectId('4ff1ecd2118f035ab2938dad'), age: 1.0 }

"

• • Expected behavior:

The error message should respond immediately.

These delays "stack up"; e.g. for each invalid document inserted, the delayed response increases by one second. So, with a nodejs program, 6 parallel inserts (followed by getLastError) means waiting for 6 seconds to get the error response.