The ODMs need to either:

• never use the upsert=True when updating documents, or
• track the shard key for a collection and automatically add the shard key to updates with upsert=True

Original Server ticket description :

Currently, replacement style updates target using the update rather than the query. We should change this to target using the query instead.

As of today, we do not allow users to change the shard key for a document. If shard 1 owns the chunk with range (shardKey : min, shardKey : 500) and shard 2 owns the chunk with range (shardKey : 500, shardKey : max) and a user sends

db.coll.update({shardKey : 100}, {shardKey : 800})

the update will be sent to shard 2 and we return

{ok: 1.0, nMatched : 0)

We should actually get an ImmutableField error.

Once we allow a user to update the shard key for a document (PM-1163), the above update should cause the document to change shards. However, since the update would be sent to shard 2, shard 1 will never actually see this update and the update will not be applied.