Cannot use commands write mode error, Degrading to compatibility mode

Question

I just play with mongo shell and came across with Cannot use commands write mode, degrading to compatibility mode.

I connected to remote mongo server (mong

Answer 1

You are using a shell that's newer than the server it's communicating with.

You can check the server version from the shell via db.version() - to check shell version you use version()

Starting with 2.6 the mongod server started using new write commands which are different than the previously use insert/update/remove op code (this is all described in the MongoDB Wire Protocol).

This is a harmless "informational" warning. It's a good idea to use the same version shell as the server to avoid wondering about such things though.