From robert.guo:

Andreas and I wanted to get your opinion on a potentially confusing error message in the encryptor code that's likely going to be very common for users. It's this line here: https://github.com/mongodb/mongo/blob/master/src/third_party/wiredtiger/src/conn/conn_api.c#L391

The error says "WiredTiger (22) [1437079556:927507][74761:0x7fff73142000], connection: unknown encryptor 'aes': Invalid argument" and is triggered when the starts mongod with encryption first, then restart it without.

This might be confusing for users who most likely wouldn't be aware of encryption at all. I wanted to discuss with you on how we'd like to handle this situation. One solution might be to add a check to see if an encryptor is provided at all. If not, we can give a different error message.

andreas.nilsson@10gen.com says:

Additionally we're having some problems with detecting if a database have been opened without encryption before. I think we need to abort starting with encryption enabled since it puts the data files in some undefined state.

It seems like WT is happy just starting up with encryption callbacks even if it wasn't before right?