[Error Codes] Updated MessageTooLarge

[jamdavi]

No description provided.

[drwill-ms]

We recently learned that we can get 2 different errors depending on how large the message is. Meaning, if > 1MB, we get a different one, and if too large but < 1MB we get this one.

It might be worth noting that. @abhipsaMisra has more info, IIRC.

[abhipsaMisra]

You're right, we did have this behavior which has now been fixed in master: #2053. We'll now see MessageTooLargeException for all message sizes over 256kb limit then sent via AMQP/HTTP.
MQTT , however, will perform a client-level validation and throw an InvalidOperationException instead. This would be worth calling out:

azure-iot-sdk-csharp/iothub/device/src/Transport/Mqtt/MqttIotHubAdapter.cs

Line 1175 in d46e0f0

throw new InvalidOperationException($"Message size ({streamLength} bytes) is too big to process. Maximum allowed payload size is {MaxPayloadSize}");

[jamdavi]

So, just to keep things clean we should probably not mention this exception because they are only related by the concept of message size. A customer who is getting the MessageTooLargeException wouldn't need to know about the other limit.

We probably should have repurposed this exception for the >1MB issue.