gRPC backward compatability
Keeping backward compatability is always important. gRPC is new grounds for many, so it’s easy to get lost in what’s considered “breaking changes” or not.
Non-breaking changes
Adding a new service
Adding a new method to a service
Adding a value to an enum
Adding a field to the end of a message
The Go gRPC library does not support added fields to response or request messages when they are added at the beginning or middle of the message, as it uses the index of the field to map the values.[verification needed]
Breaking changes
Kind of any other changes that are not specified in the “Non-breaking changes” section above.
Removing a service
Changing a service (ex: name)
Removing methods from a service
Changing methods from a service (ex: name, signature)
Removing a field in a message
Changing the type of a field in a message
Changing a field number, for example by reordering them.
How to handle breaking changes
Up the protocol version.
This may happen frequently, and may be another good use case for applying some git-flow with release-branches.
