Comment by yegle
1 month ago
As someone who's daily job is to move protobuf messages around, I don't think protobuf is a good example to support your point :-)
AFAIKT, binary format of a protobuf message is strictly to provide a strong forward/backward compatibility guarantee. If it's not for that, the text proto format and even the jaon format are both versatile, and commonly used as configuration language (i.e. when humans need to interact with the file).
You can also provide this with JSON and API versioning. Also with JSON, you can add new fields to requests and responses, it's only deleting fields which breaks compatibility.
There's no simple replacement for what Protobuf does. Forwards and backwards compatibility is well-specified across clients in all languages. I can write a v2 message with new fields and pass it to a service written in a different language based on the v1 message schema. That service can modify the message using only its v1 schema, but when it re-emits the modified message, its original v2 fields will be intact.
You may think, "I don't need that," but once you've got more than a couple microservices, you'd be surprised how many headaches this type of compatibility issue can cause. You may think, "I can do that with json," but can you do exactly the same version of it across 4 or 5 different languages while maintaining a single source of truth for each message type's schema? At that point, you're just rebuilding Protobuf.
Afaik the only other tool that does what Protobuf does is Avro, though I haven't used it. I have tried to use json-schema for this, but that's not what it was made for. The schema evolution story is worse, and the codegen isn't as good.