Immutable thrift service interface

About Immutable Infrastructure

• Automate the setup and deployment for every part and every layer of your infrastructure.
• Never change any part of your system once it is deployed. If you need to change it, deploy a new system

About Thrift service

Remote procedure call refers to the technique of making a local call and having it execute on a remote service somewhere. Thrift make it easy to define and create a remote procedure call service. Checkout Thrift: the missing guide to explore basic usage.

Question: But when we meet the problem of API amending?

There are some backward compatible changes that will not make inpact on existing callers:

• Adding new methods or structs
• Adding a non-required field to a struct
• Changing a method return type from void to anything else
• Removing an exception from a method signature
• Adding an argument to a method with or without a default value

and some are imcompatible changes:

• Removing a field from a struct
• Renaming a struct
• Removing an argument from a method
• Changing the order of arguments in a method
• Changing the namespace
• Removing or renaming a method
• Changing the type of an argument in a method
• Changing the declared type of a return value, or changing it to void
• Adding an exception to a method (with a non-void return type)

If we want to make our thrift service always backward compatible, make it immutable!

Immutable interface

Don’t doing imcompatible changes, instead of adding a new method, keeping legacy method existing but deprecated until no callers.