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Microsoft Bond schema evolution best practices

Does Microsoft Bond have some best practices on how schemas evolve over time? I want to make certain we follow best practices such that we have 2 way compatibility (i.e. allowing our Bond types to evolve older versions to the current version, as well as backward compatibility allowing conversion from a newer version back to an older version). I don't see this addressed specifically in the documentation (e.g. https://microsoft.github.io/bond/manual/bond_cs.html nor https://microsoft.github.io/bond/manual/compiler.html#idl-syntax ), though other serialization frameworks such as Avro have this explicitly detailed in their documentation.

For what it's worth, we are writing in .NET (C#/F#) and intend to use the CompactBinaryWriter and CompactBinaryReader formats initially.

For example, I imagine some guidance along these lines:

  1. names of fields can change over time since the field ordinals are used for field resolution, not the names directly (except in SimpleJSON). I believe this true, is it?
  2. adding a new "required" field requires you give the field a default value
  3. removing a field in a newer version is okay, provided older versions had a default value assigned
  4. what about changing the type of a field? For example, can a field change from an string field in version 1 to a int64 in version 2? Can it change from a string to a custom union (custom type with optional fields)?
  5. any other recommendations?

Thank you!

would also be interested if there is any active forum community for this type of Microsoft Bond question, i wasn't able to find one...

Solution

  • The Bond schema evolution rules and best practices can now be found here: https://microsoft.github.io/bond/manual/bond_cpp.html#schema-evolution https://microsoft.github.io/bond/manual/bond_cs.html#schema-evolution