Context

Currently, there's a bunch of logic that tries to pick which error to return after a failed retry. That logic frequently discards important error information and makes it difficult or impossible to troubleshoot problems without a bunch of additional event monitoring or logging enabled. It would be much more useful to collect all error information for all operation attempts and return them in one error, painting a much more complete picture of the history of a given operation in a single error value. To do that, we should use errutil.Join to join all errors that happen while attempting a given operation together.

Definition of done

• Join all operation errors together if the final retry does not succeed. Return the joined error.
• Join all errors that happen during transaction retries.
• Join all errors that happen during change stream retries.

Pitfalls

• We've never used errutil.Join before. It's possible there are unexpected behaviors created by that backward compatibility shim in Go 1.19 and older.
• We've never joined errors together. It's possible there will be unexpected error handling bugs introduced by returning joined errors.