> I'm not sure what point you are making with your scenario involving HTTP response codes.
My point was to identify how common the "happy path" scenario is and was in direct response to:
>> There is no value for logging "function entry/exit, with param values" when all collaborations succeed and the system operates as intended.
> Well, I agree completely, but those conditions are a tall order.
Regarding your question:
> What if the HTTP server crashes, and doesn't send a response at all?
Again, the HTTP status codes were used to illustrate the frequency of successful invocations. But to your point, if an HTTP server crashes then log entries for in-flight workflows would likely not be emitted. A similar possibility also holds for local file system logging as buffering exists (sometimes on multiple levels).
> I don't know from Writer Monads.
No worries. All it is is a formal definition of a type having specific capabilities called "laws" in the functional programming world.
> But if you only emitting log entries on some future failure or request, then that's potentially a lot of logging to keep somewhere. Where? Log aggregator? Local files? Memory?
What is meant by "future failure" is a failure potentially encountered during the evaluation of a single invocation. In the context of a HTTP server, this would be the handling of each submission to a specific HTTP endpoint and verb. This is often defined within an IO Monad[0], but does not have to be, and is out of scope for this discussion.
The answer to the rest of your questions is the deferred log entry definitions are held in memory for the duration of the single service invocation, with any log emissions produced transmitted to a network-accesible log aggregator via the logging component used.
> Let me be real clear about all calls and param values leading up to a failure.
The scenario you kindly shared is understandable, yet is one which has been unacceptable in teams I have worked with. Losing the "first error" is not an option in those environments.
My point was to identify how common the "happy path" scenario is and was in direct response to:
>> There is no value for logging "function entry/exit, with param values" when all collaborations succeed and the system operates as intended.
> Well, I agree completely, but those conditions are a tall order.
Regarding your question:
> What if the HTTP server crashes, and doesn't send a response at all?
Again, the HTTP status codes were used to illustrate the frequency of successful invocations. But to your point, if an HTTP server crashes then log entries for in-flight workflows would likely not be emitted. A similar possibility also holds for local file system logging as buffering exists (sometimes on multiple levels).
> I don't know from Writer Monads.
No worries. All it is is a formal definition of a type having specific capabilities called "laws" in the functional programming world.
> But if you only emitting log entries on some future failure or request, then that's potentially a lot of logging to keep somewhere. Where? Log aggregator? Local files? Memory?
What is meant by "future failure" is a failure potentially encountered during the evaluation of a single invocation. In the context of a HTTP server, this would be the handling of each submission to a specific HTTP endpoint and verb. This is often defined within an IO Monad[0], but does not have to be, and is out of scope for this discussion.
The answer to the rest of your questions is the deferred log entry definitions are held in memory for the duration of the single service invocation, with any log emissions produced transmitted to a network-accesible log aggregator via the logging component used.
> Let me be real clear about all calls and param values leading up to a failure.
The scenario you kindly shared is understandable, yet is one which has been unacceptable in teams I have worked with. Losing the "first error" is not an option in those environments.
0 - https://en.wikibooks.org/wiki/Haskell/Understanding_monads/I...