clarification on FUNCTIONS_WORKER_PROCESS_COUNT and the concurrency level for each type of trigger

[dxynnez]

Hi team,

It's a bit unclear to me what does the FUNCTIONS_WORKER_PROCESS_COUNT do & in what case we would benefit by tweaking that number.

Does this work for .net isolated (on dedicated plan)? With the default value (1), would none of the functions run concurrently (by trigger type or by type & function name) ? If we increase the number, would that impact the event processing order (e.g., for session-enabled service bus queue, would multiple worker processes process msgs from the same session simultaneously and hence break the FIFO guarantee)?

Also, how does that impact the overall concurrency of the function app, since we already have concurrency control at the trigger level (e.g., durableTask:maxConcurrentActivityFunctions, durableTaskmaxConcurrentOrchestratorFunctions for durable function & serviceBus:maxConcurrentCalls, serviceBus:maxConcurrentSessions for service bus trigger function)?

Really appreciate if someone can shed some light here.

[dxynnez]

@fabiocav @brettsam is this something you can help to clarify? thanks so much!