Loop asynchronous problem

[StephanHaarmann]

Oh, sorry – I had not understood the message flow in your processes fully.
So: P1 invokes P3 which invokes P2 which then should receive a message from P1, right?

The message flow cannot guarantee that P2 is ready. Either P2 or P3 have to communicate to P1 that P2 has been started. Only then can the message be sent.

When we work in a distributed setting (and I consider multiple communicating processes as a distributed system), messages are the primary (if not the only) means for synchronization. Camunda 7 does not buffer messages, so we have to use message to tell the partner that we are ready or take care of buffering messages.

The latter has been discussed several times in the forum, e.g.:

Message Buffer Plugin

Hey I have been working on a message buffer plugin. Wanted to check with the community while “tightening the screws” to see if functions are covered: The plugin provides a message buffer for correlating messages. Most common use case is when you have race conditions where the message sender sends the message before camunda is ready to receive the message. If the message message correlation returns no results or not the expected number of results, then will try again with the following featu…

Buffering of received messages

Hello, camunda BPM has a somewhat unpleasant property that, if a process has an intermediate receive message activity, the process must have arrived at this activity in order to be able to receive that message. If a sender wants to send the message before the process has arrived at the receive activity, it (the sender) will fail. This is a pity because, quite often, we can not control when the external events occur and when the messages are sent to processes. As a result, we have to specially …