There are times where for no “obvious” reason your flow stops working and/or triggering very slow (we are talking about hours together to trigger the flow).This I’m particularly talking in the context of CDS Trigger (when a record created/updated/deleted). When I faced this problem last week in one of our lower environments, It turns out to be the problem is not in the Flow rather it is the Asynchronous services in CDS. One of our rouge workflows caused to trigger multiple child workflows causing a massive queue of waiting processes.
I know it is bit surprising but the truth is the Flow trigger is also based on the same Async pipe line of CDS where all your other async tasks (like workflows, async plugins and system jobs etc) are queued. If you are fast enough to refresh your system jobs or if you choke up your async pipe line, whenever CDS triggers a flow you will be able to see a system job as shown in below screenshot.
So, in a nutshell – Ensure your CDS Async pipe line is not filled up to avoid slow triggering of your flows.
Note: I’m not saying this is “the” reason why your flows are not triggering rather the intention is to say this could be one of the reasons and don’t forget to lookout 😊