Issue with parallel flows when activity Chaining is applied

RE: Issue with parallel flows when activity Chaining is applied

Priyanka! — Tue, 03 Jun 2025 04:17:45 GMT

Thank you all for replying to this thread, as mentioned by Mike Schmitt and David Jimenez chaining need deterministic path to execute on priority. My issue got resolve applying chaining for one path and removing from other. This way chaining is not breaking anywhere and parallel execution is also happening as expected.

RE: Issue with parallel flows when activity Chaining is applied

Harsha Sharma — Thu, 29 May 2025 07:46:41 GMT

As others suggested here, its better to merge both parallel flows so they execute sequentially. Also try to keep the chaining till the node on which the parent process depends or expects output from, because activity chained nodes themselves can slow the performance/execution of process.

RE: Issue with parallel flows when activity Chaining is applied

David Jimenez — Wed, 28 May 2025 20:21:38 GMT

No , it means that you won't be able to predict what it will happen.

And yes , you must avoid the use of an AND gateway in this case, try to implement it in a sequential flow

RE: Issue with parallel flows when activity Chaining is applied

Mike Schmitt — Wed, 28 May 2025 18:55:45 GMT

I'm unclear what parallel flows buys you here when both flows are unattended. You may as well put all the items in sequence (especially since when the two flows are running in parallel, even if chaining worked there'd be no way to assure what order the nodes execute in, meaning you should be able to make the two paths sequential anyway).

RE: Issue with parallel flows when activity Chaining is applied

Priyanka! — Wed, 28 May 2025 18:20:16 GMT

So does this mean system wait to complete any one path and then goes to another path?

If so then AND gateway is not serving the purpose here isn't it?

RE: Issue with parallel flows when activity Chaining is applied

Priyanka! — Wed, 28 May 2025 18:17:29 GMT

Hi Mike,
This just example process I shared, in my scenario I need to call multiple integration to form the final response of web API. Hence I tried to call those integration in parallel flows with chaining.

RE: Issue with parallel flows when activity Chaining is applied

Priyanka! — Wed, 28 May 2025 18:15:31 GMT

Hi Stefan,

Thanks for responding, this is 24.4.
I have observed this on start process nodes only.

RE: Issue with parallel flows when activity Chaining is applied

David Jimenez — Wed, 28 May 2025 17:43:51 GMT

Activity chaining requires a deterministic path. In a parallel flow, multiple paths execute simultaneously, and the system cannot predict which one will complete first, making chaining unpredictable or impossible.

RE: Issue with parallel flows when activity Chaining is applied

Mike Schmitt — Wed, 28 May 2025 17:10:05 GMT

Logically, chaining can only really apply across one branch of an AND gateway.

RE: Issue with parallel flows when activity Chaining is applied

Stefan Helzle — Wed, 28 May 2025 13:53:05 GMT

Which Appian version is this? Since 24.4 activity chaining has no impact on the behaviour when using a!startProcess.