Multiple parallel tasks, number of tasks is not known in advance

BPMN & Modeling Discussion & Questions
1

I am working on a tool which will process big video files, splitting them into parts, and running processing in parallel on several workers. I am going to split video file into fixed length chunks.

The problem is that I do not know the length of incoming video files - they can be short, or they can be really long. So I do not know in advance number of chunks to process.

I am a newbie in BPMN. How can I draw a BPMN, that would spawn parallel blocks, while the actual number of blocks is determined in runtime?

2

Can you calculate amount of workers needed before you start the first one?

If so, you can use multi-instance with calculated value in loop cardinality.

You can use the multi-instance in subprocess or task.

See Task Markers | docs.camunda.org

1 Like
3

Thank you for pointing to multi-instance feature. Looks like this is what I need.

Can you calculate amount of workers needed before you start the first one?

I cannot know about number of workers needed before job is started, but I can calculate it in a preparation/analysis block I can add. Is this a valid approach in conjunction with multi-instance block?

4

Hi @grafalex,

yes, that’s the way to go.