If you're looking for something similar to some BPM (BPMN, BPEL...) engines 
in Clojure land, I *think* there is nothing similar here. I'm actually 
researching that area occasionally, and thinking wishfully about 
implementing one in Clojure someday.

When core.async appeared first, since it also comes from "process area" of 
IT (CSP, actors, process algebra...), I thought it would be sufficient for 
that case also, but unfortunately it seems it has some strong differences 
between BPM engines which are "session-based", meaning, each message that 
is received over channel marked as 'session creator' spawns new async 
process which is long, very long running (potentially years), and all 
subsequent messages that have correlation value for that process are routed 
to that session afterwards. 

Biggest similarity is that both approaches (BPM enginer and core.async) 
invert control of execution, meaning, you write easy-to-grasp sequential 
code which is executed asynchronously, but one would need option to stop 
the execution in some point of "go" block, persist it, and continue it 
later. In Java, Apache ODDE, which is BPEL engine, uses Pi-calculus engine 
underneath, that uses continuations queue and is able to persist the 
session on demand, and dehydrate it again when needed, even if that moment 
comes a year later..

In other words, we need something like durable, restartable, GO blocks, for 
each indivudual long-running session, and there can be hundreds of 
thousands of them active in a system simultaneously (think about hundred k 
of active purchase orders...).

-Vjeran

On Thursday, April 30, 2015 at 1:35:25 PM UTC+2, Tim Visher wrote:
>
> Hey All,
>
> Anyone have any tips on clojure 'workflow' libraries? 
> https://github.com/relaynetwork/impresario is very close, but lacks some 
> basic features like exception transitions, etc. 
>
> Basically, I'm looking for a library that allows me to create a workflow 
> that will happen asynchronously, recording it's progress in a db. I think i 
> could probably whip something together without _too_ much trouble using 
> core.async but this feels like something that's probably already been 
> written.
>
> Thanks in advance!
>
> --
>
> In Christ,
>
> Timmy V.
>
> http://blog.twonegatives.com/
> http://five.sentenc.es/ -- Spend less time on mail
>

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