QMC Tasks - Multiple tasks calling the same qvds

[kdmarkee]

I think the answer is yes, but am hoping someone can confirm this.  Will the QlikView 12 QMC support two separate tasks calling the same set of qvds at the same time?  For example, if I have a task 2 where app2.qvw loads abc.qvd and xyz.qvd and task 3 where app3.qvw loads the same two qvds at the same time, will that cause problems?  Additionally, both tasks 2 and 3 will automatically kick off via a trigger based on the completion of completely separate task, ie, let's call it task 1.  Thanks in advance for your help.

[marcus_sommer · Accepted solution]

I suggest to rather avoid such a scenario because there could occur file-locks especially if these qvd's aren't just to read else to write them per store-statement. To avoid a parallel execution if both tasks a kicked from one trigger you could implement a delay in one of the tasks maybe per sleep 60000; or something similar.

- Marcus

[kdmarkee]

Thanks for the advice.  I can say that both of my tasks calling the same set of qvds would not be executing Store statements, they would only be loading data into each qvw associated with those tasks.  So with that said, it should be ok, right?

[marcus_sommer]

I have had already file-locks by parallel read-access and therefore I would try to avoid it (maybe there are some dependencies to this behaviour regarding to any settings within the filesystem or something else - I don't know).

Another point to consider is if there are enough system-resources (CPU + RAM + Storage Performance) to handle both tasks parallel respectively to save a significantly amount of time. If there is any bigger bottleneck on this you might not save any time else it could happens that the run-times are longer.

- Marcus

[kdmarkee]

Other good points I didn't think of, thanks again.  I'll take your advice and avoid simultaneous loads using the same qvds.