Is it necessary to restart the Qlik sevices now and then for better qmc performance?
Recently, I faced an issue with my task schedulers. The tasksin qmc that regularly update my various applications suddenly started working slowly. It was so slow that a task which was taking 3hrs to complete was suddenly taking 6 hrs. There were no errors also in log files and the only difference in logs was that 'Reloading' piece now runs for about 6 hrs instead of 3 hrs. This case was similar for all the schedulers. I did quite a bit of research but couldn't conclude anything significant. Finally, I restarted the qlik services in server and from then on everything was back to normal.What could be the explanation for this?
I would like to know that is it imperative to restart your services after a certain period? Is it necessary to include restarting of services in your regular maintenance activities?
Re: Is it necessary to restart the Qlik sevices now and then for better qmc performance?
Most probably, your QVS service has been eating RAM like candy, up to the Max Working Set Limit. QDS (the distribution service) does the reloads as a set of processes outside of QVS. As a result, QDS may find that most of the machines RAM has been allocated to to QVS and because of too few memory bytes available for doing in-memory reloads will start paging to disk. That's the cause ot the slowdown.
You can either:
buy more RAM and tune the Working Set limits so that QVS doesn't run off with all of precious memory
restart the QVS service before the big reloads are launched (for example at night)