Slower performance of QlikView, after upgrade of QV 11.2 to QV 12.2 SR4

[ponchoorozcodiq]

Hi everyone,

A few days ago we did an upgrade of QlikView in the server of our clients. The client reports that, after the upgrade, all the reload tasks are taking more time than the usual and the CPU usage is up to 80% most of the time and reaching 100% in some moments. Before the update, the CPU was working way better and not overloaded.

We did some research and noticed that since QV12 the engine is now based on QIX, the Qlik Sense associative engine. Also, we find in the Release Notes of QlikView 12.00, that due to the changes in the QIX engine there are performance differences between QlikView 11.20 and QlikView 12.

Are these performance differences still being a known issue for QlikView 12.20 SR4?

Thank you in advance.

Alfonso Orozco

[Chip_Matejowsky]

Correct, QlikView v12+ utilizes the Qix engine.

Have you reviewed the 12.20 system requirements/release notes?

Which QlikView service are you experiencing memory/CPU issues with - QVS? QDS? Both?

[Miguel_Angel_Baeyens]

If the experience is worth for you, after extensive testing (including the scalability tools) we measured performance of the same app in 11.20 SR15, 12.20 SR3 and 12.10 SR9 simulating the users going to the AccessPoint, open time, clicking on easy expressions, clicking on heavy expressions and reload time.

For the reloads, a single task uses considerably more resources and reduces the overall duration by a third in the best case, which is very good.

In our case, a task, running just fine in 11.20, was taking 100% of CPU for several minutes in both version of 12. This was logged with Support, and their recommendation was to lower the CPU thresholds in the new settings (since CPU affinity for the Distribution Services no longer works: QDS will use as many CPUs as available in the computer, no matter what) and also lower the number of concurrent tasks, so there are less tasks running at any point in time but those tasks finish faster because the new QIX and improvements and because they don't have to compete for CPU resources.

Still, this is a risk: having your CPU at 100% for several minutes does not allow basic tasks at OS level like accepting new terminal services connections.

Not only that, you can clearly see in the task history in the QMC how the same app reloads in 6 minutes today and in 16 minutes tomorrow, depending on whether or not there were other tasks running at the same time. Which in addition to performance it's a hurdle when you have scheduled tasks that in 11.20 were consistently taking the same time to load, every day.

Additionally, if your customer servers, like ours, run in Amazon Web Services, Google Cloud or Microsoft Azure or similar, be aware that depending on their contract, since the resource usage is higher, also the costs could be higher, so use reserved instances.

I would love to have all environments for further testing but unfortunately it's not the case and we cannot spend time, but having back the CPU Affinity setting for the Distribution Service would not harm, for sure.

So please log a case with Qlik Support and if you can provide these tests and even the scripts to Qlik can reproduce on their own computers.

[sagarmehta1987]

Hi All,

We are also stuck with the same issue where the task reload time has increased. Is there any support suggestion or we need to upgrade it to different version where this issue is resolved?

We are on Qlikview November 2017 SR7 version