server crashing

[krishnjha]

we have 98 gb ram,

32 virtual memory 

cpu 2.32 ghz.

we have couple of reloading task running frequently. our server stop completely even with these reasources.

can anyone help me to optimize my qlik engine.

[Sooraj_Suresh]

@krishnjha 

Please provide us more insights into the environment setup and details.

-> Version of QlikSense

-> Multi node or single node?

-> How many apps are running in parallel? How big are the apps?

-> At what point of time does the server crashes?

-> Have you noticed any errors in event logs during the server crash time?

-> Which Qlik service utilizes the memory the most?

Best Regards

Sooraj Suresh  

[Maria_Halley]

@krishnjha

This can be normal QlikSense behavior.

QlikSense is an in memory application and it does consume a lot of RAM.

When you open an app on the server it gets loaded to RAM. The app seizes in RAM in not the same as on disk. It can be many times bigger in memory.

A 1 GB app could be 5-10 in RAM (or more), it depends on the data model and design of the document.

Once the apps are loaded it stays in memory until the app timeout has passed (default 8h). The appt timeout does not start to count down until all sessions against it is closed.

It is normal that the memory consumption stays high even if no one is logged in.

We also cache calculations and session information.  This does not get cleared when the app gets unloaded but stays in memory until the working set limit is reached.

Then we start to clear it out, started with the data that was used the longest ago.

When you run reloads the apps are also opened  (they close when reload is finished) 

This is done this way per design to get the best possible experience for the users.

For more details on this see

https://community.qlik.com/t5/Knowledge/QIX-Engine-Memory-Management-and-CPU-Utilization/ta-p/171618...

[krishnjha]

version may 2021,

single node,

max 3 parallel apps are running and maximum size is of apps is 1180 mb.

it crashes when memory utilization reaches 100%,

nothing specific has been recorded in log.

qlik engine uses most of the memory.

[krishnjha]

@Maria_Halley 

yeah maria, I understand this but my point is we need to have something specific. like how much ram should we have for certain size of app. We cant be black about any issue. 

we need to have some concrete solution to prevent this issue.

[Maria_Halley]

@krishnjha

I understand what you mean, but there are no way we can answer that question. All deployments are different, and there are just to many variables,  like, App size, data model, how many concurrent users, reload frequency etc. So to answer this question, without spending a lot of time going through all aspects of your QlikSense installation is impossible.

The scalability tools that can be used for testing.

https://community.qlik.com/t5/Knowledge/Qlik-Sense-Scalability-Tools/ta-p/1715051

If you want more help with this I suggest that you contact professional services. 

As part of a Professional Services engagement (paid services), you will get a dedicated PS resource to work with you remotely or in person, who will be able to answer your questions and work with you one-on-one on the implementation.