Qlik Sense Engine - How the memory hard max limit works

[Bastien_Laugiero]

The Qlik Sense Engine allows for a hard max limit to be set on memory consumption.

Environment:

Qlik Sense Enterprise on Windows , all versions

Resolution:

The setting is located in the Qlik Sense Management Console > Engine > Advanced and can be configured as an option in the setting Memory usage mode.
See Editing an engine - Qlik Sense for administrators for details on Engine settings. 

• In the drop down list you can choose Hard Max Limit which prevent the Engine to use more than a certain defined limit. 
• This limit is defined by the parameter set in percentage called Max memory usage (%)

Even with the hard limit set, it may still be possible for the host operating system to report memory spikes above the Max memory usage (%).

The reason for that is because the Qlik Sense Engine memory limit will be defined based on the total memory available.

Example:

• A server has 10 GB memory in total and the Max memory usage (%) is set to 90%.
• This will allow the process engine.exe to use 9 GB memory. 
• Another application or process may at that point already be consuming 5 GB memory, and this will cause an overload of the system if the engine is set to use 9 GB. 
• The engine.exe will not be able to respect other services

The memory working setting limit is not a hard limit to set on the engine. This is a setting that set how much we allocate and how far we are allowed to go before we start alarming on the working set beyond parameters 

Internal Investigation IDs:

• QLIK-96872

[QFabian]

Excellent @Bastien_Laugiero , thank you

[aadil_madarveet]

Thanks for the article.

Could you please explain what happens if the max memory usage is reached in a multi-node cluster. If the memory usage one node 1 is at max usage, will the resources of node 2 be used to maintain user sessions and performance. My question is basically, does Qlik manage resources spill over to next available node for the same app.

Thanks,
Aadil

[AdamBS]

Hi

Does the help indicate that this Hard max limit is basically void unless the O/S adjustment is done?

https://help.qlik.com/en-US/sense-admin/February2024/Subsystems/DeployAdministerQSE/Content/Sense_De...

As per @aadil_madarveet when the limit is reached, what is the behavior of the engine?  Does it just restart?