topic Does Qlik Sense remember which app has been opened (cached) on which server? in App Development

Does Qlik Sense remember which app has been opened (cached) on which server?

SaturnV — Fri, 16 Dec 2022 08:36:13 GMT

Hi all,

so we have 2 different "internal" - Servers on which the users can open a Qlik Hub and open apps.

The users will connect via a virtual proxy that has both of the servers configured as proxy and loadbalancing nodes.
Both servers have set in their engine settings the app cache timeout to 28800 seconds (8h).

So if a user opens a big App (5GB) the first time of the day and it gets loadbalanced to internal server 1, the app takes a fair amout of time to open.
If the same user or another also opens the same App 15 minutes later, it will also open on Server 1 and this time it opens almost instantly because it has been cached.

Now lets assume someone also opens this app 2 hours later, it somehow gets opened on Server 2 and this time pretty slowly again, because it has not been cached on Server 2 yet.

Why does it not just open it again on Server 1 where it already has been cached?

Does Qlik Sense not have anything implemented regarding this type of loadbalancing?

(Both Servers are running the Repository, Engine and Proxy Service, and are on the Qlik Sense Enterprise February 2022 version)

Re: Does Qlik Sense remember which app has been opened (cached) on which server?

Ray_Strother — Fri, 16 Dec 2022 17:07:06 GMT

Hello ,

The resources below should assist you in configuring the app timeout:

1.Load Balancing in Qlik Sense Enterprise on Windows

https://community.qlik.com/t5/Official-Support-Articles/Load-Balancing-in-Qlik-Sense-Enterprise-on-Windows/ta-p/1715174

2. Load balancing

https://help.qlik.com/en-US/sense-developer/June2020/Subsystems/Platform/Content/Sense_PlatformOverview/Concepts/Load%20balancing.htm

3. Editing an engine

https://help.qlik.com/en-US/sense-admin/May2022/Subsystems/DeployAdministerQSE/Content/Sense_DeployAdminister/QSEoW/Administer_QSEoW/Managing_QSEoW/edit-engine.htm

Apps > App cache time

Re: Does Qlik Sense remember which app has been opened (cached) on which server?

SaturnV — Mon, 19 Dec 2022 12:13:27 GMT

Thanks @Ray_Strother for the answer.

So if I understood correctly, qlik does not know where which app is already open but distributes the apps by the round-robin algorithm.

Okay therefore I tried to distribute the apps via a load balancing rule to specific consumer nodes. I created a custom property "AppLoadbalancing" with two possible values "server1" and "server2".
I then set the custom property to the apps and the nodes and created the loadbalancing rule. In the preview everything looks fine. However it does not do anything and I don't know why. It still seems to apply the round-robin algorithm prioritized.

My Rule:

My custom property:

Do you have any idea what I am missing here?

Thanks and best regards
Julian