topic Re: Users Experiencing Frequent "An error occurred. Connection lost" Messages - Qlik Sense in Connectivity & Data Prep

Users Experiencing Frequent "An error occurred. Connection lost" Messages - Qlik Sense

matthewharrison — Fri, 04 Nov 2022 13:49:03 GMT

It has been raised to our attention that some users have been experiencing frequent Qlik Sense timeouts with the message of:

"An error occurred - Connection lost. Make sure that Qlik Sense in running properly. If your session has timed out due to inactivity, refresh to continue working. "

Users claim that it is taking just a couple minutes to timeout on a Qlik report, and even when they are actively using it, not only when inactive. We have also experienced this issue ourselves as admins, with reports giving connection error messages while we are using them. When not using them, the connection error will always appear within 5 minutes or so.

After checking our proxies and networking settings in QMC, we can't find any settings which would indicate this, and inactivity timeouts are set to 15+ minutes so that is not it either. The underlying infrastructure running our Qlik server has has zero unscheduled downtime and does not involve and complex networking infrastructure - only an app service plan in Azure. Has anyone else experienced something like this?

Re: Users Experiencing Frequent "An error occurred. Connection lost" Messages - Qlik Sense

Jay_Brown — Tue, 01 Nov 2022 20:38:19 GMT

Hello @matthewharrison , what's the full version that you are seeing this on?

Re: Users Experiencing Frequent "An error occurred. Connection lost" Messages - Qlik Sense

matthewharrison — Fri, 04 Nov 2022 13:47:17 GMT

We are currently running Qlik Sense Server version 14.67.11 (May 2022 Patch 2).

Also We have observed the issue becoming more prevalent with timeouts even for the admins happening in about 4-5 minutes, so we know this is not an issue of republishing apps.

Re: Users Experiencing Frequent "An error occurred. Connection lost" Messages - Qlik Sense

Jay_Brown — Fri, 04 Nov 2022 15:31:35 GMT

Hi Matthew, thanks for the update.

Based on the 4-5 minute description this sounds as if it is an issue with sticky sessions.

Please see the following:
https://community.qlik.com/t5/Deployment-Management/Session-Timeout-Connection-Lost/td-p/1548837
https://community.qlik.com/t5/Integration-Extension-APIs/Set-up-for-Multinode-site-avoiding-session-timeout/td-p/1860635
https://community.qlik.com/t5/Official-Support-Articles/Network-Load-Balancer-NLB-Requirements-for-Qlik-Sense-Enterprise/ta-p/1715665
https://community.qlik.com/t5/Official-Support-Articles/How-to-configure-Network-Loadbalancer-NLB-with-Qlik-Sense/ta-p/1714144

Please check with your internal network teams to check the session configuration on any network load balancers, it is very common for these to be set at 5 minutes (default on some vendors) and as Sense requires persistent sessions, you'll see this error.

Thank you!