Connection Lost Error in Iframe with Reverse Proxy

[manish_2991]

Hi Team
We have encountered an issue while deploying the Qliksense IFrame URLs on a portal.
We are getting the error message 'Connection lost. Make sure that Qlik Sense is running properly. If your session has timed out due to inactivity, refresh to continue working'.
At first when we logged in to portal, page loads perfectly but after few seconds a pop comes for 'An error occurred' with the above mentioned message.
We have configured the reverse proxy in Portal for Qliksense and using SSO for login.
On checking the log files (Audit Activity Proxy log) - whenever the user is logged in getting the status as 'Open connection 0 Backend web socket connection Opened for session' but after few seconds getting the status in logs as 'Close connection 0 Backend web socket connection Closed for session'.
We have changed the values for 'Keep-alive timeout (seconds)' in proxy of QMC from '10' to '30'  and 'WebSocketPingInterval' from '0' to '300' in Proxy.exe but still no luck.

Unable to check using wireshark tool as tool is not allowed to be installed.

Please guide.

@Sonja_Bauernfeind @Andre_Sostizzo 

[Nick_Asilo]

@manish_2991 

If you haven't already I advise testing the functionality bypassing the Reverse Proxy test using the Fully Qualified Domain Name of the QS server directly. Also, confirm WebSocket connectivity through the Reverse Proxy.

The "Backend web socket connection Closed for session" string seen in the logs is registered when a WebSocket TCP layer connection is closed by the transmission of a TCP Packet containing the FIN flag set. This indicates the Reverse Proxy is shutting off the communications prematurely, which is why it is advised to work with the networking team to investigate the particulars of the behavior.

If your organization does not permit the use of Wireshark, work with your management, networking, and security team to find a tool or method that will work best for you and your organization's restrictions.

That said, if the error is happening after only a few seconds I really recommend reviewing the settings of the Reverse Proxy. You can try reducing the WebSocketPingInterval to a smaller value, we generally advise not going lower than 30 seconds and if you get the error sooner than that it will not be caught by the ping. It's possible to set it lower but this creates more network traffic and thus I advise reviewing the network components between the client and Qlik Sense.

Hub access times out with: Error Connection lost. Make sure that Qlik Sense is running properly 

Enabling TCP Keep Alive Functionality In Qlik Sense 

Qlik Sense Enterprise hub timeout even with session timeouts configured correctly 

Qlik Sense Websocket Connectivity Tester