Enabling TCP Keep Alive Functionality In Qlik SenseArticle Number: 000055708 | Last Modified: 2019/05/20
This option is available in Qlik Sense June 2018 Patch 1 and later releases.
We are getting errors "Connection to the Qlik Sense engine failed for unspecified reasons. Refresh your browser or contact our system administrator" for external users on other browsers except for IE when they open the Qlik sense app and leave it IDLE until it exceeds the Firewall session idle timeout and followed by a connection reset on TCP WebSocket.
Note:- No issues found with IE because it sends the TCP Websocket keep-alive.
The web socket functionality is default delivered switched off not to affect any existing customers. Customers who don't experience any issues with web sockets terminated by the network due to inactive SHOULD NOT switch this feature ON since it will send unnecessary traffic on the network.
How to configure?
1. Stop the Qlik Sense Proxy Service
2. Edit the file C:\Program Files\Qlik\Sense\Proxy\Proxy.exe.config
3. Add key
<add key="WebSocketPingInterval" value="0"/> <!-- Interval in seconds for the web socket ping to the client (a value of "0" is disabling the ping)–>
Where value is a suitable positive number depending on the inactive web socket timeout setting in the network.
Recommended is 60-300 second range, shorter interval generates more load on Proxy CPU and network. It should be set as high as possible, meaning it's best to identify at which interval an intermediate proxy cuts the connection when it perceives it as idle, and then set the ping interval to a slightly smaller value.
A too small number (e.g. less than 30) will load the proxy and the network and IS NOT recommended. Suitable numbers could be 60 to 300 (i.e. 1 minute to 5 minutes), but it all depends on the network configuration (if the network removes web sockets that have been inactive for more than 5 minutes then, of course, the value must be set something less than 5 minutes (i.e. less than 300)). If a lower value is required, it is recommended to investigate the components involved in the connection, such as third party proxies and network loadbalancers to configure them with less restrictive timeouts.
3. Restart the Qlik Sense Proxy Service.
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