2 Replies Latest reply: Feb 14, 2016 12:56 PM by Markus Anttila RSS

    ERR_CONNECTION_TIMED_OUT

    Markus Anttila

      Hi guys,

       

      Building a quite large mashup with multiple angular directives sending multiple request to the qlik sense api. When loading the page I sometime (quite frequently) get the message ==>

       

      WebSocket connection to 'ws://URL?reloadUri=URL' failed: Error in connection establishment: net::ERR_CONNECTION_TIMED_OUT

       

      Im guessing its do to simultaneous request at the same time, thinking wrapping some of the calls in a $timeout maybe?

       

      Does anyone have any knowledge of this or prior experience on the most subtle way to fix it?

       

      Thanks

        • Re: ERR_CONNECTION_TIMED_OUT
          Alexander Karlsson

          Hmm, is each directive establishing a websocket connection? Then you might be running in to websocket limitations, IE can only establish 5 concurrent socket connections for example.

           

          The best practice would be for your app to move the connection to a angular service and then depend on that in your controllers to re-use the same socket.

           

          Another thing to check for, is your server exposed to the internet with a DNS name?
          In 2.1 we had a bug related to TLS 1.0 connections. So after the POODLE exploit was announced hackers are scanning the web for sites accepting TLS 1.0 connections and then they try to execute the exploit. Once the attacking request hits the Qlik Sense Proxy service we see that it's a malicious request but instead of just discarding it we also shut down the Proxy. That's usually when you see the timed out errors on the socket, a reboot of the services fixes it.
          To see if you are affected, open the Event Viewer on the server, go to the Windows > System logs and check for SChannel errors. If you have any then you are most likely affected.

            • Re: ERR_CONNECTION_TIMED_OUT
              Markus Anttila

              Hi Alexander and thanks for your reply,


              The issue was that i accidentally had two services calling the api creating two websockets.

               

              Also, how does Qliksense (proxy.exe) tackle the max amount of open connections and what is the mechanism proxy.exe uses to close the connections after a certain amount of time of user inactivity?

               

              Thanks for your help.