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.NetSdk - Connection failed after 4 attempts

Hi Guys,

we use .NetSDK to integrate QlikSense in an ERP - system. Now we are faced with following problem:

     We are not able to cache the Location or the Connection, so we have to connect us with the QlikSense Server several times. But      after these attempts an error occurs:

Exception NAVdiscovery.png

It also affects the hub. The user has no access.

2015-09-22 10_09_53-Qlik Sense.png

Do you have a solution for this issue?

(I reconstructed this with the engine API, but there is a similar problem. After several method calls I receive an errormessage, which includes the information, that the server has canceled the connection)

Thank you

René

17 Replies
Not applicable
Author

Thank you for clarification.

Not applicable
Author

Dear Lars-Goran,

Sorry for re-opening this topic again. We've been trying to get this implemented in our app but we are still struggling with the Location not being disposed properly. In our case we are not able to create the location with "using" because actually the Qlik.Engine.Location class is not disposable.

Is there any alternative for doing this? We have been trying removing the session via REST request or using different ways of connecting the location but it still returns the timeout after 5 connections one after the other.

We will appreciate your help on this as we have been stuck for a few days already. Thank you!

Lucas Stiefel

Not applicable
Author

Hi,

Which version of the SDK are you using? In the SDK version 2.x and 3.x have the Location have a Dispose method. In this Dispose method there is a REST call to do the logout. But be aware that the Proxy Session has a 5 min timeout which means that the session will be blocket for 5 min after dispose.
The best way to handle multiple calls is to keep the session alive all the time for example keeping it in a windows service.

Best Regards

Lars-Göran Book

Not applicable
Author

Dear Lars-Goran,

I don't understand why it's neccessary to block the sessions after dispose. Are there considerations to change this behaviour in future?

Best regards

René Engler

Anonymous
Not applicable
Author

Hi Lars-Göran,


Do you have any example how to keep the session alive using .NET?


Many thanks!


BRs,

Michal

Øystein_Kolsrud
Employee
Employee

Do you mean you would like to use the SDK to avoid the "Session timed out" message in the client? If that is the case, then I think you could force that behavior by making sure you trigger some form of change notification that the client will react to. I experimented with a small loop that just updated the name of the app every now and then, and then I didn't get that time out. But you probably want to trigger some notification that doesn't really modify anything I guess. Perhaps you could do something with selections? Perhaps you could do some random selection and then do "app.Back()" to go back to the previous selection?

You could also hook into the change notification of the app from the SDK and make sure you only do this operation only when needed.

Anonymous
Not applicable
Author

Hi Øystein,

Thanks for your response!

I'm working on the web page that loads data from sql tables to Qlik (i.e. change table name in the load script and reload). There is a dropdown list with available Qlik apps populated via Qlik API. When the user refreshes/posts the page the new proxy session is created. After 5 refreshes I get LicenseAccessDenied exception due to limit of 5 sessions. As I understand ILocastion.Dispose does not kill the session. I also tried to add REST call to logout but with no success. So I'm wondering how to terminate the session after each page load or to keep the session so the new one is not created each time.

try

            {

                // Open location

                using (ILocation location = Qlik.Engine.Location.FromUri(qlikConfig.QlikEngineUri))

                {

                    // Define the location as a connection to Qlik Sense using NTLM Authentication

                    await location.AsNtlmUserViaProxyAsync();

                    // Add all available apps to the list                              

                    foreach (IAppIdentifier appIdentifier in await location.GetAppIdentifiersAsync())

                    {

                        apps.Add(new QlikApp() { Id = appIdentifier.AppId, Name = appIdentifier.AppName });

                    }

                    /* LOGOUT REST TEST */

                    var proxyPath = "";

                    if (!string.IsNullOrEmpty(location.VirtualProxyPath))

                    {

                        proxyPath += location.VirtualProxyPath + "/";

                    }

                    var serverPath = $"{location.ServerUri.AbsoluteUri}{proxyPath}";

                    var request = (HttpWebRequest)HttpWebRequest.Create($"{serverPath}qps/user");

                    //var request = (HttpWebRequest) HttpWebRequest.Create($"{location.ServerUri}qps/{proxyPath}session/{sessCookie[1]}");

                    //var reques = (HttpWebRequest)HttpWebRequest.Create(serverPat + "/user");

                    request.CookieContainer = new CookieContainer();

                    foreach (var cookie in location.CustomUserCookies)

                    {

                        request.CookieContainer.Add(new Uri(serverPath), new Cookie(cookie.Key, cookie.Value));

                    }

                    var sc = location.SessionCookie.Split('=');

                    request.CookieContainer.Add(new Uri(serverPath), new Cookie(sc[0], sc[1]));

                    request.Method = "DELETE";

                    var res = request.GetResponse();

                }

            }

Many thanks!

BRs,

m

Øystein_Kolsrud
Employee
Employee

I'm afraid the licensing and session management is outside of my main area of expertise. And I believe the "license denied" behavior you refer to is also highly dependent on what the licensing scheme is in your environment. I hope someone else can chime in and help you here.