Connection lost issue

[user467341]

Hi Qlikers,

I have migrated my Qlik Sense to a AWS EC2 and most of the stuff has been working so far.

However, I faced an issue with apps having "An error occurred - connection lost. Make sure Qlik Sense is running properly. If your session has timed out due to inactivity, refresh to continue working.". This happens when I use Qlik Sense via HTTPS (issue does not appear if I login to a local account inside the EC2 itself).

Funny is, QS Hub does not have this error. Only when going into the app. I have already whitelisted the URL in the virtual proxies in QMC.

Any idea how to troubleshoot or fix this?

Thanks.

[Lucas_Gatling]

@user467341  please take a look at this KB article: https://community.qlik.com/t5/Official-Support-Articles/quot-An-error-occurred-Connection-lost-quot-... and see if you see the entries from the logs pertains to your issue. 

[user467341]

Hi,

In my log, I saw two errors:

Level: INFO - Audit.Proxy.Proxy.Communication.WebSocketProtocol.ProxyWebSocketFactory

Level: WARN - Audit.Proxy.Proxy.Core.Connection.Validation.ConnectionDataValidator

I saw there are alot of WARN showing Http request Host is not allowed.

I looked through the article, and have already whitelisted the URL xxxxx.com. What else can I do to troubleshoot this? Could this be related to the websocket getting terminated early due to some kind of security?

NOte: This only happens to App, and not HUB.

[user467341]

Hi all,

Any insights into this?

I did the Qlik Sense Websocket Connectivity Tester in the server and client and all are GREEN.

THank you.

[Albert_Candelario]

Hello,

Is there any Network & Security parameter from AWS that could be impacting the traffic of your EC2 machine?

Do you see anything on the Dev Tool of the browser? Is the WebSocket that gets closed?

Cheers,

Albert 

[user467341]

Hi Albert,

The only thing I saw in Dev Tool console was:

• DevTools failed to load source map: Could not load content for https:// xyz.com /customdata/64/QvWebStorageProviderConnectorPackage/web/Utils/spinner/conn-util-spinner.js.map  : HTTP error: status code 404, net::ERR_HTTP_RESPONSE_CODE_FAILURE
• Error loading connector, retrying: undefined

In the Network "WS", the status of WS is 101.

What I noticed is that the connection is always lost after 1 minute going into the App. Does this link to the ticket validity?

[Albert_Candelario]

Hello @user467341,

If the connection is lost after 1 minute it does not looks like a Qlik Sense client managed behavior, but some 3rd party component interfering it.

Are you using any Load Balancer in AWS?

Is your internal IT also fully engaged investigating the network?

Cheers,

Albert

[user467341 · Accepted solution]

Thanks Albert. Problem resolved as its IT related. 🙂

[Albert_Candelario]

Excellent, what was it? would be great to have some high level input 🙂

[jamielim]

Hi @user467341 are you able to advise what IT had to do to resolve this?