topic Re: Connection lost issue in Management & Governance

Connection lost issue

user467341 — Mon, 15 May 2023 09:25:02 GMT

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.

Re: Connection lost issue

Lucas_Gatling — Mon, 15 May 2023 12:25:43 GMT

@user467341 please take a look at this KB article: https://community.qlik.com/t5/Official-Support-Articles/quot-An-error-occurred-Connection-lost-quot-or-quot-Bad-Request/ta-p/1712695 and see if you see the entries from the logs pertains to your issue.

Re: Connection lost issue

user467341 — Mon, 22 May 2023 06:08:33 GMT

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.

Re: Connection lost issue

user467341 — Mon, 22 May 2023 07:13:42 GMT

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.

Re: Connection lost issue

Albert_Candelario — Mon, 22 May 2023 09:04:14 GMT

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

Re: Connection lost issue

user467341 — Mon, 22 May 2023 09:51:21 GMT

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?

Re: Connection lost issue

Albert_Candelario — Tue, 23 May 2023 07:27:44 GMT

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

Re: Connection lost issue

user467341 — Tue, 23 May 2023 08:53:56 GMT

Thanks Albert. Problem resolved as its IT related. 🙂

Re: Connection lost issue

Albert_Candelario — Tue, 23 May 2023 12:38:58 GMT

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

Re: Connection lost issue

jamielim — Wed, 06 Mar 2024 06:51:47 GMT

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

Re: Connection lost issue

sagouramD — Wed, 12 Jun 2024 08:25:48 GMT

Hello @user467341 could you please share the solution that worked on your side ? We are facing the same issue wiuth the same WARN in regards to the host not being allowed even tough only the FQDN is in the whilelist allow.