Extreme chaining of v- parameters in URL

Hi, it occured for us on Vaadin8 in production environment that ‘v-’ parameters in URL started to chain indefinitely (new v- param was added to URL approx in the pace of the heartbeat) and at the end the user was disconnected. We did not have chance to observe the behaviour in browser, user described it that the blue progress bar at top of screen was making many short rounds.
e.g. POST /web/?v-1677663941338&v-1677663989764&…
This never occured before (or at least 3 months back not once).
Please, is this a known issue?

(We are also investigating other possibilities like interaction of on-premise infrastructure or monitoring tools)

Is it possible that there are multiple v- parameters in the URL? Can we request that the on-premise firewall drops every request with multiple v- params?

This looks like the height/width Browser resize could be triggered a little bit often

Nope, every “starting” request has literally 10-15 such params. If you open your app and look with devtools you can see the initial request with all those params


So you are saying that it is a legitimate and correct Vaadin request that contains multiple v- params and we should NOT drop such requests.

Yes the initial request of a UI is exactly like this

That is streange, I grepped our logs for past 4 months and could not find a single request with multiple “v-TIMESTAMP” params…

There should not be multiple “v-with-the-same-name” tho, each param is unique if I remember correctly

There are not such params normally

Only 1

Ahh! Those were post params… I’m referring to. Damn long time ago…

Just wondering… is your service accessible from the internet?

Knoobie, thank you very much for your effort, but we would like to get answers to the queastions I posted. Whether it is a know issue. Whether we can safely drop every request that has multiple ‘v-’ params.

If you have a license for extended maintenance for V8 you are better off asking the expert chat or sales person. There are no public reports about such behavior in the last months.

Yes, i will, thank you. I need to leave now and will check for reply later. See you.

FYI it was caused by a client’s monitoring tool or department gone wild