We Azure DevOps Server 2020 on-prem. And I noticed that I cannot open more than just a few Azure DevOps builds in different Chrome tabs concurrently. Namely, here is what I am doing:
- Navigate to an Azure DevOps build and wait until all the details are loaded.
- Repeat step (1) for another build
What I have noticed is that after 5-1 tabs (sometimes I am "blessed" with 5 fully loaded tabs and sometimes I cannot have more than 1) no new tabs are able to load the build details. I am using builds as an example, could be PRs or other screens.
At first I thought we have some concurrency limit on the server, but we do not. Neither IIS nor the Sql Server serving the requests have any concurrency limit defined. But then, I have discovered an even weirder thing - this concurrency limit exists in Chrome and Edge, but not IE!
I do not want to make IE my default browser, I would prefer keeping Chrome. But this drives me crazy.
My current theory is that it has to with signalr. Azure DevOps frondend uses some kind of signalr implementation. Maybe Chrome and Edge are too "advanced" to handle it correctly? Or maybe IE does not handle it at all and so Azure DevOps server fallsback to something IE supports and as a result no throttling is experienced?
I am pretty lost here and have no idea how to troubleshoot it further. Any ideas?
EDIT 1
Initial inspection of the URLs visited from chrome vs IE shows a difference in signalr urls:
- IE: transport=webSockets
- Chrome: transport=serverSentEvents
Does it make sense to anyone? Could this difference explain why Chrome is unable to open more then 1-5 (1 sometimes happens in the evenings) tabs serving Azure DevOps Server 2020 web pages?
EDIT 2
Right at this moment the limit is 6. I have 6 tabs open on the same exact build, 7th is hanging. The Network tab in the browser shows it is being stuck on the very first server side request to http://theserver:8080/tfs/DefaultCollection/SharpTop/_build/results?buildId=1184073&view=logs&j=ca395085-040a-526b-2ce8-bdc85f692774. No response at all. But if I close any of the other 6 tabs, it would load immediately.
EDIT 3
Posted on the MSFT Dev Community site - https://developercommunity.visualstudio.com/t/unable-to-load-more-then-6-sometimes-less-tabs-of/1466416