Can you provide more details that describe how you have enabled issue scanning with the warnings plugin? My initial guesses trying to duplicate the problem were not successful.

I've created over 200 branches on https://ci.jenkins.io/job/Plugins/job/xshell-plugin/ and am allowing it to run the jobs on those branches to completion. The load of starting and running 200 concurrent jobs that each require a Windows and a Linux agent for 2-4 minutes is certainly slowing response time, but it is a matter of seconds delay.

Those jobs are using recordIssues(). The script they are running is https://github.com/jenkins-infra/pipeline-library/blob/master/vars/buildPlugin.groovy

Now that the 200 jobs have all completed, when I open the jobs page, it takes about 15 seconds to finish loading the entire page. The page is already displaying in the first few seconds, but the "page loading' indicator in the browser tab shows that data is still arriving. The blue ocean page needs about 10 seconds to finish loading. A specific Pipeline run loads immediately.

We use the following step to scan for issues from a declarative jenkins pipeline:

recordIssues enabledForFailure: true, quiet: true,
  tools: [checkStyle(pattern: '**/build/reports/checkstyle/*.xml'), junitParser(
    pattern: 'frontend/coverage/**/junit.xml,**/build/test-results/**/*.xml,**/build/reports/ruleTests/**/*.xml'),
          java(), kotlin()] 

Many of the Branches where already scanned before upgrading to the warnings-ng version where we experienced the issues.
FlameGraph.zipcontains full cpu and allcation flame graphs in svg form.

Is there any additional information that I could provide that can help with reproduction / analysis?

We're experiencing similar sever performance issues on some multibranchPipelineJobs . The job in particular has a relatively high number in the "#issues" column (16000+). So my thought was there is something surrounding rendering that data.

We upgraded from 11.12.0 to 12.4.1. 

We see the same performance issue when there is a high number of issues (60.000+).

I can confirm that the issue is fixed with 12.5.0! Thanks a lot, drulli