Hi,

We have an upstream project(with configuration matrix) which trigers downstream one. Downstream project has "Throttle Concurrent Builds" option enabled with "Throttle this project alone", "Maximum Total Concurrent Builds=2", "Maximum Concurrent Builds Per Node=2"

Both upstream and downstream projects have "xUnit" related steps in "Post-build Actions"

Issue there is when we have triggered 10 concurrent builds(#100 - #109) of the downstream project and the third one (#102) requires more time to finish - all further builds (#103 - #109) will be locked until this third build finish.

Other example, when two builds there were executing simultaneously, one of them failed and took long time to finish.
It looks like successful one was waiting for unsuccessful one.

Just compare end of logs for these pairs of tests.
Pay attention on time stamps: gap between "Stopping recording" and "Sending e-mails":

jenkins/view/QA/job/_SIP/job/pjsip_c/2900/console
jenkins/view/QA/job/_SIP/job/pjsip_c/2901/console

11:07:30 [xUnit] [INFO] - Starting to record.
11:07:30 [xUnit] [INFO] - Processing JUnit
11:07:30 [xUnit] [INFO] - [JUnit] - 3 test report file(s) were found with the pattern 'results-pjsip/*.xml' relative to '/tmp/workspace/_SIP/pjsip_c' for the testing framework 'JUnit'.
11:07:35 [xUnit] [INFO] - Check 'Failed Tests' threshold.
11:07:35 [xUnit] [INFO] - The total number of tests for this category exceeds the specified 'failure' threshold value.
11:07:35 [xUnit] [INFO] - Setting the build status to FAILURE
11:07:35 [xUnit] [INFO] - Stopping recording.
11:07:35 Build step 'Publish xUnit test result report' changed build result to FAILURE
11:07:35 Sending e-mails to:
11:08:05 Notifying upstream projects of job completion
11:08:05 Join notifier cannot find upstream project: _SIP/pjsip_cron/VM=etsys,Version=390
11:08:05 Finished: FAILURE

VS

10:56:40 [xUnit] [INFO] - Setting the build status to SUCCESS
10:56:40 [xUnit] [INFO] - Stopping recording.
11:07:34 Sending e-mails to:
11:08:04 Notifying upstream projects of job completion
11:08:04 Join notifier cannot find upstream project: _SIP/pjsip_cron/VM=etsys_ora,Version=380
11:08:04 Finished: SUCCESS

And:
jenkins/view/QA/job/_SIP/job/pjsip_c/2904/console
jenkins/view/QA/job/_SIP/job/pjsip_c/2905/console

10:34:52 [xUnit] [INFO] - Starting to record.
10:34:52 [xUnit] [INFO] - Processing JUnit
10:34:53 [xUnit] [INFO] - [JUnit] - 3 test report file(s) were found with the pattern 'results-pjsip/*.xml' relative to '/tmp/workspace/_SIP/pjsip_c' for the testing framework 'JUnit'.
10:34:57 [xUnit] [INFO] - Check 'Failed Tests' threshold.
10:34:57 [xUnit] [INFO] - The total number of tests for this category exceeds the specified 'failure' threshold value.
10:34:57 [xUnit] [INFO] - Setting the build status to FAILURE
10:34:57 [xUnit] [INFO] - Stopping recording.
10:34:57 Build step 'Publish xUnit test result report' changed build result to FAILURE
10:34:57 Sending e-mails to:
10:35:36 Notifying upstream projects of job completion
10:35:36 Join notifier cannot find upstream project: _SIP/pjsip_cron/VM=etsys_ora,Version=390
10:35:36 Finished: FAILURE

VS

10:21:28 [xUnit] [INFO] - Setting the build status to SUCCESS
10:21:28 [xUnit] [INFO] - Stopping recording.
10:34:57 Sending e-mails to:
10:35:31 Notifying upstream projects of job completion
10:35:31 Join notifier cannot find upstream project: _SIP/pjsip_cron/VM=etsys,Version=371
10:35:31 Finished: SUCCESS

Could you please advise how we can workaround this issue. Any help is appreciated.