Status: Closed (View Workflow)
We have a freestyle job (named config_job) that configures other freestyle jobs on the same jenkins via REST. In some of these freestyle jobs the config_job is added as a reverse build trigger and thus some jobs become downstream jobs of the config_job. We noticed that sometimes these newly added downstream jobs are not built.
After looking at the jenkins source code, we noticed the following TODO in BuildTrigger.executes:
// TODO this may not yet be up to date if rebuildDependencyGraphAsync has been used; need a method to wait for the last call made before now to finish final DependencyGraph graph = Jenkins.get().getDependencyGraph();
Since the dependency graph is still rebuilding when our config_job finishes, an old version of the dependency graph is used which does not include the reverse triggers we just added and thus some downstream jobs are not built.
JENKINS-68189 Downstream jobs are no longer executed (regression in 2.341)
My earlier comment were accidentally deleted - This issue needs to be reopened because the fix for this introduced another bug - if the downstream child job is build on a slave node and the parent job is set to build on a master node, the child job would not run at all and the master node has no record of the job even being triggered.
We propose the following fix:
BuildTrigger.executes waits until the dependency graph has settled. To detect if the dependency graph has settled, we add a getter for dependencyGraphDirty in Jenkins.java.
We then modify rebuildDependencyGraphAsync() in Jenkins.java in such a way that only one job can be scheduled for rebuilding the dependency graph. If this method is called while the dependency graph is still rebuilding, the current run is canceled and a new run is started.