Hi,
While trying to understand how our gerrit+jenkins setup works, I realized of a possibility of allowing bugs to get in.
Currently, our gerrit is setup to have cherry-pick as the submit type. Now consider a case where:
Dev1 sends a commit B with parent commit A(A is already merged).
Dev2 sends a commit C with parent commit A(A is already merged).
Both the patches get +2 from Jenkins.
Maintainer merges commit B from Dev1.
Another maintainer merges commit C from Dev2.
If the two commits B and C changed code which had no merge conflicts but were conflicting in logic,
then we have a master which has bugs.
If Dev3 now sends a commit D with re-based master as parent, we have the following cases:
1. If bug introduced above is not racy, we have tests always failing for Dev3 on commit D. Tests that fail would be from components that commit B and C changed. Dev3 has no idea on how to fix them and has to enlist help from Dev1 and Dev2.
2. If bug introduced above is racy, then there is a probability that Dev3 escapes from this trouble and someone else will bear it later. Even if the racy code is hit and test fails, Dev3 will probably re-trigger the tests given that they failed for a component which is not related to his/her code and the bug stays in code longer.
The most obvious but not practical solution to the above problem is to change the submit type in gerrit to "fast-forward only". It would then ensure that once commit B is merged, Dev2 has to re-base and re-run the tests on commit C with commit B as parent, before it could be merged. It is not practical because it will cause all patches in review to get re-based and re-triggered whenever a patch is merged.
A little modification to the above solution would be to
- change submit type to fast-forward only
- don't run any jenkins job on patches till they get +2 from reviewers
- once a +2 is given, run jenkins job on patch and automatically submit it if test passes.
- automatically rebase all patches on review with new master and mark conflict if merge conflict arises.
As a side effect of this, Dev would now be forced to run a complete regression on dev machine before sending a patch for review.
Any thoughts on the above solutions or other suggestions?
Thanks,
Raghavendra Talur
_______________________________________________ Gluster-devel mailing list Gluster-devel@xxxxxxxxxxx http://www.gluster.org/mailman/listinfo/gluster-devel
