On 06/03/2018 19:44, Marko Obrovac wrote: > Hello, > > Today during the scheduled deploy window of moving JobQueue jobs from > the Redis-based infrastructure to the new EventBus-based one, a > combination of PEBKAC and Gerrit trying to be smart caused an accidental > merge of the mw core's master branch into wmf.23. Luckily, the mistake > was spotted before the wmf.23 branch got updated on tin, so the blast > radius was limited to delaying the Euro-SWAT window by 30 minutes~[1]. > Big thanks to Antoine and Giuseppe for their help in discovering and > resolving the issues. > > You can read the full incident report here~[2]. The TL;DR is that > currently MW core repository is configured in such a way so as to allow > Gerrit to do implicit (and silent!) merges, even for cherry-picked > change-sets, which is something we might want to change in the near future. > > Cheers, > Marko > > [1] Thanks, James F, for patiently waiting on the resolution! > [2] > https://wikitech.wikimedia.org/wiki/Incident_documentation/20180306-MasterMergedInWMFBranch > > Marko Obrovac, PhD > Senior Services Engineer > Wikimedia Foundation
Hello, That Gerrit feature has been disabled by default for all repositories by setting receive.rejectImplicitMerges = true in All-Projects. https://gerrit.wikimedia.org/r/#/c/416704/ Implicit merging of a branch into another might be helpful sometime, but most probably all typical use cases would be due to a mistake and could lead to a catastrophe. I blame Gerrit default behavior on that one :] I would like to thanks Marko and Petr to have followed the deployment guide: * always check current workspace and remote before rebasing: git remote update git log HEAD..HEAD@{u} * halt immediately and ring the bell in case of doubt. Surely have ~90 unwanted commits was a red alarm. Thank you! -- Antoine Musso _______________________________________________ Services mailing list Services@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/services
