OpenJDK: Dude, Where's My Changeset?
By kto on Apr 18, 2008
Developers are asking where the changesets are, reminds me of that movie Dude, Where's My Car?, "Dude, Where's My Changeset?"
So it seemed appropriate to bring up the "OpenJDK Integration Wheel" again and talk about how a changeset moves around:
Let's look at the changesets (fixes) pushed to the
Swing Team Area.
Let's pretend a changeset was pushed to the Swing area and is now publicly available.
Not picking on the Swing team, just didn't want to change the picture :\^)
Feel free to change the example from "Swing" to "Build" and the
Build Team Area.
And Then? Immediately, anyone in the Swing team can pull these changesets down and have access to them. Other developers from other teams could also pull from this Swing area to get the change, but that's a bit abnormal, certainly possible, just not normal.
And Then? Depending on the Integration Schedule these changesets will likely remain in the Swing Team Area until the official Swing integrator pushes those changesets into the Master area (the Integration Process).
And Then? Once integrated into the master area, the other teams still may not see these changesets until their own integrators choose to "sync up" or send these new changesets in the Master area into their own team areas. This "sync up" usually happens as a team integrator prepares for the integration, so based on the order in the Integration Schedule, it could be a day or many days before a team will see changes that have been pushed into the master area.
And Then? Even after the team area has the changesets, a developer won't see the changesets until he pulls the changesets into his own area.
So you can see how sometimes it's hard to find a changeset. Somewhat independent of the changesets flowing into the various team areas, the Release Engineering Team will use the Master area and attempt to create a promoted build, and if successful will create tags in the Master repositories to record what changesets were included in a promotion.
Some people will find this whole process frustrating, but there are some big advantages. The delay of the changesets getting into the Master area allows for the team most closely associated with the change to test and verify, from that team's perspective. Odds are that bad changesets will get caught by the team, and this protects the other teams. The process the team integrator goes through includes additional testing to verify the changesets being integrated are solid for everyone. It's not unusual for an integrator to run into a problem with his team's changesets, which again protects all the other teams from potential disasters. Granted, regressions will still happen, but really nasty regressions are usually caught early.
Hope this helps explain things.