Hi, James. On Tue, Mar 2, 2010 at 9:05 AM, James Westby <[email protected]> wrote: > Hi, > > With the addition of bug heat there's a danger of a little trap being > inadvertently set for those using the API. > > If bug_heat is exported as an attribute over the API then it goes in to > the calculation of the etag for a bug. That means that bug_heat, like > status, importance, etc. can't change between GETting the bug over the > API and PATCHing new values to it.
IBug.heat is already exported. > > However, as bug_heat is decayed using cron it will race with all > modifications done over the API, meaning that you will occaisionally get > 412 errors from your scripts. > > There would be a couple of ways of fixing this, such as exporting > bug_heat as a method not as an attribute. I'm open to avoiding 412 errors, certainly! I don't know that I like the idea of converting heat to a method. Seems like a hackish thing to do, simply because getting a 412 is a pain. We're only going to be hitting this more and more as we continue to expose attributes in the API. I think we would be better to solve the root problem. > > We already have something like this with, at least, code, where you race > with the scanner when pushing up a branch and then modifying an > attribute of the branch over the API. > > You could argue that script authors should deal with 412 errors, as they > can happen with concurrent user edits and the like. While that is true, > I'm not sure we need to be making it more likely to happen, and racing > with automated tasks is less or a reason to conflict anyway. Plus, the > facilities for handling conflicts in the API are lacking from where they > should be if all API users should be dealing with them. > I agree we should have facilities for dealing with the 412 error better in launchpadlib. I also think it would be nice to be able to mark an attribute as ignorable for the sake of calculating the etag when we decorate attributes for exporting. If status on a bug changes, that could matter to a script. If heat changes, not so much. Heat can't be set by an external script anyway. I wonder if read_only does this or could be made to do this? I asked Leonard on IRC and he wasn't sure. He's also very busy at the moment to dig further into the question. This seems a nice solution. But it doesn't solve it for attributes that can be set. Maybe we could provide hooks in launchpadlib for a script to indicate this, i.e. generate me a 412 if bug status changes because I'm working with that, otherwise let me do my work in peace. I think it's worth fixing these issues, or others like them, rather than trying to do hacks to prevent something affecting the etag calculation. But I do realize these issues fall to Leonard often, so I don't mean to shirk my responsibilities either. :-) Cheers, deryck -- Deryck Hodge https://launchpad.net/~deryck http://www.devurandom.org/ _______________________________________________ Mailing list: https://launchpad.net/~launchpad-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~launchpad-dev More help : https://help.launchpad.net/ListHelp
