On Fri, Dec 28, 2018 at 8:39 PM Konstantin Ryabitsev <konstan...@linuxfoundation.org> wrote: > > On Sat, Dec 29, 2018 at 03:56:21AM +0000, Eric Wong wrote: > > Hey all, I just added this to the TODO file for public-inbox[1] but > > obviously it's intended for git.git (meta@public-inbox cc-ed): > > > > > +* Contribute something like IMAP IDLE for "git fetch". > > > + Inboxes (and any git repos) can be kept up-to-date without > > > + relying on polling. > > > > I would've thought somebody had done this by now, but I guess > > it's dependent on a bunch of things (TLS layer nowadays, maybe > > HTTP/2), so git-daemon support alone wouldn't cut it... > > Polling is not all bad, especially for large repository collections.
I disagree with that statement. IIRC, More than half the bandwidth of Googles git servers are used for ls-remote calls (i.e. polling a lot of repos, most of them did *not* change, by build bots which are really eager to try again after a minute). That is why we use a superproject, with all other repositories as a submodule for polling, as that would slash the ls-remote traffic approximately by the number of repositories. There was an attempt in JGit to support this type of communication of long polling at https://git.eclipse.org/r/plugins/gitiles/jgit/jgit/+/2adc572628f9382ace5fbd791325dc64f7c968d3 but not a whole lot is left over in JGit as it was refactored at least once again. IIRC the issues where in the lack of protocol definition that made it usable for a wider audience.
