On Sat, Jul 11, 2015 at 12:00 AM, Ilari Liusvaara <ilari.liusvaara@xxxxxxxxxxx> wrote: > On Sat, Jul 11, 2015 at 11:10:48AM +0800, ForceCharlie wrote: >> As we known, HTTP/2.0 has been released. All Git-Smart-HTTP are currently >> implemented using HTTP/1.1. > > Nit: It is HTTP/2. > >> Frequently used Git developers often feel Git HTTP protocol is not >> satisfactory, slow and unstable.This is because the HTTP protocol itself >> decides > > Note that there are already two versions of HTTP transport, the old "dumb" > one and the newer "smart" one. > > The smart one is difficult to speed up (due to nature of the negotiations), > but usually is pretty reliable (the efficiency isn't horrible). The negotiation in smart-HTTP actually has some bad corner cases. Each round of negotiation requires a new POST resupplying all previously agreed upon SHA-1s, and a batch of new SHA-1s. We have observed many rounds where this POST is MiBs in size because the peers can't quite agree and have to keep digging through history. The native protocol on git:// and SSH is not as bad. Negotiation is still many rounds, but these are pipelined and each round does not need to repeat the prior round, as the server has a single stream and is saving state. > Now, the old "dumb" protocol is pretty unreliable and slow. HTTP/2 probably > can't do anything with the reliability problems, but probably could improve > the speed a bit. > > Websockets over HTTP/2 (a.k.a. "websockets2") has not been defined yet. > With Websockets(1), it would probably already be possible to tunnel the > native git smart transport protocol over it. Probably not worth it. Another option is to tunnel using gRPC (grpc.io). libcurl probably can't do this. And linking grpc.io library into git-core is crazy. So its probably a non-starter. But food for thought. But, at $DAY_JOB we tunnel the native bidirectional protocol in grpc.io's predecessor, and it works quite well for us. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html