Re: upload-pack is slow with lots of refs

On Wed, Oct 3, 2012 at 7:36 PM, Ævar Arnfjörð Bjarmason
[off-list ref] wrote:

I'm creating a system where a lot of remotes constantly fetch from a
central repository for deployment purposes, but I've noticed that even
with a remote.$name.fetch configuration to only get certain refs a
"git fetch" will still call git-upload pack which will provide a list
of all references.

This is being done against a repository with tens of thousands of refs
(it has a tag for each deployment), so it ends up burning a lot of CPU
time on the uploader/receiver side.

If all refs are packed, will it still burn lots of CPU on server side?

Has there been any work on extending the protocol so that the client
tells the server what refs it's interested in?

It'll be a new protocol, not an extension for git protocol. Ref
advertising is step 1. Capababilities are advertised much later. The
client has to time to tell the server what protocol version it likes
to use for step 1. (I looked at this protcol extension from a
different angle. I wanted to compress the ref list for git protocol.
But git over http compresses well so I don't care much.)

On that git-over-http, I don't know, maybe git client can send
something as http headers, which are recognized by the server end, to
negotiate interested ref patterns?
-- 
Duy