Re: [PATCH 1/1] fetch: add fetch.writeCommitGraph config setting

From: Derrick Stolee <stolee@gmail.com>
Date: Sep 6, 2019, 21:04 UTC
Message-ID: <25ed1562-dc74-1ebc-46ff-d6cd643504a4@gmail.com>
In-Reply-To: <xmqqpnkdma0g.fsf@gitster-ct.c.googlers.com>

On 9/6/2019 4:42 PM, Junio C Hamano wrote:

Show 13 quoted lines

> Jeff King <peff@peff.net> writes:
> 
>> I suppose so. But I think the "stock git without any other job
>> infrastructure" case would still benefit.
> 
> Oh, no question about it.
> 
> I did question if an automatic writing would benefit the side that
> receives a push when you brought up the usual "fetch.* and receive.*
> for separate configuration, transfer.* when want to rule them both"
> convention, which is a good idea if only for consistency, but the
> question was if it helps the receiving end of a push to the same
> degree as it would help the repository that fetches.

I think the "stock git without any other job infrastructure" is a very important scenario. Putting the simplest version of "commit-graph writes in-line with every push" seems to be ripe for failure under load. I'd rather think deeply about what is best for this scenario.

Spit-balling: what if we used the same mechanism as running GC
in the background to launch 'git commit-graph write' commands?
And we could have the command give up (without failure) if the
commit-graph.lock file is already created, so concurrent pushes
would not fight each other.

Thanks, -Stolee