Re: git receive-pack deletes refs one at a time?

[Nasser Grainawi <nasser@codeaurora.org>]

> On Jun 13, 2019, at 11:43 AM, Jeff King <peff@peff.net> wrote:
> 
> On Thu, Jun 13, 2019 at 11:33:40AM -0600, Nasser Grainawi wrote:
> 
>> I have a situation where I need to delete 100k+ refs on 15+ separate
>> hosts/disks. This setup is using Gerrit replication, so I can trigger
>> it all on one host and it will push the deletes to the rest (all
>> running git-daemon v2.18.0 with receive-pack enabled). All the refs
>> being deleted on the receiving ends are packed.
>> 
>> What I see is the packed-refs file getting locked/updated over and
>> over for each ref. I had assumed it would do something more like
>> 'update-ref --stdin' and do a bulk removal of refs. Am I seeing the
>> correct behavior? If yes, is there a specific reason it works this way
>> or is "bulk delete through push" just a feature that hasn't been
>> implemented yet?
> 
> The underlying ref code is smart enough to coalesce all of the deletions
> in a single transaction into a single write of the packed-refs file.
> 
> But historically, pushes do not do a single ref transaction because we
> would allow the push for one ref to succeed while others failed. Later,
> we added an "atomic" mode that does it all in a single transaction.
> 
> Try with "git push --atomic", which should be able to do it in a single
> write.

Thanks!

Is there a way to get the bulk behavior without the all-or-nothing behavior?

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