Tricks for taming large repo manifests and/or improving large repo clone times?

[Pierre-Yves David]

On 5/29/19 12:28 PM, Lawrence Stewart wrote:
> Greetings all,
> 
> I maintain unofficial Mercurial seed repos [1] for the FreeBSD project's
> Subversion base system [2] and ports (non-base-system software) [3]
> repositories. They have sizable code bases and 20+ year development
> histories with quite a few active branches, and I'm curious if there are
> any tricks to make first-time cloning operations non-glacial?
> 
> The server-side repos have been re-cloned in place to bring them up to
> the latest on-disk format as of mercurial 4.9 so they've got
> generaldelta and sparserevlog enabled, yet the manifest remains a beast
> (see end of email for some stats). A git clone from Github [4] is on the
> order of 1.5GiB and substantially faster to clone.

Manifest size issues I have met in the past are usually tackled through 
the use of sparse-revlog. However, you might need to force a delta 
recomputation to get the full benefit. You can do it using the following 
command:

   $ hg debugupgraderepo --optimize re-delta-all --run

(this will take a while)

A bit more details:

Looking at The statistic you pasted, I see 12222 delta against "others", 
while you only have 249 snapshots. So I suspect your in-place pull 
inherited bad delta that the previous format generated. The command 
above should fix that by forcing these deltas to be recomputed toward a 
better base.

> Am I missing anything obvious that would improve the situation?

I am getting a local clone of your repo to have a look at it. I will 
keep you posted.

Cheers,

-- 
Pierre-Yves David