On Thu, Dec 24, 2020 at 12:40:54AM +0000, Roy Marples wrote:
I've decided that I'm done for now with analyzing the clone performance
for now. There are a few delays still in the process due to a
combination of the unusual history and somewhat high IO latency, but
they should no longer break anything and would disappear with a new
clonebundle.
So aside from getting Mercurial to perform better for us given our
repository, what are the show stoppers for actually moving it to production
and retiring CVS?
So the one big question that remains for me is whether we are willing to
do a second hg->hg migration at some point in the not so far future.
There are at least two big reasons for that, both breaking the hash
chain:
(1) "Bonsai" changesets
(2) SHA1 replacement
The former is a pretty significant change in the data model under some
discussion at the moment. It would address some of the big remaining
blocks in the clone time and also other topics. The latter should be
self-explanatory. The user impact of both is primarily the hash break.
It should be possible to fix up references in the commit messages
automatically, but if they leak into files that would be more tricky.