RE: reftable [v5]: new ref storage format
- Date: Mon, 7 Aug 2017 15:40:48 +0000
- From: David Turner <David.Turner@xxxxxxxxxxxx>
- Subject: RE: reftable [v5]: new ref storage format
> -----Original Message-----
> From: Shawn Pearce [mailto:spearce@xxxxxxxxxxx]
> In git-core, I'm worried about the caveats related to locking. Git tries to work
> nicely on NFS, and it seems LMDB wouldn't. Git also runs fine on a read-only
> filesystem, and LMDB gets a little weird about that. Finally, Git doesn't have
> nearly the risks LMDB has about a crashed reader or writer locking out future
> operations until the locks have been resolved. This is especially true with shared
> user repositories, where another user might setup and own the semaphore.
FWIW, git has problems with stale lock file in the event of a crash (refs/foo.lock
might still exist, and git does nothing to clean it up).
In my testing (which involved a *lot* of crashing), I never once had to clean up a
stale LMDB lock. That said, I didn't test on a RO filesystem.