If possible, it would be much better to make it pluggable so that we select what we want. On Tue, May 3, 2016 at 6:25 AM, Wido den Hollander <wido@xxxxxxxx> wrote: > >> Op 2 mei 2016 om 20:49 schreef Sage Weil <sweil@xxxxxxxxxx>: >> >> >> We're thinking about switching the default backend on the mon from leveldb >> to rocksdb. Rocksdb is better maintained, has a stronger feature set, is >> generally faster, and is linked statically, which means we won't be >> vulnerable to buggy distro packages. >> >> There is one blocker, though. Some distro leveldbs name the sst files >> with the .ldb suffix. (Some don't; very annoying.) There is a unit test >> in rocksdb that tries to verify that ldb is silently renamed to sst, >> and it passes, but the test is incomplete: the test failes to verify >> that ldb/sst files can actually be read, and it turns out only the 'check' >> path (not the normal open and read it path) handles ldb properly. >> >> Anyway, once that works, rocksdb will magically upgrade from leveldb to >> rocksdb. Note that once that happens you can't switch from rocksdb back >> to leveldb without recreating the mon. >> >> Alternatively, we could not worry about upgrading existing leveldb >> instances and just make newly created mons default to rocksdb. >> >> 1) Thoughts on moving to rocksdb in general? >> >> 2) Importance of leveldb->rocksdb conversion? >> > > I would not touch this auto conversion at first. I know there is things to gain, but is it enough to gain that it might be worth while potentially corrupting monitors? > > Is it that LevelDB doesn't handle large cluster load for example? Imho the majority of Ceph clusters is still far below 500 OSDs. > > Personally I always try to stay away from touching the MONs datastore. Always feels a bit scary. > > Wido > >> 3) Anyone want to fix the ldb handling in rocksdb? >> >> Thanks! >> sage >> >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Email: shinobu@xxxxxxxxx GitHub: shinobu-x Blog: Life with Distributed Computational System based on OpenSource -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
