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What I'd love is for the L2ARC system built on top of ZFS to be ported as well. That's a killer feature for web applications. Basically, it can extend your cach
by binomial 16y ago
What I'd love is for the L2ARC system built on top of ZFS to be ported as well. That's a killer feature for web applications. Basically, it can extend your cache to include an SSD, but manage that all internally, so you just use your database as usual on top of ZFS and let it handle all the caching and moving less used data from SSD to disk and vice versa, and of course the usual filesystem caching in RAM as well.
Though you could get similar functionality by using membase at the expense of being limited to get/set operations (it's a K/V store).
- ssmoot 16y agoIf it's as small as a single server, you probably don't need an SSD to cache access. If your db server is partitioned out, just put the whole fs on SSD. You can't partition the L2ARC, so you really don't want to mix web assets with database volumes. The assets will push your db out of the cache unless it's so big that you're massively overpowered, or traffic so low it didn't matter in the first place. That's some hard won knowledge there. :-) (You can choose to cache assets meta-data only, but that tuning has major downsides itself and while it may protect your db, it's also likely to render your caches very under-utilized. Basically it isn't a silver bullet and it's still important to think of volumes and work-loads in terms of what "spindles" they're on.
- kmavm 16y agoSee Facebook's FlashCache if you get tired of waiting: http://www.facebook.com/note.php?note_id=388112370932 http://www.facebook.com/note.php?note_id=388112370932