couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Metin Akat <akat.me...@gmail.com>
Subject Re: Which filesystem is best for deploying couchdb and why?
Date Sat, 18 Sep 2010 07:49:22 GMT
What part of this blog post is relevant to btrfs?

On Fri, Sep 17, 2010 at 10:22 PM, Chris Anderson <jchris@apache.org> wrote:
> On Thu, Sep 16, 2010 at 6:22 PM, Tyler Gillies <tyler@pdxbrain.com> wrote:
>> Wow, thanks for the thought out writeup!
>>
>
> here's a blog post http://letsgetdugg.com/2010/06/25/couchdb-on-zfs/
>
>> On Thu, Sep 16, 2010 at 12:47 PM, Randall Leeds <randall.leeds@gmail.com>wrote:
>>
>>> Disclaimer: I'm no file systems expert.
>>>
>>> I recommend something with extents otherwise you might take a big
>>> performance hit while couch deletes old db files after compaction.
>>> Compression sounds cool as long as you can do it really fast (are
>>> there setups where this happens in hardware?).
>>>
>>> reiserfs:
>>> According to wikipedia it "still uses the big kernel lock (BKL) — a
>>> global kernel-wide lock" which makes performance on multiple cores
>>> suffer.
>>> It's big benefit, as I always understood it, is being able to pack
>>> smile files together into single blocks. You will likely not have lots
>>> of small files with Couch :-P
>>>
>>> xfs:
>>> Delayed allocation might be a big performance win with a Couch. Since
>>> outstanding writes are committed together in chunks and then fsync'd
>>> all together I bet this feature would do good things for Couch
>>> performance.
>>>
>>> ext(3|4)
>>> I'd recommend ext4 over ext3. Delayed allocation like xfs as well as
>>> the multiblock allocator should make it much better than ext3. You
>>> also get extents.
>>>
>>> btrfs/zfs:
>>> Some of the features of each sound interesting, but nothing that
>>> stands out to me as "great for CouchDB". Snapshots and backups are
>>> cool, but Couch is doing this for you already in a sense due to the
>>> way the btree is appended: CouchDB documents are, in a sense,
>>> copy-on-write. Checksumming is cool if you think it's important for
>>> your data integrity. If you want snapshots for backup you can always
>>> use CouchDB replication.
>>>
>>> If you run any tests I'd be very, very interested in seeing your results.
>>>
>>> -Randall
>>>
>>> On Thu, Sep 16, 2010 at 03:11, Metin Akat <akat.metin@gmail.com> wrote:
>>> > I'm sure almost everybody out there is using ext4/3 (including me),
>>> > but what about filesystems like btrfs, zfs, reiserfs, xfs. Some of
>>> > them have very appealing feature-sets (like compression for example,
>>> > and we all know how greedy is couchdb for disk space).
>>> > And I know that for example btrfs is not yet "recommended for
>>> > production". But its time is coming. From what I see, Ubuntu 10.10
>>> > works flawlessly on btrfs.
>>> > So I'd be happy if we have some discussion on the topic, instead of
>>> > "everybody uses ext4, just use it" kind of stuff :).
>>> > Couchdb was "alpha software" for years, and we all used it in
>>> > production, so we are not afraid of alpha/beta software, as long as
>>> > it's good :)
>>>
>>
>>
>>
>> --
>> http://www.readwriteweb.com/about#tyler
>>
>> Ask me anything <http://tumble.pdxbrain.com/ask>!
>>
>
>
>
> --
> Chris Anderson
> http://jchrisa.net
> http://couch.io
>

Mime
View raw message