Linux containers, docker, SSD, and RAID.

[Kevin Burton <bu...@spinn3r.com>]

Hey guys.

Question about using container with Cassandra.

I think we will eventually deploy on containers… lxc with docker probably.

Our first config will have one cassandra daemon per box.

Of course there are issues here.  Larger per VM heap means more GC time and
potential stop the world and latency issues.  And we also have to run SSD
on RAID which is no fun.

So I think what we're planning on doing is running with 32-64GB boxes, with
8-16GB of memory per container.

If we have 4x SSDs on a box, then we can have each container have its own
SSD, it's own memory, etc.

One issue is the data placement.  Obviously we don't want to put all the
data on the same box… so I was thinking of telling it that each lxc is on
the same rack.

Right now there's data centers , and racks, which you have to focus on in
terms of replica placement.

But now there's one additional level… host.

So I was thinking we could just have rack IDs be rack.host… or rack_host.
 This way cassandra knows not to place a replica on the same host but just
in a different container.

Thoughts?

-- 

Founder/CEO Spinn3r.com
Location: *San Francisco, CA*
Skype: *burtonator*
blog: http://burtonator.wordpress.com
… or check out my Google+ profile
<https://plus.google.com/102718274791889610666/posts>
<http://spinn3r.com>
War is peace. Freedom is slavery. Ignorance is strength. Corporations are
people.