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Subject: Re: Aamzon EC2 & Cassandra to ebs or not..
From: Jeremy Hanna <jeremy.hanna1234@gmail.com>
In-Reply-To: <AANLkTimB+Jd+qViA2N_3Yy1m=wFHn1wCX4PizKwOVzkx@mail.gmail.com>
Date: Wed, 9 Mar 2011 10:24:22 -0600
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To: user@cassandra.apache.org

I've seen both sides but Cassandra does handle replication and bringing =
data back is a matter of bootstrapping a node to replace the downed =
node. =20

One thing to consider is availability zones and regions though.  What =
happens if your entire cluster goes down in the case of a single =
datacenter going offline?  =46rom what I understand ec2 availability =
zones are equivalent to physical datacenters so going across =
availability zones will handle an entire datacenter going down.  Regions =
are another level of safeguarding against this.  Anyway, just some =
thoughts.

Some considerations are also found in the Cloud section of this page: =
http://wiki.apache.org/cassandra/CassandraHardware

On Mar 9, 2011, at 9:57 AM, Sasha Dolgy wrote:

>=20
> well, this is what i'm getting at.  why would you want to back it up =
if the cluster is working properly?  backup is silly.... ; )
>=20
> On Wed, Mar 9, 2011 at 4:54 PM, William Oberman =
<oberman@civicscience.com> wrote:
> I'm considering similar issues right now.  The problem with ephemeral =
storage is I don't know an easy way to back it up, while on an EBS it's =
a simple snapshot API call.
>=20
> Otherwise, I believe the performance of the ephemeral (certainly in =
the case of large or greater, where you can RAID0 multiple disks) is way =
better than EBS.
>=20
> will
>=20