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From Sasha Dolgy <sdo...@gmail.com>
Subject Re: advice for EC2 deployment
Date Wed, 27 Apr 2011 13:21:31 GMT
Hi William,

The default behavior of Ec2Snitch is outlined below:

http://svn.apache.org/repos/asf/cassandra/trunk/src/java/org/apache/cassandra/locator/Ec2Snitch.java

        // Split "us-east-1a" or "asia-1a" into "us-east"/"1a" and "asia"/"1a".
        String azone = new String(b ,"UTF-8");
        String[] splits = azone.split("-");
        ec2zone = splits[splits.length - 1];
        ec2region = splits.length < 3 ? splits[0] : splits[0]+"-"+splits[1];
        logger.info("EC2Snitch using region: " + ec2region + ", zone:
" + ec2zone + ".");

ApplicationState.DC = ec2region
ApplicationState.RACK = ec2zone

We leverage cassandra instances in APAC, US & Europe ... so it's
important for us to know that we have one data center in each 'region'
and multiple racks per DC ...

-sasha

On Wed, Apr 27, 2011 at 3:06 PM, William Oberman
<oberman@civicscience.com> wrote:
> It's great advice, but I'm still torn.  I've never done multi-region work
> before, and I'd prefer to wait for 0.8 with built-in inter-node security,
> but I'm otherwise ready to roll (and need to roll) cassandra out sooner than
> that.
>
> Given how well my system held up with a total single AZ failure, I'm really
> leaning on starting by treating AZ's as DCs, and racks as... random?  I
> don't think that part matters.  My question for today is to just use the
> property file snitch, or to roll my own version of Ec2Snith that does AZ as
> DC.
>
> I do increase my risk being single region to start, so I was going to figure
> out how to push snapshots to S3.  One question on that note: is it better to
> try and snapshot all nodes at roughly the same point in time, or is it
> better to do "rolling snapshots"?
>
> will

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