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 <ober...@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
