MongoDB on EC2 Best Practices

In light of last week’s EBS issues, we wanted to make sure MongoDB users on EBS are configured to be as robust as possible. A basic setup would consist of a 3 node replica set. The nodes would be roughly laid out like this: * A: us-east-1a priority 1 * B: us-east-1b priority 1 * C: us-west-1a priority 0

During steady state, either A or B would be primary. If the primary went down for any reason (system crash, or loss of one availability zone) the other node in us-east would take over. This is guaranteed because the west coast node has a priority of 0. If instead the entire east coast region were lost, then you would still have a ful copy of data on C. If you decided that you were going to make the west coast your primary data center for the duration, you would just bring up a couple more nodes there, and make a new replica set with the data from C. More information about running MongoDB on ec2 is available from our recent ec2 webinar. We are big fans of cloud computing in general and want MongoDB to only get more and more cloud-friendly over time. -Eliot