Adding Cross Zone Load Balancing in AWS

One of the new hotness features that Amazon added to their Elastic Load Balancers is cross zone load balancing. This offers the ability to have an unbalanced number of nodes per availability zone within an Amazon region. For instance, if you were load balances across us-east-1a, us-east-1b, and us-east-1c, then you needed to have the same number of instances in each zone otherwise the traffic would skew and overload the zone with fewer instances. If you are auto-scaling, using spots, or just happen to lose instances from time to time, you can easily see where this becomes a problem. Read the rest of this entry »

Redis Setup Notes and One-Liners

Being a heavy user of Redis has forced some weird Bash-fu and other commands when I want to find out how things are going. Because Redis is single threaded (see here for more information), I commonly run multiple Redis instances per machine. As a result, when running on AWS, I use a specific machine layout to get the best CPU utilization for Redis. On an m2.4xlarge machine, it comes with 8 cores and 68G of RAM. To take full advantage of that I run 7 instances of Redis and pin one instance to a CPU core (this can be done using taskset in schedutils package). For extra performance, I leave an entire core to the OS (even though the machines do little other than process Redis commands. Read the rest of this entry »

Cassandra Summit 2012 Highlights

I was lucky enough to have the opportunity to speak at the Cassandra World Summit 2012 on August 8 in Santa Clara. It was an amazing opportunity to share with the community the types of things that SimpleReach does with Cassandra. Not only that, I learned a lot about the roadmap and got to put a bunch of faces with the names behind the project.
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What’s So Great About Cassandra’s Composite Columns?

There are a lot of things I really like about Cassandra. But one thing in particular I like in creating a schema is having access to composite columns (read about composite columns and their origins here on Datastax’s blog). Let’s start simple with explaining a composite columns and then we can dive right into why they are so much fun to work with.
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