First Stop to Cassandra

So I start my search for a non relational database one more time to see if the latest buzz about NoSQL really worth it or is it just another time when we are looking at the options which eventually are going to die down for the ever dominant RDBMS.

I soon realized NoSQL encompasses much more then I would liked (just because I find myself a little lost with so many options) with so much already out there challenging the SQL databases. My first stop Cassandra.

Why Cassandra? – For me at least to start with the need for a non RDBMS has been quite straight forward, a data store which can provide me high availability with complete fault tolerance, highly scalable, very minimal downtime if any. This is mostly achieved through highly replicated and db clustered environment. Cassandra comes out as a natural choice to explore.

Application Availability

Availability should be defined not just at the application level scope but also at each functionality level. It should be further quantified in terms of acceptable response time.

Availability of an application is increased by getting rid of single point of failure and this is done by converting this point into a pool of points so that if one goes down, the request is served by another point. Pooling the point is more commonly referred as horizontal scaling and building for it requires load balancing the requests hitting the application plus a provision for fail over support.

Load balancing and fail over support is done through deploying the application in a clustered environment. Clustering not only ensures high availability but also make the application more scalable. Clustering is the term which describes the was to provide redundant servers to ensure high availability.

Clustering is OK but what to cluster, anything where we are calling a distributed object, so need to cluster those components that can be deployed in a distributed way.