On 2013-08-27, at 6:04 AM, Aklin_81 <asdk...@gmail.com> wrote:
> For any website just starting out, the load initially is minimal & grows with > a slow pace initially. People usually start with their MySQL based sites > with a single server(***that too a VPS not a dedicated server) running as > both app server as well as DB server & usually get too far with this setup & > only as they feel the need they separate the DB from the app server giving it > a separate VPS server. This is what a start up expects the things to be while > planning about resources procurement. > > But so far what I have seen, it's something very different with Cassandra. > People usually recommend starting out with atleast a 3 node cluster, (on > dedicated servers) with lots & lots of RAM. 4GB or 8GB RAM is what they > suggest to start with. So is it that Cassandra requires more hardware > resources in comparison to MySQL, for a website to deliver similar > performance, serve similar load/ traffic & same amount of data. I understand > about higher storage requirements of Cassandra due to replication but what > about other hardware resources ? > > Can't we start off with Cassandra based apps just like MySQL. Starting with 1 > or 2 VPS & adding more whenever there's a need. Renting out dedicated servers > with lots of RAM just from the beginning may be viable for very well funded > startups but not for all. Yes you can, just make sure you do your homework, evaluate and measure things. MySQL is a row-oriented RDBMS. Cassandra is a distributed columnar key-value store. While both are "databases", they serve different use cases. I think it's an illusion that a startup can "get by" on just a single virtual instance somewhere. It's certainly doable, but very risky Doing that means that if the server catches on fire, your startup's data and other IP is lost. Any reasonable architecture in this day and age must account for such disasters. Cassandra is built around failure-is-a-norm, and this is handled by encouraging multiple servers and increased replication factor as a default. You can certainly scale that back down to a single-machine if you want, provided you understand what risks you're taking. Performance-wise, cassandra's quite fast even in a single-node scenario. Again, take that at face value and do your own benchmarks using your use cases and workloads.
