Like all other start-ups, we too cannot start with all dedicated servers for Cassandra. So right now we have no better choice except for using a VPS :), but we can definitely choose one from amongst a suitable set of VPS configurations. As of now since we are starting out, could we initiate our cluster with 2 nodes(RF=2), (KVM, 2GB ram, 2 cores, 30GB SDD) . Right now we wont we having a very heavy load on Cassandra until a next few months till we grow our user base. So, this choice is mainly based on the pricing vs configuration as well as digital ocean's good reputation in the community.

On Sun, Aug 4, 2013 at 12:53 AM, David Schairer <dschairer@humbaba.net> wrote:
I've run several lab configurations on linodes; I wouldn't run cassandra on any shared virtual platform for large-scale production, just because your IO performance is going to be really hard to predict.  Lots of people do, though -- depends on your cassandra loads and how consistent you need to have performance be, as well as how much of your working set will fit into memory.  Remember that linode significantly oversells their CPU as well.

The release version of KVM, at least as of a few months ago, still doesn't support TRIM on SSD; that, plus the fact that you don't know how others will use SSDs or if their file systems will keep the SSDs healthy, means that SSD performance on KVM is going to be highly unpredictable.  I have not tested digitalocean, but I did test several other KVM+SSD shared-tenant hosting providers aggressively for cassandra a couple months ago; they all failed badly.

Your mileage will vary considerably based on what you need out of cassandra, what your data patterns look like, and how you configure your system.  That said, I would use xen before KVM for high-performance IO.

I have not run Cassandra in any volume on Amazon -- lots of folks have, and may have recommendations (including SSD) there for where it falls on the price/performance curve.


On Aug 3, 2013, at 11:33 AM, Ertio Lew <ertiop93@gmail.com> wrote:

> I am building a cluster(initially starting with a 2-3 nodes cluster). I have came across two seemingly good options for hosting, Linode & Digital Ocean. VPS configuration for both listed below:
> Linode:-
> ------------------
> XEN Virtualization
> 2 GB RAM
> 8 cores CPU (2x priority) (8 processor Xen instances)
> 96 GB Storage
> Digital Ocean:-
> -------------------------
> KVM Virtualization
> 2GB Memory
> 2 Cores
> 40GB **SSD Disk***
> Digitial Ocean's VPS is at half price of above listed Linode VPS,
> Could you clarify which of these two VPS would be better as Cassandra nodes ?