Clusters and Grid Computing
June 12, 2007 by Bryce Edwards, Technology in Tech Stuff
I live and breathe technology, just like many of our customers. In speaking with my colleagues, they encouraged me to share my thoughts on a few technologies that are important to the Web hosting business.
In particular, clustering is top of mind for me right now. We talk a lot about clustering. So what does it really mean? Clustering involves multiple computers working together so they can be viewed as one. You’ve probably heard of a database cluster or a clustered Web server farm. These are prime examples of taking multiple servers and using clustering to give you high availability or high-performance computing which provides scalability that’s typically achieved by load balancing servers within the cluster.
One thing common with clusters is that the servers are typically setup independently and then joined with the cluster. This means that the operating system and applications are installed, and then configured to work as part of the cluster. For most clustering implementations, a single application instance cannot use the resources of more than one physical machine.
If you want an application to run on three servers, it requires that you install the application on three nodes in a cluster. Then the cluster can be set-up for load balancing the application across the three nodes.
Another critical clustering factor that shouldn’t be overlooked is storage. Clusters typically share a common back-end storage system so that all nodes in the cluster are working with the same data. Whether it’s a SAN with Web application content with all the nodes performing simultaneous reads in a load balancing cluster, or a direct attached storage subsystem that the nodes of a high-availability cluster exclusively access, the common shared storage is an integral part. For example, products may include Oracle Real Application Cluster (RAC), Microsoft Windows Compute Cluster Server, Sun Cluster and RedHat Cluster Suite.
Another hot topic is grid computing, which has many similarities to clusters and is often referred to interchangeably. A grid offers the ability to add or remove resources — like servers — from the grid as needed. This is referred to as “computing on demand” or “cloud computing.”
One distinction is that applications on a grid can typically scale to more than one physical server. Another nice feature of grid computing is that each node can be commodity hardware, so we can leverage the servers we already offer which provides a value to both our customers and to The Planet.
A grid is also well suited for running separate applications in a utility computing environment. Imagine if you had a SaaS application, and it ran on a grid where you subscribed to a minimum set of resources like CPU GHz, storage GBs and network Mb/sec. The grid would dedicate the minimum required resources to your application, and make sure there are enough resources in reserve to meet any bursting or scaling that may be required. It could add more servers to your grid on demand and free them up when they are no longer needed.
So these are the type of technologies that we’re evaluating at The Planet. Stay tuned for more details.
- Bryce
June 29th, 2007 at 7:58 am
I just reviewed a solution from 3Tera. Their AppLogic platform was very impressive. We managed a number of private rack clients at ThePlanet (EV1). The AppLogic platform would greatly simplify our deployments, allow us to architect solutions quickly on commodity hardware. When we need to grow, we just add more nodes to the grid. These nodes could be your stock boxes, so you can quickly deploy them.
I will be very interested to see what grid technologies you guys roll out.
July 26th, 2007 at 4:09 pm
[...] Bryce Edwards, who’s on The Planet team, explained the basics of clusters and Grid Computing about a month and a half ago, but I hope that you will accept my toonie on the topic (because two Canadian dollars are worth just a bit more than two cents here in the US). [...]