Most of the buzz and appeal around cloud computing revolves around the notion of “instant scalability.” This buzz is justified due to the unbelievable functionalities of Cloud Computing infrastructure itself; however, what is often failed to be considered when discussing Cloud Computing is how to achieve true "application scalability"... which is much different that the discussion regarding scaling Cloud infrastructure.
Cloud vendors that provide only single instance management (think, AMI's on Amazon EC2) are short-changing the true benefits of Cloud computing related enterprise-level application scaling. Most enterprise-level applications are architected in multi-tier, multi-server (web, app, DB) configuration; making a Cloud solution consisting of a single "machine image" largely irrelevant.
When choosing a Cloud platform to deploy your applications upon, you must understand how your choice of Cloud vendor may affect your success in the Cloud. To demonstrate the importance of choosing the correct Cloud environment to meet your scalability requirements, we have provided an example using ESRI® ArcGIS Server, deployed in a multi-tiered configuration, on two different Cloud infrastructures: Amazon EC2 and the AppLogic-based Skygone Cloud.
If you are unfamiliar with the AppLogic platform, take note that AppLogic was the very first Cloud platform to hit the IT market (Feb 2006), about 6 months before Amazon EC2 Beta was released (Aug 2006). Also a recent Forrester® Research, Inc. study named AppLogic by 3Tera® “The leading Cloud infrastructure software.”
AppLogic allows for complex applications, like ArcGIS Server, to be templated in a multi-tier configuration and managed as a single object (see graphic below). It also enables a single point for in-bound http traffic to multi-tier application webservers through a single gateway; allowing you to more easily secure and manage the IP addressing of the multi-tier application. Meaning, not only are additional virtual servers in the Web or Application tier automatically started based on increased user load, but AppLogic also automatically connects those new servers to the already functioning application... no IP addresses configure. It simply scales.
By the way, this all happens without application code changes and without the advanced scripting, which is usually required to create scalable multi-tier applications in Cloud environments are managed as single virtual machine images.
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Tuesday, August 31, 2010 at 11:52AM 