Any new application implementation will further add to this complexity. Looking to utilise existing spare computing capacity is near impossible. When an application usage is expanded beyond planned capacity or when there are unanticipated loading spikes, it is not possible to quickly scale the application to support the spikes and peaks. Most enterprise applications ended up over provisioning to handle these occasional spikes in load.

Traditional Application Silo Architecture which constrict applications to their dedicated resources.

Enterprise Application Virtualisation is an emerging trend for application deployment in enterprises today. Some vendors would call it application centric compute resource provisioning.

Enterprise Application Virtualisation essentially decouples an application from its underlying infrastructure components like the Operating System, memory, storage and network. The application being infrastructure independent can then be dynamically deployed based on load and system environment.

So what benefits does Enterprise Application Virtualisation bring?

Enterprise Application Virtualisation Architecture allows for dynamic allocation of compute resources base on application’s real time needs.

Lower Cost
There will be a lower total cost of ownership for applications that are virtualised in contrast to traditional deployments. With application virtualisation, higher resource utilisation can be realized. This will allow for server consolidation and with it, the corresponding savings.

Speed of Deployment
When a virtualised application is deployed into a shared virtual infrastructure, it can take advantage of the existing configurations for network and security which was set up previously. This will reduce the time needed in application deployment. With the improved time to market, enterprises will be able to better respond to the market and allow for a higher rate in return of IT investments.

Performance
Application performance can be improved with the dynamic allocation of computing resources. The virtualized infrastructure reacts accordingly to the real time application needs and the provisioning policies that were defined beforehand. Service Level Agreements can be improved to benefit end users.

Scalability
Installation of additional server can be done without disruption to existing operations. This is because the application is decoupled from its underlying infrastructure. Once setup and configured, an additional server can be registered with the virtualisation middleware to be made available for application usage.

High Availability
As some virtualisation middleware enables a stateful transition of application, High Availability and Disaster Recovery can be achieved without loss of transient user data or major disruptions to the end user experience.

An enterprise application virtualisation middleware is key to such an infrastructure. It will be responsible to dynamically distribute compute resources in real time to applications based on its load conditions. Enterprise application virtualisation middleware is available today. Examples of which are Platform Enterprise Grid Orchestrator (EGO), VMWare Infrastructure, United Devices Data Center One and DataSynapse FabricServer.

Challenges
Although the benefits of virtualisation are clear, enterprises still have some challenges to overcome.

The reliability of any virtualised environment for mission critical systems needs to be ascertained clearly before adoption. There is a mix of success and horror stories shared by early adopters. Most successful implementations have been on an incremental approach rather than a big bang.

Third party software licensing scheme poses another major stumbling block to Enterprise Application Virtualisation adoption. Most software vendors have not been actively looking at licensing models to suit a virtualized infrastructure. Although virtualized middleware can provide for usage metering and policy management to control the extend of scalability, both enterprises and vendors would very much prefer a fix rate license charging model due to the ease and clarity of financial accounting. However, with the strong push towards Virtualisation, market competition and the availability of alternative free open-source software, software vendors are likely to introduce licensing models based on virtualized infrastructure very soon.

The Way Ahead
Enterprise Application Virtualisation offers enterprises an option to harness the benefits of IT without its associated high cost and inflexibility. This is a significant step forward especially for the Small and Medium Enterprises looking at improving competitiveness through the effective use of IT in their business.

Enterprise Application Virtualisation calls for a shared infrastructure which can be extended beyond a single enterprise boundary to serve multiple enterprises concurrently. With the virtualisation middleware technologies available today, it is possible to setup such a cross-enterprise environment which will further lower the infrastructure costs through economy of scale.

Contributed by Mr Lee Boon Seng, Consultant, Technology Directions, IDA.