Gartner research has shown that in recent years there has been a shift in demand from simple server load balancing devices to more advanced solutions with a richer feature set, increased functionality and greater focus on effective application delivery. This shift is borne from a need to improve the performance, reliability and manageability of application delivery platforms and SOA’s. Gartner states: “The era of load balancing is long past, and organizations will be better served to focus their attention on improving the delivery of applications.” *
Enter the ADC
“ADCs provide a set of functions to optimize enterprise application environments. The market evolved from the load-balancing systems that were specifically developed to ensure the availability and scalability of websites. Enterprises use ADCs to optimize reliability, end-user performance, data center resource use and security for a variety of enterprise applications.” Gartner.
The below diagram maps forecasted Application Delivery Controller End-User Spending, Worldwide, 2005-2010.
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ADCs are designed for data centre applications and improve the performance of Web-based and related applications by providing a suite of services at the network and application layers. Advanced ADC’s become actively involved in the delivery of the application and provide sophisticated capabilities as opposed to Server load balancing solutions that typically perform a basic set of functions, including load balancing, basic health checks and Secure Sockets Layer (SSL) offload processing.
Advanced platform ADCs provide the basic Server Load Balancing functionality and additionally provide support for real-time protocol manipulation (for example, Transmission Control Protocol [TCP] connection management and HTML optimization), data compression, network address translation, traffic shaping, quality of service (QOS), DOS protection, SSL Offload and resiliency/failover. These devices are being enhanced by the addition of new protocol intelligence and new services, such as content transformation and transaction assurance.
Advanced ADC Features
According to Gartner, the following features define an advanced ADC:
jetNEXUS technology belongs to the advanced platform ADC group
Gartner predicts that customers will be upgrading to the advanced platform ADCs in preference to the older generation SLBs. Customers will strive to simplify their infrastructures yet achieve higher performance and better management of their application traffic.
Older generation SLBs (Cisco CSS, Nortel/Alteon, Radware WSD, Foundry, Coyote Point, Kemp, etc.) do not provide any benefits of acceleration from TCP offload, HTTP multiplexing and request/ response buffering that the advanced platform ADCs provide as application proxies. This benefit can be as much as 18x increase in sustained transaction rate (of Apache) and 40x better utilisation when high-latency is encountered.
Furthermore, the need is growing for advanced traffic shaping, flexible routing policies based not just on request headers but also on request data, transformation of request and response content, more powerful monitoring and bandwidth management.
All of which are generally beyond the scope of the SLB architecture.
Read more on ADC Technolgy at the jetNEXUS BlogSpot.
* Gartner RAS Core Research Note G00164098
For more info on hardware load balancing please visit www.hardwareloadbalancer.com
