Application Delivery Controllers
Application Delivery Controllers The early generations of ADCs, also known as load balancers, operated at the transport layer (Layer 4). The newer ADCs also manage the application layer (Layer 7). While the older load balancers made routing decisions based on information in TCP/IP headers, ADC Layer 7 devices may also direct traffic to different servers based on application-level criteria.Previously, ADCs had been large, expensive devices. But newer products are low-cost and ultra-low power consumption devices-in some cases drawing 5 to 10 times less power than other older products. There are a number of benefits to being an ultra-low, power-consuming device. Some benefits include significant decrease in the use and expense associated with energy, and much lower cooling requirements (further driving down energy costs and associated waste). Wasting less energy and lowering costs Because a server farm can be designed with one or two ADCs for high availability to support hundreds of servers, the low consumption factor can have a significant effect on total energy usage and costs. Low energy consumption network devices enable SMBs to lower their energy bills and reduce cooling requirements. Through robust optimization features such as resource-based load balancing and SSL acceleration, both Managed Hosting Providers (MHPs) and SMB customers can deliver optimum application performance across their servers. Optimizing servers means less energy being wasted and lower operating costs, while promoting a greener environment. An ADC can reduce power consumption and improve performance in an SMB's data center. Companies also see great results in improved efficiency, not only in the data center but in the company's overall network as well. As energy pricing continues to soar, SMBs need to find solutions that will both save money and keep the company competitive in an increasingly IT-intensive world. Peter Melerud is VP of Product Management at KEMP Technologies. Peter has over 20 years experience in designing, building and managing datacenters for large corporations, financial institutions, as well as small and medium-sized businesses. His broad technology expertise covers datacenter server and network communications infrastructure, enterprise business intelligence, data management, content security and compliance technologies. At KEMP Technologies, Peter is responsible for product management and business development of application delivery and load-balancing solutions for the small and medium enterprise (SME) infrastructure market. He can be reached at email@example.com.
The ADC also helps to eliminate bottlenecks by compressing and caching of objects. Rather than having the server handle application requests for the cached objects, the ADC handles them directly by offloading certain content requests from the server. Moreover, the compression and local caching help eliminate network congestion, free up bandwidth and eliminate wasted energy.