Primer: Application Acceleration

By Baselinemag  |  Posted 2006-07-06 Email Print this article Print
 
 
 
 
 
 
 

How application acceleration systems reduce latency and cut bandwidth.

What is it? A system that speeds up the performance of centralized applications for remote employees, customers or partners who access those applications over a network.

Why do applications need to be accelerated? Companies are increasingly consolidating applications and servers at a central location, to manage them more cost-effectively or to meet regulatory requirements for data security and backup. These include anything from corporate Web portals to enterprise resource planning systems. Trouble is, applications are often designed as if they're always going to be accessed over a low-latency, high-bandwidth local network, says Jason Needham, director of product management at F5 Networks, which sells a line of application acceleration products. "But there's a natural barrier when you're trying to send data long distances," he says.

How does it work? Some application acceleration systems require devices on either end of a network connection (e.g., at a headquarters and a branch office), while others sit in front of servers in a data center to make access to those servers more efficient. These devices address the two main factors that impede performance—latency, the time delay between two computers talking to each other over a network; and bandwidth, the amount of network capacity available to applications—using three main techniques:

  • Protocol optimization fools an application into thinking it's talking to a locally connected computer, instead of one that's hundreds of miles away. A typical Web page, for example, involves 10 to 30 round-trip communications between a browser and a server; an application acceleration device handles certain standard commands (such as those required by Internet protocols) to reduce the actual number of round trips.

  • Content caching stores data that is likely to be used again and is unlikely to change, instead of requiring computers to retrieve it from the source every time.

  • Compression reduces the amount of data crossing the link—squeezing it into smaller packets, which are then combined into a larger "meta" packet—making it faster and more efficient to send across a network.

    Who are the vendors? Players include Blue Coat Systems, Cisco Systems, Citrix Systems, Certeon, Coyote Point Systems, Expand Networks, F5, Juniper Networks, Packeteer, Radware and Riverbed Technology. Gartner sizes the market at $1.2 billion in sales in 2005. A growing subsegment: products that specifically accelerate eXtensible Markup Language (XML) traffic, such as those from IBM's DataPower unit and Reactivity.

    How much can this actually speed up applications? Vendors claim their products can improve overall throughput 5 to 10 times or more, depending on the characteristics of the application and the network.

    Really? Yes, say analysts, though your mileage will vary. "I've had many enterprises anecdotally report to me that the application acceleration technology did exactly what it claimed it would do," says Forrester Research analyst Rob Whiteley. But performance gains won't necessarily be better by an order of magnitude. Two years ago Cintas, a uniform supply company in Cincinnati, deployed 250 application acceleration devices from Peribit Networks (since acquired by Juniper) at offices and plants throughout North America that connect to a central enterprise resource planning application. Mark LeClair, Cintas's telecommunications manager, says the project cut average bandwidth consumption by 40%. "We were out of bandwidth," he says, "and this bought us some time instead of having to upgrade to faster pipes."



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