Web accelerators solve network bottleneck
The popular Web site serves as a hub for consumers and merchants, offering comparison-shopping as well as research on consumer buying behavior. At BizRate.com, visitors can search the comparison-shopping engine for good deals on merchandise ranging from men's jeans to cocktail shakers, then buy an item from a particular merchant. BizRate also conducts customer satisfaction surveys at the point of sale for about 2,500 Internet merchants, including Barnes & Noble and Proflowers.com. BizRate's research group compiles reports from the surveys and sells them to the merchants. BizRate also sells category-based reports to businesses such as media and credit card companies.
BizRate has seven to eight million unique visitors each month, according to Jody Mulkey, data systems vice president. In fact, Jupiter Media Metrix reported in April that BizRate was the sixth fastest growing Web site, based on a 36.4 percent increase in the number of unique visitors between February and March 2002.
Ordinarily, more bandwidth would be necessary to handle the continuous surge in traffic to the Web servers. But BizRate decided to try something less costly before going that route, Mulkey says. The six-year-old Internet company purchased two of Redline Networks' T/X 2400 Real-Time Acceleration (RTA) appliances to manage its high-volume traffic.
The appliances--loaded with two 1.13GHz processors and 2GB of memory and an operating system designed to react quickly to client and server requests--serve as connection managers for the BizRate network, providing up to 50,000 simultaneous, permanently open 100Mbps TCP connections to its Web servers. Without them in the network, BizRate's servers were bogged down making and dropping TCP connections to users' PCs.
To further improve performance, the appliances use two proprietary optimization engines to compress the Web pages the servers then send out to a client. One engine removes data that has no effect on a Web page's appearance. The other engine uses compression algorithms that HTTP/1.1-compliant browsers understand.
Before installing the two T/X boxes, BizRate's Web servers were slowing down because of a surge in page requests from dial-up users. (Broadband users did not experience the same delays loading the BizRate pages.) The traffic increase wasn't tremendous, but the dial-up connections from the clients were keeping the Web servers' TCP connections open for too long.
At the time BizRate installed the T/X 2400s, the company was buying bandwidth at peak rates. "Now you can buy bandwidth from most providers per megabit," he says. But when the company bought the Web acceleration appliances, bandwidth was only available in tiers of 0 to 10 Mbps, 10 to 20 Mbps, and so on. With each tier came a $10,000 to $15,000 incremental cost, Mulkey explains.BizRate spent $20,000 for the two T/X 2400 boxes, and saw a full return on the investment in about six weeks. Mulkey's impetus for making the purchase was simple: "If I can stay under one tier [with the appliances] for two months, I'm done. I've paid back my investment." Even though bandwidth prices dropped substantially, causing the anticipated ROI to take longer to realize, the T/X 2400s also have extended the life of BizRate's server farm. "We've been able to grow the number of pages without growing our server farm as quickly," he says.
Mulkey says he was pleasantly surprised by the results. "Of course, I was sort of a cynic," he admits. "Redline was an unproven company to me at that point." What interested Mulkey in buying the T/X 2400 appliances was that they could plug easily into BizRate's network. "We looked at a couple of different products. One was some company that [had the acceleration function] on a specialized network card." That scenario presented too much risk for the BizRate network. "I don't want to take apart all my servers and install some network card from a company I've never heard of." With the Redline devices, Mulkey says he can turn them off without affecting the rest of the network.
The two T/X 2400 appliances sit between a Cisco LocalDirector and Dell Computer 1650 Linux-based Web servers, each equipped with two 1.4GHz Intel processors and 4GB of memory. BizRate runs between six and 20 Web servers, depending on the amount of traffic Mulkey expects the site to get. The servers run Apache, an open-source Web server software, as well as BizRate's Linux-based application server. Behind that, BizRate has two Sybase Adaptive Server Enterprise (ASE) 12.1 databases, operating on Sun Microsystems Enterprise 4500 and 3500 servers. One database server holds merchant information, while the other contains consumer data. BizRate keeps all its equipment at a Level 3 Communications collocation facility. All its Internet activity is pushed through Cisco routers and switches.
After almost a year of use, BizRate is happy with the Redline appliances. The company has even enjoyed an unexpected side benefit since they were installed. Throughout the 2001 Christmas season, which kicks off in September for BizRate, staffers found they could focus on other parts of the business, including Web site development and database programming. "My team is not glued to the monitors, which we had to do before," Mulkey says. Then, IT staffers constantly were watching the server activity to make adjustments when the TCP connections got hung up. Today, the staff is just as busy, he says, but it is focusing on pre-empting problems through system maintenance, upgrades, and other value-added projects. The T/X 2400 "adds a little bit of peace of mind," he adds. "That's definitely worth $20,000."
Kimberly B. Caisse, a technology writer in Westminster, MA, writes regularly about networking issues.
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