Caching - Helping Define The Internet Of The Future

By Jim Thompson
Boardwatch Magazine

Driven by the growth of streaming media, the widespread deployment of broadband access and the growing impatience of users who demand instant response to Web requests, caching is helping define the future of the Internet.

In little more than a year, caching has moved from being an interesting way of increasing access to Web pages to a cutting-edge approach of delivering streaming media, easing the load on servers, saving bandwidth and managing content. Its true strength is in its versatility.

"Caching is key to providing predictable quality to the end user," said Adbelsalam "Solom" Heddaya, vice president of research and architecture for InfoLibria. "For the e-commerce site, the bottom line is the faster they can deliver a Web page or a stream to the user the more likely the user will stay with them."

INTELLIGENT STORAGE

In its basic form, caching provides intelligent storage by saving copies of frequently accessed Web pages or objects in several locations around the edges of the Internet. As a result, when requests are received, the pages can be served up far more quickly than from the original source, which might be halfway around the world. Additional benefits include an increase in the speed of delivery and bandwidth savings.

"We believe that bandwidth will be soaked up a lot more quickly - at a more rapid rate - than it can be deployed," said Greg Govadas, director of marketing for CacheFlow. "If you look at the rich media types in use for music, video and entertainment purposes of all types, plus developments in the wireless and personal appliance space, you can see that traffic is increasing rapidly. It's clear that caching will always be necessary."

Bandwidth is not infinite. New trends and applications are emerging daily that are soaking up available bandwidth. As Heddaya explains, three major trends are at work in absorbing bandwidth. "One trend is the increase in the number of people using the Internet. Another is an increase in the speed of the last hop or the last mile." The equation becomes complex because an individual can purchase bandwidth, through cable or DSL, on the edges of the network, but the center of the network - the backbone - is unable to deliver bandwidth equal to that available to the end user. "There is a mis-match between the center and the edges of the Internet," notes Heddaya.

A third trend is that machines - computer sitting on your desk - are beginning to assume many of the routine tasks we now perform ourselves. An entire industry dedicated to making your computer less dependent and more autonomous is emerging. In the near future, your computer will do much of the browsing for you. Armed with a set of instructions and criteria, the new "intelligent" browser will surf the Net for you while you sleep.

"There's a lot of effort going into making your computer work on your behalf without human intervention," said Heddaya. "That means the browser will be collecting much more information than the individual will actually look at. When that happens, the demand for bandwidth will increase once again." <2>PERFORMANCE IS KEY

As any user will tell you, when it comes to using the Internet, performance is the key. Delays of any kind mean users will tune out. Expectations for fast delivery are increasing as broadband access, thanks to the widespread deployment of DSL and cable modems in the "last mile," becomes more accessible and more common for the average user. Again, a copy that is closer to the user results in a more efficient use of broadband capabilities and provides a more positive user experience.

"Performance is a mix of content acceleration and content distribution. Both are trying to do the same thing," said Govadas. "Both are trying to get Web content to users as quickly as possible without choking the back end server network infrastructure.

"Caching is a great way of shielding those back end servers by insuring they are only processing the needed transactions and database look-ups and the cache is handling all the popular objects."

Ironically, not long ago, streaming media and the use of dynamic pages were seen as reasons for the ultimate demise of caching. But instead of signaling the beginning of the end, streaming media is leading the way to a bright and important future for caching. Streaming media is performance-sensitive, making caching that much more important for performance.

STREAMING MEDIA

"In the next six to 12 months caching will have morphed to support streaming media and will be in the early stages of supporting broadband streaming media," predicts Heddaya.

Many believe that streaming media will never become a reality without the boost provided by caching. For example, a single major multimedia event might require a stream of 500 Kbps. If a million people are all trying to access the event at the same time, it will require 500 Gbps. Without caching you have a disaster waiting to happen. Only by storing data at the edges of the Internet, using caching, can such events be possible, many argue.

Predicting the future is anything but an exact science. Predicting the future for a specific technology, like caching, is even more difficult. But one thing is clear - the inherent and basic performance of the Internet is not likely to improve. Don't look for network technology to catch up with load demands. Even with the deployment of fiber and high-speed lines, Internet performance will not accelerate without help from technologies like caching.

Heddaya has an interesting perspective on the need and the potential use of bandwidth. In designing a theoretical "Internet of the future," he begins by applying the currently used techniques in the design for interconnecting super computers in a single environment with very high bandwidth running over fiber. The combination of these elements creates, in theory, what he calls the "non-blocking Internet" or an Internet that "has no congestion whatsoever."

SPEED OF LIGHT IS TOO SLOW

While this may sound like the perfect Internet world, Heddaya points out that two things happen. "One is that we are suddenly limited by the speed of light in fiber - which is approximately 50 milliseconds round trip from Boston to San Francisco and about 70 milliseconds from Tokyo to San Francisco." (Note: The speed of light in fiber is about 60 percent of the speed of light in space or in a vacuum.) This limitation of the speed of light, essentially, "rules out serious interactive applications across the Internet." His logic is that if we combine streaming media, which is "sensitive to bandwidth but not to response time," with interactivity, the result is a product that is unacceptable to the user.

"You can't provide an acceptable level of performance for the user when you have a server on one end of a fiber line that is 3,000 miles long, even if the fiber is dedicated to your personal use. The reason is simply that the speed of light is much too slow. The speed of light in fiber is far slower than the human response time requirements." This slowness is magnified when you extract the human factor and consider communication between computers.

"For a computer that is capable of executing billions of instructions per second, and responds in a few milliseconds, to wait for another computer for 50-milliseconds, is like an eternity," added Heddaya. "It's completely out of the question to execute interactive applications, such as games or e-commerce, across the Internet even when bandwidth is infinite and free."

Haddaya notes that on this theoretical "Internet of the future" moving files across the country would result in "your normal day-to-day work being slowed by a factor of 10. For the Internet to be responsive to the growing demands placed upon it, interactive applications will move into the fabric of the network to run on caches."

Content providers are rapidly realizing that caching is a fundamental technology. Accessing data directly from the origin server rarely makes sense. As the Internet matures, the basic structure will be used, not to move content from server directly to browser, but from server to server and then from the closest server to the browser. The most efficient model for the Internet is to move Web pages, data and other content by creating intelligent copies using intelligent storage.

Heddaya sees the caching platform metamorphosing to "primarily serve the Web site instead of the access customer," a trend InfoLibria refers to as Content Distribution and Delivery. "With Content Distribution and Delivery, the Web site becomes the customer for the service rather than for the end users or even for the network operator who wants to save bandwidth.

"This trend is occurring primarily in the U.S., but there is intense interest worldwide. I predict that this year we will see the big names in telecommunications announcing Content Distribution and Delivery services."

CACHING IS EVOLVING

Value-added services - which translate into more money - are also a part of the future lead by caching technology. "We believe that caching will not always be deployed only for performance purposes," noted Govadas. "For example, we're looking at how a cache can change the content based on the location of the cache or the location of the user who is coming into the cache." An example might be someone located in Los Angeles who requests a page that is located on a server in New York. The person making the request could receive an advertisement that is localized to the Los Angeles area. "Caching deployed at the edge is a good way to do this," added Govadas.

John Scharber, chief technology officer at Entera, agrees that caching is evolving into something far more than just a performance booster. "Caching will change conceptually from the models we have today to becoming the data managers of different types of content." He also sees caches being used to manage archival and database content.

"I believe we will also see a lot more focus on providing distributed network application services via caches. The caching platform will become a gateway, not only for managing the deployment of the content, but for integrating it with ASPs and other services on the network. Caching will certainly be a core building block on what the next generation is built upon," added Scharber.

Erv Johnson, director of technical marketing for ArrowPoint believes the future also involves "leveraging geographically distributed data centers for more advanced content delivery" along with a greater emphasis on the delivery of broadcast signals to fill personal needs over the Web. "I see a combining of interactive broadcast with delivery of personalized content," said Johnson. He adds that technologies like caching will help the Internet become content aware. "Only when, and if, the network knows the difference between requests and interactive, static and broadcast data will it become a useful tool for the future."

Caching is becoming cornerstone for building the future of the Internet. It's a technology that can be molded to meet the ever-changing nature of the Internet. The value of the technology will become greater as we move into the next phase of the electronic revolution. Hand-held, wireless devices will soon dominate the landscape, just as cellular phones are now the favorite toy of the "tuned-in" generation.

These portable devices will provide instant and constant contact for business and private use. Their small screens will require a new method of delivering data that is tailored for the limited resources of devices. Caching is perfectly poised to be this technology since it can adapt the data from a full Web site to fit the limited capacity of hand-held devices.

The shirking availability of bandwidth is another reason for caching. As Heddaya points out, even with unlimited, dedicated bandwidth over a fiber link, there is still a significant lag in the speed of data delivery. If you factor in current usage patterns and add the ever-increasing growth of demand for data over the Internet, it's easy to see that caching is the right technology to carry us into the future.

"The dominant benefits of caching will vary over time, but the technology will be required," said Heddaya.