Content Delivery From The Source

Clearway's FireSite sits on the origin server and ensures that content delivered to the network edge is always fresh.

"N+I Atlanta is really our coming out party. We've been aggressively going after initial customers in the past few weeks, since leaving beta stage."
—Clearway CEO Alexander Globus

Lisa Phifer
VP Core Competence, Inc.

Content delivery networks (CDNs) such as those offered by Akamai, Digital Island, Exodus, Mirror Image, and Orblynx are services that mirror high-bandwidth, high-demand content at the network edge for reliable, fast access. CDN services first appeared just over a year ago. Since then, interest in CDN services has rocketed.

A February Internet Research Group study predicted the content distribution and delivery market will reach $6 billion by 2004.

Recently, players have started bickering. In late August, Cisco launched a content vendor alliance absent market leader Akamai. When Digital Island was awarded a "fingerprint" patent in September, Akamai filed a patent infringement suit, and Digital Island said it would file a countersuit. There must be something really valuable here to instigate this kind of legal jousting.

This week, Clearway jumps into the CDN market. Clearway's FireSite is a content delivery service with a revolutionary twist: a distribution agent on the origin server.

The Clearway difference
Many CDN platforms tag content to be distributed to edge servers. For example, Akamai customers run a utility that selectively converts URLs into Akamai Resource Locators that route requests to the nearest edge server. But tagging adds administrative overhead and requires specialized or upgraded infrastructure that understands tags.

Some CDN providers use a cache hierarchy to pull content to the network edge, others such as Orblynx even reactively push content based on past use.

In each of these approaches, replicated content must be periodically refreshed to maintain synchronization. When edge content gets stale, requests ultimately circle back to the origin server.

"We're entering the market with what we think is a better approach," said Alexander Globus, Clearway CEO. "What makes us different is our decision to build a complex agent that resides on the origin server." The FireSite agent can see content change, query the operating system, and assess server load. "Not only can we gather this info," said Globus, "But we can take constructive action based on it. We can do all of the processing, replication, and synchronization required for content distribution without administrator involvement."

The FireSite agent is completely transparent to the origin server and to existing infrastructure the hoster may use for high availability or load balancing. "Our agent rewrites embedded objects so that they can be served up by the CDN", said Globus. "Agents have a lightweight database that tells them where content is located. They'll rewrite HTML with the precise IP address where content is located, so there is no DNS lookup or latency, no cache miss that ends up bringing the request back to the origin server. We don't rewrite the HTML until it is flying out the door — this lets us make the best decision possible."

FireSite is a turnkey content delivery solution. "To use FireSite, all you need to do is drop our agent software onto your content server," said Globus. "The FireSite agent replicates content, making decisions about when and where content is needed, and any necessary HTML modifications."

An engineering challenge
Performance demands and thousands of possible plug-ins make the origin server a truly caustic environment. "We absolutely can't slow the origin server down," said Globus. "Our agent must be stable and portable. This is a monumental engineering task that our competitors have shied away from — not because it isn't the right thing to do, but because it's hard to do right."

Why is Clearway convinced that FireSite can meet this challenge? "We've used automated testing programs to pound servers with 10 million pages per day without seeing any material slow-down," said Globus. "Whenever development makes changes, our QA department puts the agent through thousands of hours of testing. We understand very well, and have developed a huge knowledge base about, the kinds of problems that can occur when running a software agent on a web server."

Getting started
According to Globus, FireSite installs in minutes — just run a setup program on each server, making a few configuration selections.

"At that point the administrator can go to lunch," said Globus. "The agent communicates with our network management system that's allocated space across the CDN, and then looks to see what is actually happening to determine what content to push." The agent identifies large objects that are used frequently and it watches where content is being used. Objects assigned highest priority are pushed to a single CDN server; that server in turn pushes content to other servers where storage has been allocated.

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