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Caching in on Web Acceleration

When it comes to code, size doesn't always matter. FineGround Condenser 1.1 ($50,000 and up) provides innovative Web caching with a surprisingly small footprint. At less than a megabyte, this promising server product speeds up downloads and makes better use of existing network bandwidth.

Condenser steps in where traditional Web-caching technologies leave off. Today's edge-caching solutions from Akamai, Cisco Systems, and other vendors put content closer to the user. According to FineGround, edge caching is suitable for static content, whereas Condenser specializes in speeding the transmission of dynamic content like ASP, JSP, Perl, and PHP.

As a proxy server that sits between Web servers and edge-caching hardware, Condenser doesn't require you to change a thing to speed the delivery of Web content. This server runs behind-the-scenes caching requests to Web pages. Whenever a user requests a page, the new and old versions are compared and then only the changed elements are delivered to the client in what's called a delta page.

Delta pages are created through DHTML, which rebuilds only those elements on the client that need updating. Consider a Web page that delivers stock quotes. Much of the page stays the same, save for specific stock information and probably a changing banner ad. Condenser can deliver only what's different to the client.

Administration in Condenser takes a minimalist approach. The product comes with .conf configuration files, which have names familiar to any Linux Webmaster. We installed Condenser on Red Hat Linux 6.2 (the recommended Linux distribution to use with the product; Solaris support is forthcoming), and we were up and running quickly. Despite Condenser's small footprint, the Linux server used plenty of disk space for caching files.

Condenser comes with the most common options enabled. We didn't have to change anything to get started. For more advanced administration (like control of which file types to cache and which to ignore), administrators can turn to the PDF help file, which provides a worthwhile tutorial. Unfortunately, there is no graphical administration module for common configuration tasks, though one is planned.

As with Apache Web Server, you can administer Condenser using remote text configuration file editing via telnet. The product lets you monitor cache performance with log files, which can be viewed with third-party site analysis tools.

Working on a Condenser- accelerated network produces several effects. For one, Condenser uses DHTML to deliver Web content selectively, which means running a fairly recent browser (at least Netscape 4.0, Internet Explorer 4.0, or AOL 4.0 or later) for your clients. Because DHTML actually reconstructs parts of each page using statements that modify the browser object model, cached pages will change the Web source on the fly. (We verified on a variety of clients, however, that content maintained its proper formatting.)

Condenser also requires that cookies be enabled on the end user's browser. It uses cookies as "hooks" into cached content on the server. Without them the technology won't work.

In testing, we saw Condenser accelerate even static pages. The reason is that the product will "zip up" the actual uncompressed DHTML via gzip. But handling dynamic requests is where Condenser really shines. Although this speed increase was modest on a fast LAN, we expect that end users running slower dial-up connections will benefit the most.

We also tested the product with a small e-commerce application powered by JSPs. Condenser still requires that Web requests be processed on the back end, and the performance gains are found in getting content on the last leg of Web delivery. Again, because we used a small network with fast Ethernet connections between nodes, we didn't see the maximum 10X speedup factor that Ground Networks quoted. According to FineGround, the most dramatic speedup will occur when all the changes in a Web page can be packaged up in compressed DHTML that fits inside a single IP packet.

Condenser provides an innovative solution that is sure to get the whole industry thinking about new ways to speed up dynamic content. In the meantime, it is the first to have this approach and deserves a serious look from any organization seeking to get more out of an existing network infrastructure.