We set up a special piece of software (called FireSite) that would allow us to dynamically feed all our graphics from the Pittsburgh DS-3 lines at our ISP and our text files from our local machines (which we needed to constantly have hands-on access to) over the ISDN line. FireSite was also smart. It monitored the remote servers and if the remote Pittsburgh operation went down, it'd feed graphics from our ISDN line again. Fortunately, that's never happened.

This distributed server approach worked and since then, whenever we've launched an issue, readers have pulled text from our Princeton servers and graphics from our Pittsburgh machines. And the bottleneck was no more…until we introduced the Mobile Editions.

Only this time, the bottleneck was harder to work around. FireSite distributed graphics, it didn't distribute text files. So, in a big rush, we modified ZENPRESS to build both a local feed and a distributed feed version of our Mobile Editions. When it's time to download the Mobile Edition, you'd download the mobile home page and the news page over our ISDN feed and the remaining 12 pages over the twin DS-3 feed from Pittsburgh.

At least that was the theory. In practice, we had to go back to the wonderful folks at AvantGo (Brad, you're a friggin' god!) and ask them to update their database for every subscriber. Here's what happened.

When we first built the Mobile Editions, everything was a relative link (in other words, AvantGo expected and we provided all the files on the same server, in the same file system). But when we distributed the load between Princeton and Pittsburgh, we needed to use links that were no longer relative. Some of our subordinate pages were linked by relatively complex URLs that specified the drive on the remote machine.

Technically, this would work. But when AvantGo set up our channel, they set it up so all new subscribers would only have relative links. But we needed absolute links, outside of the normal heirarchy. And so our distributed feed of the Mobile Editions didn't work - at least for a while.

It took about a day, but the folks at AvantGo wrote some software that updated all the subscriptions for our publications so they no longer required local links. And so, the worlds first distributed-server based mobile magazine network was born.

And our ISDN line was able to breathe again.

Conclusion
There's no doubt we'll continue to modify and tweak our Mobile Edition structure as we learn more. And, as we learn more, we'll pass it along to you. Thanks for reading!

Michael Compeau is a Contributing Editor for PalmPower Magazine as well as the VP of Business Development and Planning for Cutting Edge Software (at http://www.cesinc.com), a subsidiary of Mobility Electronics.