After a long search through Frontier's code and some help from Steve Hooker on the Manila-dev email list, I discovered the source of the performance issues on my server. Frontier has a builtin httpClient that is smart enough to know when the requested item is sitting in the Frontier database. It is not supposed to search the internet for something in its backyard.

Unfortunately, this wasn't working on my server. My server has two physical IP addresses, one to serve static files through Apache and one to serve Manila's dynamic content from Frontier. This confused Frontier because it thought its IP address was the one that was actually running Apache, so when it compared what it thought its IP address was to a domain name for a site that it is serving, it thought that the site was on a different server.

So rather than using shortcuts to find data in its database, Frontier was going out to the Internet and requesting data from itself. Repeat this multiple times in rapid succession and you bog down the server.

The fix was easy, just tell Frontier what its IP address is and it will figure out the rest.

But this is a lesson that I need to add to my Manila Best Practices pages. If you have Frontier on a server with two physical IP addresses, make sure that Frontier is running on the first one.
Posted by Tom Clifton on 6/29/04; 12:52:47 PM from the Hosting dept.  #