For a while now, I’ve been observing a strange phenomenon here at the j-school: Some of our computers respond extremely slowly to our own web site. Take two machines sitting side by side on the exact same 100 megabit network. Both machines are configured identically in terms of subnet, gateway, and DNS addresses. Both have static IPs. Now I try to access the jschool homepage. One browser will have the homepage loaded faster than you can blink. But on the machine next to it, the browser’s status bar will say “Sending request…” for 4-5 seconds, then the page will come in all of a sudden. No other web sites are affected - only our own site, our intranet, and our development server. The affected machines can access external web sites lickety split, but they bog down completely when accessing sites on our own subnet.
The problem affects about half of our Macs, but does not affect any of our Windows machines. It does not seem to matter whether the Macs are running OS 9 or OS X. The problem is not CPU/memory related - we’re talking G4s with 512MBs. Up until a few days ago, my Mac was fortunately unaffected by the problem. But after loading Jaguar onto it (I have a legit copy), my PowerMac, which is my main work machine, is now affected by the problem as well. As webmaster, I reload pages constantly - you can imagine how aggravating this is.
At first I suspected this was a DNS issue, and tried using a variety of alternate DNS servers the university makes available. No difference. Next I decided to bypass DNS by loading the NetInfo database with custom host data. No difference - the problem persists. In fact, the problem persists even when accessing the site by its IP address. Ping times and FTP responses are very fast - it’s just HTTP request times that lag inexplicably. Browser used is irrelevant - I get the same molasses-like behavior with IE, Mozilla, and OmniWeb on this machine.
I’m baffled and frustrated and running out of time to spend on this problem. Is there anything in our Apache configuration that could cause behavior like this? Other theories?
Update: As an experiment, I tried shutting down Apache and starting up OmniHTTPD in it’s place for a few minutes. The problem seemed to vanish! This indicates an Apache configuration problem. All optimizations in httpd.conf are at their default values. But what kinds of optimizations could affect Macs but not PCs, and only some Macs at that?