Moodle 2 installation that I use is not only used for running courses but also is used as content management system and has some traffic. Apache after tuning looks good along with APC PHP accelerator but considering 5x or even more load due to some event in future, I thought of giving lightweight server a try using it on another port. I chose Cherokee because some comparisons of lightweight servers pointed out towards, "easy to configure" aspect of Cherokee which I was looking for (incidentally, Cherokee installation/configuration turned out to be not really easy on an Ubuntu 10.04 machine). After installation, configuration and tweaking some setting, Cherokee appeared to be using far less RAM and responded quickly. However, in stress tests with large number of concurrent users some failed requests of the type, "Non-2xx responses" showed. The server error log file shows something like, "Could not unlock spawning semaphore...". The same test using Apache incidentally shows no failed requests with same number of concurrent users, but either the response time would be large or memory would be consumed depending on how Apache is tuned. As, the Cherokee installation under load would sometimes say, "503 service unavailable" doing some search pointed out the issue as php-cgi crash under load. Some tuning in php-cgi can possibly make it more stable. But, then if the site goes down at 3 AM due to php-cgi crash, who fill fix it? It does not appear to restart on its own. Won't a slow but stable Apache be better under such condition which would become fast once the load decreases? While doing the search to fix the issue, it appears that this php-cgi issue is there with some other lightweight server(s). This whole experiment was to decide the course of action under load without increasing RAM and unless php-cgi issue is fixed, tuned Apache seems to be the way for the moment. I wonder how much worth is the buzz about lightweight servers unless the php-cgi issue is resolved (for php intensive sites). Any thoughts, workaround, solution would be welcome.