We are running a busy Apache/2.0.54 server on 2.6.9 kernel, that suddenly becomes very slow- requests either time out, or it takes 10s to serve a 1K thumbnail. It is usually correlated with load spikes, but not perfectly (by looking at the bandwidth graph) Then it requires a stop/start, and it becomes fast again. This has been happening before, and it was always accompanied with [error] server reached MaxClients setting, consider raising the MaxClients setting in the apache log. We raised MaxClients from 200 to 300, and now it happens with no warning in any logs at all, except with the usual web10 kernel: possible SYN flooding on port 80. Sending cookies. in /var/log/messages (this has always happened when apache hung from overload). What worries me is that there are no log messages in apache logs at all when this happens. This is the relevant part of httpd.conf ServerLimit 300 # we are using prefork MPM <IfModule prefork.c> StartServers 10 MinSpareServers 5 MaxSpareServers 20 MaxClients 300 MaxRequestsPerChild 10000 MaxMemFree 2560 </IfModule> The server has 4GB of RAM and 4GB of swap. When apache "crashes" i.e. becomes very slow, the swap size is still 0 and vmstat shows no swapping. I suspect the problem may be in MaxMemFree 2560 but then I would expect some kind of "out of memory" errors in the logs? Another question: what is the good choice of MaxMemFree value? We want to leave 512MB-1GB or RAM on this machine for other tasks. --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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