On Mon, Jan 25, 2010 at 1:26 PM, Vikrama Sanjeeva <viki.sanjeeva@xxxxxxxxx> wrote: > Hi All, > > Thanks Jeff for the presentation. Its informative. > > Actually, I am trying to calculate what MaxClient I can set. I know my > server is strong and as Danny and you said, setting 600 will not be a risk. > I however, will prefer to do some calculation to drive this value. Since I > am not Solaris command expert, therefore I am having difficulty in doing > calculation. > > My objective is to follow below formula to calculate MaxClient as mentioned > on Apache site: > http://httpd.apache.org/docs/2.2/misc/perf-tuning.html > > "This procedure for doing this is simple: determine the size of your average > Apache process, by looking at your process list via a tool such as top, and > divide this into your total available memory, leaving some room for other > processes." > > As I understand, it says: (RAM Size / Avg HTTPD Process Size) - some > room for other proceeses > > Out of these 3 variables, I am able to conclude: > RAM Size = 32544 MB > Avg httpd process size: 12 MB Hmmm, 12 MB is a typical prefork child process size at least on x86 *including* the httpd executable code; there's only one copy of that executable code living in RAM across the processes. I don't know a handy command to get the size of process-unique data (stack, heap, etc.). It probably requires looking at pmap output? I guess you could use 12MB as an extremely conservative (i.e., worst case) number. Also remember the need for a separate swap space sanity check on Solaris: potential httpd swap use is entire httpd child process size * MaxClients (if using prefork MPM); make sure you have enough swap space make sure you have enough swap space > But how to calculcate "size for other processes" ? One thing I want to > highlight here is that; we are running application server (JBOSS) on same > machine with almost 10 JVM nodes. Average Java process size for these are > 3-4 GB. No other applications are running on this machine. And yes, we are > using "mod_jk" for backend server loadbalancing. Here are some hints on calculating free memory and free swap space: http://forums.sun.com/thread.jspa?threadID=5100488 If you find free memory and free swap space with all the normal services but httpd running, then set aside perhaps 30% for growth of those processes or other things you didn't measure, then you find out how much memory and swap is potentially available for httpd. (BTW, you'd want to duplicate this sort of sanity check every so often -- make sure there is free memory and swap space while everything is running, including httpd.) --------------------------------------------------------------------- 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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