Peter Horizontal scaling specifically Clustered solutions will address the need--
"Vertical scaling is achieved by increasing the number of servers running on a single machine, whereas horizontal scaling is done by increasing the number of machines in the cluster Horizontal scaling is more reliable than vertical scaling, since there are multiple machines involved in the cluster environment, as compared to only one machine. With vertical scaling, the machine's processing power, CPU usage, and JVM heap memory configurations are the main factors in deciding how many server instances should be run on one machine (also known as the server-to-CPU ratio)." Info courtesy of http://www.onjava.com/pub/a/onjava/2004/03/31/clustering.html HTH Martin -- ********************************************************************* This email message and any files transmitted with it contain confidential information intended only for the person(s) to whom this email message is addressed. If you have received this email message in error, please notify the sender immediately by telephone or email and destroy the original message without making a copy. Thank you. ----- Original Message ----- From: "Peter Crowther" <[EMAIL PROTECTED]> To: "Tomcat Users List" <users@tomcat.apache.org> Sent: Monday, August 14, 2006 3:57 AM Subject: RE: CPU usage and response time > From: Eickvonder Bjoern [mailto:[EMAIL PROTECTED] > Is the following formula correct? > > (response time if 100% CPU would have been granted for the request) / > (percentage of CPU actually granted) = response time No. If CPU was the only resource, and thread switches were free, then this would be close. However, thread switches take time (which means less time for processing servlet code) and there are other resources that influence almost all response times - database, memory, disk and so on. > And second what parameters do actually influence the percentage of CPU > that is actually granted for a request and can I adjust them? How much time the OS allocates to Tomcat's threads. On most OSs, Tomcat threads map to native threads so the OS schedules each thread. Depending on the OS, you *might* be able to reach in and adjust thread priorities, but I wouldn't recommend it as a general solution. What are you trying to achieve? Tuning the application so that some requests get relatively more CPU than others? - Peter --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
