Determining Memory Requirements
Sizing and Configuration 3-3
Determining CPU Requirements
For most applications, the majority of the CPU utilization is spent in processing the
application’s code. The CPU requirement of any application depends on its
complexity and workload, as shown in Tabl e 3–2 .
You will need to monitor the CPU requirements of applications throughout the
development cycle. See Chapter 2, "Monitoring Your Web Server" for information
on how to do this.

Secure Sockets Layer Impact on CPU Requirements

Secure Sockets Layer (SSL) is a protocol used for transmitting documents securely
over the Internet. URLs for Web pages that require an SSL connection begin with
https instead of http.
Establishing an SSL connection is costly in terms of response time and CPU
utilization. For example, a request with a response time of 0.5 seconds without SSL
generated a response time of 1.7 seconds with SSL (measured on an internal 100
Mbps network). Most of the performance cost in using SSL is in establishing the
connection (approximately 125 ms of CPU time per connection on a 336 Mhz
processor).
The high connection cost is incurred for the first connection in a client’s SSL session,
because the HTTP Server can cache the SSL session information, reducing the
overhead for subsequent connections. For more information, see "SSL Session
Caching" on page 4-10.
Determining Memory Requirements
This section discusses memory requirements for the following components:
Table 3–2 Application CPU requirements
Application CPU requirement
(per request)
Static page, 20K 5 ms
Simple servlet, JDK 1.2 20 ms
Simple servlet, JDK 1.1.8 40 ms
Medium application 100-200 ms
Complex application 400-600 ms