Sun Microsystems Netscape Enterprise Server, Руководство администратора

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Chapter 10, Configuring the Server for Performance 257
Common Performance Problems
The best way to tell if your server is being throttled is to look at the
WaitingThreads
count. If this number is getting close to 0 or is 0, then the
server is not accepting new connections right now. Also check to see if the
number of
ActiveThreads
and
BusyThreads
are close to their limits. If so,
the server is probably limiting itself.
Tuning
See “About RqThrottle” on page 229 .
Cache Not Utilized
If the cache is not utilized, your server is not performing optimally. Since most
sites have lots of GIF or JPEG files (which should always be cacheable), you
need to use your cache effectively.
Some sites, however, do almost everything through CGIs, shtml, or other
dynamic sources. Dynamic content is generally not cacheable and inherently
yields a low cache hit rate. Don’t be too alarmed if your site has a low cache hit
rate. The most important thing is that your response time is low. You can have
a 0% cache hit rate and still have very good response time. As long as your
response time is good, you may not care that the cache hit rate is low.
Checking
Begin by checking your Hit Ratio. This is the percentage of times the cache was
used with all hits to your server. A good cache hit rate is anything above 50%.
Some sites may even achieve 98% or higher.
In addition, if you are doing a lot of CGI or NSAPI calls, you may have a low
cache hit rate.
Tuning
If you have custom NSAPI functions (nametrans, pathcheck, etc), you may have
a low cache hit rate. If you are writing your own NSAPI functions, be sure to
see the programmer’s guide for information on making your NSAPI code
cacheable as well.