Performance Tuning for Content Manager

Chapter 9. Tuning WebSphere for Content Manager 267

• To calculate the number of busy threads, subtract the number waiting

(Windows NT or 2000 Performance Monitor) from the total available

(ThreadsPerChild).

 Use IBM HTTP Server server-status (this choice works on all platforms, not

just Windows NT or 2000):

a. Edit the IBM HTTP Server file httpd.conf as follows:

• Remove the comment character “#” from the following lines:

- #LoadModule status_module modules/ApacheModuleStatus.dll

- #<Location /server-status>

- #SetHandler server-status

- #</Location>

b. Save the changes and restart the IBM HTTP server.

c. In a Web browser, go to http://yourhost/server-status and click

Reload to update status. Or, if the browser supports refresh, go to

http://yourhost/server-status?refresh=5 to refresh every 5 seconds.

You will see five requests currently being processed, and 45 idle servers.

Our recommendation

Set the value to the expected number of concurrent users. Monitor your system

during normal workload to see whether this value should be changed.

Be sure that this value is high enough for your site if you get a lot of hits. Allow

just enough traffic through to the application server to prevent bottlenecks.

9.4.9 Pending connections queue length (ListenBackLog)

When several clients request connections to the IBM HTTP server, and all

threads are being used, a queue exists to hold additional client requests. The

ListenBackLog directive sets the maximum length for the queue of pending

connections. However, if you are using the default Fast Response Cache

Accelerator (FRCA) feature, the ListenBackLog directive is not used because

FRCA has its own internal queue.

This is often limited to a smaller number by the operating system. This varies

from operating system to operating system. Also note that many operating

systems do not use exactly what is specified as the backlog, but instead use a

number based on (but normally larger than) what is set.

Default values

 511 with FRCA disabled

 1024 with FRCA enabled