Apple WebObjects 3.5: Serving - Manual (Page 34)

Administrative Tasks
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Your application’s state-storage strategy affects load balancing. By default,
applications store state in memory in the server. If the application uses this
default state-storage strategy, the instance that processed a session’s first
request must be used to process all subsequent requests. That is, the load-
balancing granularity is per session. If you store state using some other
strategy (for example, if you store state in the file system), true load-
balancing can be achieved; each request from a session can be processed by
any application instance (that is, the load-balancing granularity is per
request).
Increasing the Listen Queue Depth
When an application’s request load is sometimes heavier than other times,
you can increase the listen queue depth to improve performance.
For example, suppose an application can process one transaction per second
and it typically receives transactions at the rate of one transaction every two
seconds. The application’s listen queue remains empty because it can
handle the load. Suppose that at certain times of the day, this same
application receives a much heavier load of two requests per second. At
these times, the listen queue fills up because the application cannot process
as many requests as it receives. If you know that the request rate will
eventually return to the normal load of one request every two seconds,
increasing the listen queue depth will help improve performance during
the heavy load time.
On the other hand, suppose that two requests per second becomes the
normal request load for this application. In this case, no matter how big the
listen queue, the application can never catch up because it only processes
one request per second. In this situation, when the average load is higher
than the application can handle, load balancing is the proper solution.
To increase the listen queue depth, do the following in Monitor:
1. In the Application Inspector, click the More button to show the
Application Instance Inspector in the bottom frame.
2. Scroll down until you see the check box labeled Listen queue depth.
Click this check box.
3. Enter the size of the listen queue depth in the field next to the check
box.
4. Click the Save Settings button at the bottom of the frame.