HP WebQoS Peak for HP-UX Concepts and Operation Guide

Chapter 5 53
HP WebQoS Peak for the Apache Web Server
Integrating HP WebQoS with the Apache Web Server
client. For instance, the customer whose access has been rejected may be
given a reason for the rejection and a suggestion of a more opportune
time to return to the site. The extra information is more likely to
dissuade users from retrying immediately, without discouraging them
from returning to the site in the future.
The location of the file holding this custom response is specified with the
directive HPACRejectPagePath. For example,
HPACRejectPagePath <file_path>
If the policy is set to rejectpage, but the rejectpage path has not been set
(or cannot be accessed), the server response is the same as the reject
policy server response.
The defer policy is a special case of rejection. The admission of a session
rejected under this policy is merely postponed to a future time slot, when
the session will automatically gain access to the server. Once a deferred
session is admitted, it is handled as a priority session.
A countdown web page is returned to the user agent in response to
deferred requests which shows how long the user has to wait in line.
You can set the rate (per minute)at which deferred sessions are admitted
to the server with the HPACDeferredAdmitRate directive. The default for
this directive is “10” sessions per minute. For example, to set the rate at
which the deferred sessions are admitted to the server to 5 sessions per
minute, use the following directive in your configuration file:
HPWebQoSDeferredAdmitRate 5
In the example above, one session will be admitted every 12 seconds. (At
this rate, for example, if there are only 5 sessions waiting for admission,
they will all gain access during the next minute. If there are 20 sessions
waiting for admission, the last 5 sessions will be admitted 4 minutes
later than the first 5.)
When setting the admission (allocation) rate of deferred sessions, make
sure that the system has adequate capacity to handle it. Take into
account that some of the deferred sessions may not come back (because
the user gave up), and compensate accordingly.
Monitoring the % Priority Requests and Last Allocation Delay
statistics can help in setting a realistic allocation rate. The first statistic
will show the system's load due to priority sessions. Reduce the
allocation rate if this number approaches, or is over, 50%. The second
statistic shows how long the user of a deferred session had to wait before