Cisco Personal Communications Assistant (Cisco PCA or CPCA) implements
a throttling mechanism to control the load that browser requests put on the
Cisco Unity server. The throttling mechanism returns a "Server is busy" message
to users when the server begins to overload. A set of parameters defined in a
configuration file controls the throttling. If you change the values of these
parameters to allow more load on the server, the result is more users that are
able to concurrently use the system without getting the "Server is busy"
message. However, more load from web traffic implies that the server might not
have enough capacity left to process voicemail traffic.
The parameters are initially set to the same value regardless of the
hardware platform due to a limitation of the Cisco Unity installation program.
The values set by the installer are appropriate for the low-end platforms but
too stringent for high-end platforms, which can handle more load. This means
that high-end platforms do not scale to their full potential out of the box.
This document provides instructions on how to change the parameters to their
optimum values on high-end platforms. The values for these throttle parameters
were selected carefully. Use only the value appropriate to your platform as
indicated in the procedure in this document. Also note that if you upgrade
Cisco Unity or re-run Cisco Unity setup to change features, it might reset the
parameters to the default values. In this case, you need to repeat this
Note: Ensure that Cisco Unity is properly installed and works before you
use the information in this document.
There are no specific requirements for this document.
The information in this document is based on these software and
Do not use the information in this document on servers or software
releases other than the ones in this section. This action can destabilize your
Cisco Unity setup, and Cisco does not support it.
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
The throttle parameters are in an XML file. For platform overlay
numbers 2 and 3, you must edit the file and restart the web server on Cisco
Unity to change the parameters. For platform overlay number 1, you can skip
this procedure, as the default throttle parameter value allows for the
supported load for this platform.
Note: Access to Cisco PCA is disrupted while the web server restarts.
Complete these steps:
The root directory of your Cisco Unity installation is
<commserver>. For example, C:\commserver.
Locate the file web.xml and make a copy of it.
Open the file with a text editor such as Microsoft Notepad.
As applicable, change the value of the max-requests setting from 3
to one of these values, based on your platform:
Platform Overlay Number
Value of max-requests setting
3 (same as the default - no need to change this
Save the file and close the text editor.
Restart the Cisco Tomcat service from the Services MMC control
If failover is in use, repeat step 1 through step 6 on the
secondary Cisco Unity server.
Warning: If you upgrade Cisco Unity or re-run Cisco Unity setup to change
features, it might reset the parameters to the default values. If this happens,
repeat the steps in this document.
If you accidentally change other contents of the web.xml file:
Compare the contents of the current web.xml file with the backup copy
made earlier and make sure that there are no other changes if this happens.