HP WebQoS Peak for HP-UX Concepts and Operation Guide

Chapter 3 31
HP WebQoS Peak for Netscape
Configuring HP WebQoS for Netscape
Company B. Company A’s home page is located at
/web_pages/company_a/index.html and Company B’s home page is
located at /web_pages/company_b/index.html. To monitor each site’s
traffic, add the following to the configuration file:
isolate.pattern /web_pages/%[^/]
Refer to documentation on the sscanf command for more information on
constructing the pattern.
After editing the configuration file, restart the web server.
Detecting Failed Servers in a Cluster
When a web server is running, it periodically broadcasts a message that
it is up. When a web server is shut down, it broadcasts a message that is
unavailable. When a web server is not running, it does not broadcast a
message.
Each web server in a cluster listens for these broadcast messages. Based
on the messages received or not received, it will mark each system as up
or down.
The web server marks a system as up when it receives the appropriate
broadcast message from that system. The web server marks a system as
down when it receives the appropriate message or it fails to receive a
message after a specified number of broadcast intervals.
In the HP WebQoS
/opt/ns- server_name / server_id /config/hpac/config.ac
configuration file, you can configure how often messages are sent
(broadcast interval) and how many messages can be missed before the
system is marked as down. The parameters are:
cluster.keepalive.interval 60
cluster.keepalive.misses 3
where the interval is measured in seconds. The values given are the
default values.
If you configure these parameters, the web server must be restarted.
Also, all systems in the cluster should use the same values for these
parameters.
Decreasing the broadcast interval decreases the time it takes to detect a
failure. However, it also increases broadcast traffic.
Sometimes, not all broadcast messages are received. Therefore, the