Sun Java System Application Server Enterprise Edition 8.1 2005Q2 High Availability Administration Guide

Creating a Health Checker

To create the health checker, use the asadmin create-http-health-checke r command. Specify the following parameters:

Table 4–2 Health Checker Parameters

Parameter 

Description 

Default 

url 

Specifies the listener’s URL that the load balancer checks to determine its state of health.  

“/” 

interval 

Specifies the interval in seconds at which health checks of instances occur. Specifying 0 disables the health checker. 

30 seconds 

timeout 

Specifies the timeout interval in seconds within which a response must be obtained for a listener to be considered healthy.  

10 seconds 

If an application server instance is marked as unhealthy, the health checker polls the unhealthy instances to determine if the instance has become healthy. The health checker uses the specified URL to check all unhealthy application server instances to determine if they have returned to the healthy state.

If the health checker finds that an unhealthy instance has become healthy, that instance is added to the list of healthy instances.

For more information see the documentation for create-http-health-checker and delete-http-health-checker.