Sun GlassFish Enterprise Server 2.1 High Availability Administration Guide

Creating a Health Checker

To specify the health checker properties, you can use the Admin Console or the asadmin create-http-health-checker command. To do this in the Admin Console, navigate to the HTTP Load Balancers node, expand it and select the load balancer. Then, open the Target tab, and in the Targets table, click the Edit Health Checker link for the desired target. Specify the following parameters.

Table 5–2 Health Checker Parameters




Load Balancer 

Click the Enabled check box to make the selected server available for load balancing. 


Disable Timeout 

The amount of time, in minutes, this server takes to reach a quiescent state after having been disabled . 

30 minutes 


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



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

30 seconds 


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

10 seconds 

If an 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 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.