Before you undeploy a web application, the application should complete serving requests. The process of gracefully disabling an application is called quiescing. When you quiesce an application, you specify a timeout period. Based on the timeout period, the load balancer uses the following policy for quiescing applications:
If the timeout has not expired, the load balancer does not forward new requests to the application, but returns them to the web server. However, the load balancer continues to forward sticky requests until the timeout expires.
When the timeout expires, the load balancer does not accept any requests for the application, including sticky requests.
When you disable an application from every server instance or cluster the load balancer references, the users of the disabled application experience loss of service until the application is enabled again. If you disable the application from one server instance or cluster while keeping it enabled in another server instance or cluster, users can still access the application. For more information, see Upgrading Applications Without Loss of Availability.
Use asadmin disable-http-lb-application, specifying the following:
Timeout (in minutes).
Name of the application to disable.
Target cluster or instance on which to disable it.
Export the load balancer configuration file using asadmin export-http-lb-config.
Copy the exported configuration to the web server config directory.