Sun Microsystems 820433510 manual 152

HTTP Listeners

The Keep-Alive subsystem periodically polls such idle connections and queues those connections with activity into the connection queue for future processing. From there, a request processing thread again retrieves the connection and processes its request. The Keep-Alive subsystem is multi-threaded, as it manages potentially tens of thousands of connections. Efficient polling techniques are used, by dividing the number of connections into smaller subsets, to determine which connections are ready with requests and which of those connections have idled for sufficient time to deem them closed (beyond a maximum permissible Keep-Alive timeout).

The HTTP listener’s server name is the host name that appears in the URLs the server sends to the client as part of a redirect. This attribute affects URLs the server automatically generates; it does not affect the URLs for directories and files stored in the server. This name is normally the alias name if the server uses an alias. If a client sends a Host: header, that host name supersedes the HTTP listener’s server name value in redirects.

Specify a redirect port to use a different port number from that specified in the original request. A redirect occurs in one of these situations:

■If a client tries to access a resource that no longer exists at the specified URL (that is, the resource has moved to another location), the server redirects the client to the new location (instead of returning a 404), by returning a designated response code and including the new location in the response’s Location header.

■If a client tries to access a resource that is protected (for example, SSL) on the regular HTTP port, the server redirects the request to the SSL-enabled port. In this case, the server returns a new URL in the Location response header, in which the original insecure port has been replaced with the SSL-enabled port. The client then connects to this new URL.

Specify also whether security is enabled for an HTTP listener and what kind of security is used (for example, which SSL protocol and which ciphers).

To access a web application deployed on the Enterprise Server, use the URL http://localhost:8080/ (or https://localhost:8181/ if it is a secure application), along with the context root specified for the web application. To access the Admin Console, use the URL https://localhost:4848/ or http://localhost:4848/asadmin/ (its default context root).

Because a virtual server must specify an existing HTTP listener, and because it cannot specify an HTTP listener that is already being used by another virtual server, create at least one HTTP listener before creating a new virtual server.

152 Sun GlassFish Enterprise Server 2.1 Administration Guide • December 2008