Environment tags configure class-loaders, logging, authentication, EL variables and control, and resources like databases, JMS queues, EJB servers, and web service clients. Many of the resources are stored in JNDI or in EL variables for later assemply.

Any environment resource can appear in any of Resin environments: <resin>, <cluster>, <host> and <web-app>. Resources configured at parent levels are shared among all children, so a database can share connection pools for all web-apps or an authenticator can provide single-signon.

The top-level <resin> tag contains any the <cluster> defined for a deployment. It also provides an environment for class-loaders, logging and shared resources.

Each <cluster> contains a set of virtual hosts served by a collection of <server>s. The cluster provides load-balancing and distributed sessions for scalability and reliability.

The <server> tag configures a JVM instance in a cluster. It configures HTTP and cluster sockets, keepalives and timeouts, thread pooling, load balancing, and JVM arguments.

The port tags configure <http> ports, addresses, cluster-ports and custom protocol TCP ports.

Describes the virtual host configuration tags.

Web applications are configured with the <web-app> tag, which can occur in a number of places.

• WEB-INF/web.xml contains a top-level web-app element. It is the Servlet standard location for defining things like servlet mappings and security roles.
• WEB-INF/resin-web.xml is also used by Resin and will override and supplement the configuration in WEB-INF/web.xml. Use it to specify Resin specific configuration if you prefer to keep WEB-INF/web.xml strictly conforming to the Servlet specification.
• A web application can also be configured in the main Resin configuration, and in this context web-app is a child of <host>.

Resin's <rewrite-dispatch> tag allows configuration for URL aliasing, rewriting, dispatching, and redirection.

<rewrite-real-path> configures an alias for files located on the filesystem.

Resin's provides web service support with <web-service> and <web-service-client> for multiple protocols: REST, SOAP, Hessian, VM.

Resin can perform access logging, specify where JDK logging interface messages go, and redirect the stderr and stdout for your applications.

Each Environment in Resin has an associated set of EL variables and functions, and Resin's configuration files support EL expressions.

Resin's configuration files support JSP EL expressions in several contexts, basic control structures for conditional processing, and several useful functions.