Web Server Agents

The Web Agents represent a set of agents that cooperate to implement the functionality of a typical web server. Because each significant feature is implemented as an agent, only the required functionality needs to be loaded for a specific application. This keeps things lightweight and extensible, as existing components can also be replaced by others with enhanced functionality.

These Web Agents pass HTTP request information to Request Agents which can be extended to generate dynamic content for HTML, WAP, or even XML applications. The Web Server agent itself can be easily extended to support SSL using third party encryption libraries.

Supported Features

• Customizable Request Agents (Easier than servlets!)
• File Serving
• Server Redirection
• Proxying
• Client Authentication
• Supports WAP and XML
• Multihoming
• Access Logging
• Web-based Use Statistics
• Sessions (Using Session Manager)
• Cookies
• Easily Extended To Use a SSL Socket Library

The following diagram illustrates the Web Agents including theKernel Agents they rely upon.Request Agent is extended to handle HTTP based Agent Requests to provide dynamic content generation. These Web Request Agents register themselves to handle specific URLs (like a CGI script) and wait for the next request to handle content generation for that URL from the Web Server.

Note: In this diagram, involvement of the Service Manager is implied but not drawn. The Service Manager is the center of the Web Agent programming.

Web Server Agents and Their Relationships

The WebServer agent listens to a socket and spawns connection handlers to deal with each incoming connection. The WebServer agent also provides a few basic HTTP features like returning ERROR code responses, certain security functions, and determining MIME types of the data served. The connection handler (com.cometway.http.ConnectionKMethod) looks at the Agent Kernel's ServiceManager for agents to handle the incoming requests. The basic web server functionality is embodied in the agents provided in Comet Way's HTTP Package, which will register with the service manager to handle most incoming requests. The following sections describe these agents and how to set them up.