Overview

The HTTP transport uses the Jetty HTTP server, a high quality server used in many high-profile open-source and commercial software platforms. Jetty may be used as the primary HTTP server for an application or it may be configured as a pass-through server behind Apache either by using proxy mapping or the mod_jk protocol. Detailed information about Jetty configuration is available on the the Jetty web site.

HTTPHandler

NetKernel's Jetty HTTP handler is org.ten60.transport.jetty.HTTPHandler which is configured to serve the entire root '/' context by default.

HTTPHandler maps all HTTP requests to NetKernel root requests. It issues the root request into the internal address space of the Fulcrum module which hosts the transport. The root request include an argument with the representation type IAspectHTTPRequestResponse which is a wrapper class for both the Jetty HttpRequest and HttpResponse objects.

While it is possible to write applications that interact direct with the HTTP request and response streams, it is generally more practical to configure the fulcrum to route the root request issued by the HTTP Transport request to the HTTP Bridge Accessor for post-processing.

Configuration

The HTTP Transport requests its configuration from the resource located at the URI address ffcpl:/etc/TransportJettyConfig.xml.

The JettyTransport uses Jetty's declarative XML configuration model. The config document has a <httpConfig> root element which may contain multiple Jetty style <Configure> blocks. Each of these will be processed and registered as a Server. A detailed guide to Jetty configuration and the XML configuration model is available here

You can examine the configuration file for the front-end fulcrum HTTP transport in [install]/modules/front-end-fulcrum/etc/, which starts an HTTP transport on port 8080.

Non-Blocking IO

Jetty supports an experimental ChannelListener that uses JDK 1.4.1 NIO non-blocking IO. NIO allows a much reduced thread count and higher performance. By default we have chosen the stable SocketListener with configurable thread group properties. An example configuration for the ChannelListener is provided and may be experimented with. Future versions of Jetty will support NIO by default.

Security - Access Control

Access control can be considered in two stages. A first stage is to apply request filters in a chain on the input stage to the JettyTransport. By default the JettyTransport does not make any security decision for a request. Optional File, IP and Path filters can be added and are available in the org/ten60/transport/jetty/ package. The Jetty website provides details of how Jetty can be configured with input chain filters.

A second more comprehensive stage is to consider a policy firewall for your application. Please see the security guide for details.

SSL

Jetty can be readily configured to support SSL - an example configuration is given in the config.xml file. A detailed discussion and guide to SSL configuration is provided here