Introduction

The Novell exteNd Messaging Platform JMS server is a 100% pure Java implementation of the Java Messaging Service (JMS) API based on high performance and scalable enterprise class IIOP support in the Novell exteNd Messaging Platform ORB. The JMS server is fully compliant with the JMS specification v1.1 It implements all features of the specification, including:

Point-to-point (P2P) and Publish/Subscribe (pub/sub) messaging models.
Automatic, client-initiated, lazy, or transactional acknowledgement modes.
Transient messages for performance, and persistent messages for guaranteed delivery.
Application Server Facilities (concurrent message processing using connection consumers).
Transactional messaging; sending and receiving message can participate in a distributed transaction.

Also, the JMS server supports several value-added features:

Clustering for fault-tolerance and replication of destinations
Memory management for paging out infrequently used messages
HTTP client connectivity using the ORB's HTTP tunnel
Sits on top of proven, high-performance IIOP engine
Built-in system namespace (CosNaming service)
Security (authentication and access control)
Administration API's and tools
Ability to run the JMS server in-process
Server monitor process for automatic restart

The JMS server is built on top of the ORB, which is a fully CORBA 2.4 compliant Object Request Broker (ORB). The Novell exteNd Messaging Platform ORB is an enterprise-class, high performance, and scalable Java CORBA ORB runtime, which includes services, and development tools. Features supported include:

Forward (IDL to Java) and reverse (Java RMI to IIOP, and Java RMI to IDL) compilers
Portable Object Adapter (POA)
Multiple profile IOR's for clustering
Objects by Value
Server Activation
IIOP Connection Concentrator
Pluggable Authentication support
IIOP/SSL, and HTTP tunneling
COS Name Service
Multicast Object Invocations
Object Transaction Service pluggability

The ORB provides the JMS server with a proven mechanism for transmitting messages between JMS applications. Messages are therefore sent using the IIOP protocol, and the ORB provides the management of socket connections. Also, the JMS server utilizes the authentication support from the ORB.

The Novell exteNd Messaging Platform's JMS is a server-based JMS implementation, which means that a message server must be started before any client applications can exchange messages. The JMS server server can be running on any host accessible to clients, and the server's responsibility is to receive messages from producers, filter them according to message selectors, store into a persistent store if necessary, and finally disseminate messages to consumers.

The JMS server has supported clustering since version 2.0. This enables multiple JMS servers to cooperate in getting messages from producer applications to consumer applications. Clustering makes it easier to write applications that have better scalability and are less sensitive to partial system failures.

The JMS server implements a CORBA COS namespace, which is accessible via the JNDI/CosNaming driver. This namespace contains the connection factories, as well as all the destinations served by the JMS server. A proprietary API for easy access to administered object is also provided.

The JMS server provides support for authentication, and access control. The users are authenticated when they create a JMS connection. Access control is done when the producers, consumers, and queue browsers are created on the connection, as well as when an administration function of the JMS server is accessed. Also, SSL is supported for integrity and confidentiality protection of the communication between client and server.