Message Queue 4.4 Update 1 provides a new multiplatform installer based on the pkq(5) system, also known as IPS or Image Packaging System. For information about this installer, see the Sun GlassFish Message Queue 4.4 Update 1 Installation Guide.

Message Queue 4.4 Update 1 adds a transaction persistence mechanism for file-based data stores that supports broker clusters. This mechanism provides other features as well, as described in "Optimizing File-Based Transaction Persistence" in Open Message Queue Administration Guide.

Message Queue 4.4 Update 1 supports running a broker from within a Java client. Such a broker, called an in-process or embedded broker, runs in the same JVM as the Java client that creates and starts it. For more information, see "Embedding a Message Queue Broker in a Java Client" in Open Message Queue Developer’s Guide for Java Clients.

Because the JMS specification does not define a wire protocol for communication between brokers and clients, each JMS provider (including Message Queue) has defined and uses its own propriety protocol. This situation has led to non-interoperability across JMS providers.

The JMS bridge service in Message Queue 4.4 closes this gap by enabling a Message Queue broker to map its destinations to destinations in external JMS providers. This mapping effectively allows the Message Queue broker to communicate with clients of the external JMS provider.

The JMS bridge service supports mapping destinations in external JMS providers that:

Many open source and commercial JMS providers meet these requirements, which makes the JMS bridge service an effective way to integrate Message Queue into an existing messaging environment that employs other JMS providers.

For more information about the JMS bridge service see "Configuring and Managing JMS Bridge Services" in Open Message Queue Administration Guide.

As mentioned earlier, the JMS specification does not define a wire protocol for communication between brokers and clients. The STOMP (Streaming Text Oriented Messaging Protocol) open source project at http://docs.codehaus.org/display/STOMP defines a simple wire protocol that clients written in any language can use to communicate with any messaging provider that supports the STOMP protocol.

Message Queue 4.4 provides support for the STOMP protocol through the STOMP bridge service. This service enables a Message Queue broker communicate with STOMP clients.

For more information about the STOMP bridge service see "Configuring and Managing STOMP Bridge Services" in Open Message Queue Administration Guide.

The following additional enhancements are also provided in Message Queue 4.4:

New Universal Message Service (UMS) Functions

The UMS now provides functions that use HTTP GET to offer several services:

For information about these new features, see "http://mq.java.net/4.4-content/imqums/protocol.html#Query%20and%20utility%20functions%20using%20HTTP%20GET[Query and utility functions using HTTP GET]" in http://mq.java.net/4.4-content/imqums/protocol.html.

For an overview of UMS, see Universal Message Service (UMS). For of the UMS API, see http://mq.java.net/4.4-content/imqums/protocol.html. For programming examples in several languages, see http://mq.java.net/4.4-content/imqums/examples/README.html.

IPS Package Support

Message Queue is now packaged for distribution using the open source Image Packaging System (IPS), also known as the pkg(5) system. This packaging method has been added in order for Message Queue to integrate with Sun GlassFish Enterprise Server 2.1.1.

Audit Logging Feature Reinstated

Message Queue 3.7 provided an audit logging feature that was removed in Message Queue 4.0. This feature has been reinstated in Message Queue 4.4. For information about this feature, see "Audit Logging with the Solaris BSM Audit Log" in Open Message Queue Administration Guide.

Message Queue 4.3 introduces a new universal messaging service (UMS) and messaging API that provides access to Message Queue from any http-enabled device. As a result, almost any application can communicate with any other application and benefit from the reliability and guaranteed delivery of JMS messaging. In addition, the UMS provides enhanced scalability for JMS messaging, allowing the number of messaging clients to reach internet-scale proportions.

Architecture

The basic UMS architecture is shown in the following figure:

The UMS, which runs in a web server, is language neutral and platform independent. The UMS serves as a gateway between any non-JMS client application and a JMS provider. It receives messages sent using the UMS API, transforms them into JMS messages, and produces them as persistent messages to destinations in the JMS provider by way of the provider’s native protocol. Similarly, it retrieves messages from destinations in the JMS provider in a transacted session using AUTO_ACKNOWLEDGE mode, transforms them into text or SOAP messages, and sends the messages to non-JMS clients as requested by the clients through the UMS API.

The simple, language-independent, protocol-based UMS API supports both Web-based and non-Web-based applications, and can be used with both scripting and programming languages. The API is offered in two styles: a simple messaging API that uses a Representational State Transfer (REST)-style protocol, and an XML messaging API that embeds the protocol in a SOAP message header. In both cases, however, the API requires only a single http request to send or receive a message.

The simplicity and flexibility of the UMS API means that AJAX, .NET, Python, C, Java, and many other applications can send text message and/or SOAP (with attachment) messages to JMS destinations or receive messages from JMS destinations. For example, Python applications can communicate with .NET applications, iPhone can communicate with Java applications, and so forth.

For Message Queue 4.3, the UMS supports only Message Queue as a JMS provider.

Additional Features

The UMS serves as more than the simple gateway described above. It supports stateful as well as stateless client sessions. If requested by the client, the UMS will maintain session state for the client application across multiple service requests. The UMS can use container-managed authentication, or be configured to authenticate clients with the Message Queue broker, or both. The UMS also supports transactions, enabling client applications to commit or roll back multiple service requests as a single atomic unit.

Because the UMS can support a large number of clients on a single connection to the Message Queue broker, it eases the load on the broker’s connection services, allowing for maximum scalability. In addition, UMS capacity can be increased by horizontal scaling, allowing for internet-scale messaging loads.

On the client side, because of the simplicity of the protocol-based UMS API, no client libraries are required. As a result, the API can be extended in the future to implement additional JMS features without any need to upgrade client applications.

Using the UMS

To use the UMS, you deploy the UMS into a web container that supports Servlet 2.4 or later specifications, start the Message Queue broker, create the appropriate destinations, and write a messaging application that uses the UMS API to send or receive messages.

The UMS imqums.war file, contained in the Message Queue 4.3 distribution, is installed in the following location, depending on platform:

You can rename the .war file as appropriate.

After you have deployed the imqums.war into a web container at `localhost:`port, you can find UMS at:

http://localhost:`port/imqums`

Otherwise you can find UMS as follows:

Supported Web Containers

UMS is currently supported on the following web containers:

Message Queue 4.3 provides AIX platform packages and an Installer for installing them).

The Message Queue AIX implementation supports the following software:

For installation instructions, see AIX Installation in Sun Java System Message Queue 4.3 Installation Guide.

On the AIX platform, Message Queue files are installed under a single Message Queue home directory, IMQ_HOME. IMQ_HOME denotes the directory mqInstallHome`/mq`, where mqInstallHome is the installation home directory you specify when installing the product (by default, home-directory`/MessageQueue`).

The resulting Message Queue directory structure is the same as that for the Windows platform (see the Windows section of "Distribution-Specific Locations of Message Queue Data" in Open Message Queue Administration Guide.)

Message Queue support for the AIX platform includes support for the Message Queue C-API. For instructions on building and compiling C applications on the AIX platform, see XREF.

Message Queue 4.3 introduces a new installer for Zip-based distributions, as opposed to native package distributions. The installer is used to install the new Message Queue .zip distributions for the AIX platform.

The new installer extracts Message Queue .zip files to any directory for which you have write access (you do not need root privileges) and it also enables you to register your Message Queue installation with Sun Connection.

To minimize the size of download bundles, the Java Runtime is no longer be included in the zip-based distribution (most sites will already have it). As a result, the installer command requires that a JDK or JRE be specified, either by using the JAVA_HOME environment variable or by using the -j option on the command line, as follows:

$ installer -j JDK/JRE-path

where JDK/JRE-path is the path of the specified JDK or JRE.

The following updated platform support will be certified for Message Queue 4.3:

The following additional enhancements are included in Message Queue 4.3:

New Directory Structure on Windows Platform

The installed directory structure for Message Queue on the Windows platform has been modified from previous versions to match that of the AIX platform. This directory structure will be adopted as well by the Solaris and Linux platforms in the future, to facilitate multiple installations on single computer and automatic update of Message Queue through Sun Connection, a Sun-hosted service that helps you track, organize, and maintain Sun hardware and software (see Installer Support for Sun Connection Registration).

New Broker Properties

The following new properties are available for configuring a broker:

Table 1-5 Broker Routing and Delivery Properties

JMX Administration API Enhancements

A new attribute and composite data keys have been added to the JMX API as follows:

For more information see "Message Queue MBean Reference" in Open Message Queue Developer’s Guide for JMX Clients.

Listing Durable Subscriptions for Wildcard Subscribers

The command for listing durable subscriptions:

list dur [-d topicName`]`

has been enhanced to make specification of the topic name optional. If the topic is not specified, the command lists all durable subscriptions for all topics (including those with wildcard naming conventions)

With Message Queue 4.2, a publisher can publish messages to multiple topic destinations and a subscriber can consume messages from multiple topic destinations. This capability is achieved by using a topic destination name that includes wildcard characters, representing multiple destinations. Using such symbolic names allows administrators to create additional topic destinations, as needed, consistent with the wildcard naming scheme. Publishers and subscribers automatically publish to and consume from the added destinations. (Wildcard topic subscribers are more common than publishers.)

The format of symbolic topic destination names and examples of their use is described in "Supported Topic Destination Names" in Open Message Queue Administration Guide.

This feature, introduced in Message Queue 4.2, enables validation of the content of a text (not object) XML message against an XML schema at the point the message is sent to the broker. The location of the XML schema (XSD) is specified as a property of a Message Queue destination. If no XSD location is specified, the DTD declaration within the XML document is used to perform DTD validation. (XSD validation, which includes data type and value range validation, is more rigorous than DTD validation.)

For information on the use of this feature, see "Schema Validation of XML Payload Messages" in Open Message Queue Developer’s Guide for Java Clients.

According to the X/Open distributed transaction model, support for distributed transactions relies upon a distributed transaction manager which tracks and manages operations performed by one or more resource managers. With Message Queue 4.2, the Message Queue C-API supports the XA interface (between a distributed transaction manager and Message Queue as a XA-compliant resource manager), allowing Message Queue C-API clients running in a distributed transaction processing environment (such as BEA Tuxedo) to participate in distributed transactions.

This distributed transaction support consists of the following new C-API functions (and new parameters and error codes) used to implement the XA interface specification:

If a C-client application is to be used in the context of a distributed transaction, then it must obtain a connection by using MQGetXAConnection() and create a session for producing and consuming messages by using MQCreateXASession(). The start, commit, and rollback, of any distributed transaction is managed through APIs provided by the distributed transaction manager.

For details of using the distributed transaction functions, see "Working With Distributed Transactions" in Open Message Queue Developer’s Guide for C Clients.

Message Queue 4.2 provides programming examples based on the Tuxedo transaction manager. For information on the use of these sample programs, see "Distributed Transaction Sample Programs" in Open Message Queue Developer’s Guide for C Clients.

The Message Queue installer has been enhanced to allow for registration of Message Queue with Sun Connection, a Sun-hosted service that helps you track, organize, and maintain Sun hardware and software.

As part of Message Queue installation, you can choose to register Message Queue with Sun Connection. Information about the installed Message Queue, such as the release version, host name, operating system, installation date, and other such basic information is securely transmitted to the Sun Connection database. The Sun Connection inventory service can help you organize your Sun hardware and software, while the update service can inform you of the latest available security fixes, recommended updates, and feature enhancements.

For details of registering Message Queue with Sun Connection, see Sun Java System Message Queue 4.3 Installation Guide.

Message Queue 4.2 introduced support for MySQL database as a JDBC-based data store. MySQL Cluster Edition can be used as a JDBC database for a standalone broker, and MySQL Cluster Edition can be used as the highly-available shared data store needed for an enhanced broker cluster. For information on configuring Message Queue to use MySQL, see "Configuring a JDBC-Based Data Store" in Open Message Queue Administration Guide and also "Enhanced Broker Cluster Properties" in Open Message Queue Administration Guide.

In addition to the features described above, Message Queue 4.2 included the following enhancements:

Message Queue 4.1 introduced a new, enhanced broker cluster. As compared to a conventional broker cluster, which provides only messaging service availability (if a broker fails, another broker is available to provide messaging service), the enhanced broker cluster also provides data availability (if a broker fails, its persistent messages and state data are available to another broker to use to take over message delivery).

The high-availability implementation introduced in Message Queue 4.1 uses a shared JDBC-based data store: instead of each broker in a broker cluster having its own persistent data store, all brokers in the cluster share the same JDBC-compliant database. If a particular broker fails, another broker within the cluster takes over message delivery for the failed broker. In doing so, the failover broker uses data and state information in the shared data store. Messaging clients of the failed broker reconnect to the failover broker, which provides uninterrupted messaging service.

The shared JDBC-based store used in the Message Queue 4.1 high-availability implementation must itself be highly available. If you do not have a highly available database or if uninterrupted message delivery is not important to you, you can continue to use conventional clusters, which provide service availability without data availability.

To configure a Message Queue 4.1 enhanced broker cluster, you specify the following broker properties for each broker in the cluster:

To use the enhanced broker cluster implementation, you must do the following:

For a conceptual discussion of enhanced broker clusters and how they compare to conventional clusters, see "Broker Clusters" in Open Message Queue Technical Overview. For procedural and reference information about enhanced broker clusters, see "Configuring and Managing Broker Clusters" and "Cluster Configuration Properties" in Open Message Queue Administration Guide.

If you have been using a highly available database with Message Queue 4.0 and want to switch to an enhanced broker cluster, you can use the Database Manager utility (imqdbmgr to convert to a shared persistent data store. Also see Broker Clusters for more known issues and limitations.

In addition to the file-based and LDAP-based built-in authentication mechanisms, Message Queue 4.1 introduced support for the Java Authentication and Authorization Service (JAAS), which allows you to plug an external authentication mechanism into the broker to authenticate Message Queue clients.

For a description of the information that a broker makes available to a JAAS-compliant authentication service and an explanation of how to configure the broker to use such a service, see "Using JAAS-Based Authentication" in Open Message Queue Administration Guide.

Message Queue 4.1 changed the JDBC-based data store to support enhanced broker clusters. For this reason the format of the JDBC—based data store is increased to version 410. Format versions 350, 370, and 400 are automatically migrated to the 410 version.

Please note that the format of the file-based persistent data store remains at version 370 because no changes were made to it.

The property IMQ_DEFAULT_EXT_JARS has been added to the Message Queue 4.1 environment configuration file, imqenv.conf. You can set this property to specify the path names of external .jar files to be included in CLASSPATH when the broker starts up. If you use this property to specify the location of external .jar files, you no longer need to copy these files to the lib/ext directory. External .jar files can refer to JDBC drivers or to JAAS login modules. The following sample poperty, specifies the location of JDBC drivers.

Message Queue 4.1 introduced support for the Sun Java Enterprise System (Java ES) Monitoring Framework, which allows Java ES components to be monitored using a common graphical interface. This interface is implemented by a web-based console called the Sun Java System Monitoring Console. Administrators can use the Console to view performance statistics, reate rules for automatic monitoring, and acknowledge alarms. If you are running Message Queue along with other Java ES components, you might find it more convenient to use a single interface to manage all of them.

For information on using the Java ES monitoring framework to monitor Message Queue, see XREF.

Previously, only transactions in a PREPARED state were allowed to be rolled back administratively. That is, if a session that was part of a distributed transaction did not terminate gracefully, the transaction remained in a state that could not be cleaned up by an administrator. In Message Queue 4.1, you can now use the Command utility (imqcmd) to clean up (roll back) transactions that are in the following states: STARTED, FAILED, INCOMPLETE, COMPLETE, and PREPARED.

To help you determine whether a particular transaction can be rolled back (especially when it is not in a PREPARED state), the Command utility provides additional data as part of the`imqcmd query txn` output: it provides the connection id for the connection that started the transaction and specifies the time when the transaction was created. Using this information, an administrator can decide whether the transaction needs to be rolled back. In general, the administrator should avoid rolling back a transaction prematurely.

In Message Queue 4.1, C clients, like Java clients, can now connect to a fixed broker port rather than to a port dynamically assigned by the broker’s Port Mapper service. Fixed port connections are useful if you’re trying to get through a firewall or if you need to bypass the Port Mapper service for some other reason.

To configure a fixed port connection you need to configure both the broker and the C client run time (both ends of the connection). For example, if you want to connect your client via ssljms to port 1756, you would do the following:

A new API was added in Message Queue 4.0 for configuring and monitoring Message Queue brokers in conformance with the Java Management Extensions (JMX) specification. Using this API, you can configure and monitor broker functions programmatically from within a Java application. In earlier versions of Message Queue, these functions were accessible only from the command line administration utilities or the Administration Console.

For more information see the Open Message Queue Developer’s Guide for JMX Clients.

Message Queue 4.0 introduced support for client runtime logging of connection and session-related events.

Fore information regarding client runtime logging and how to configure it, see the Java Dev Guide pag 137.

Message Queue 4.0 introduced an event notification API that allows the client runtime to inform an application about changes in connection state. Connection event notifications allow a Message Queue client to listen for closure and re-connection events and to take appropriate action based on the notification type and the connection state. For example, when a failover occurs and the client is reconnected to another broker, an application might want to clean up its transaction state and proceed with a new transaction.

For information about connection events and how to create an event listener, see the Java Dev Guide, page 96.

In Message Queue 4.0, a new subcommand and several command options were added to the Command utility (imqcmd) to allow administrators to quiesce a broker, to shutdown a broker after a specified interval, to destroy a connection, or to set java system properties (for example, connection related properties).

For complete information about the syntax of the imqcmd command, see "Command Line Reference" in Open Message Queue Administration Guide.

In Message Queue 4.0 a new query subcommand was added to the Database Manager utility, imqdbmgr. This subcommand is used to display information about a JDBC-based data store, including the database version, the database user, and whether the database tables have been created.

The following is an example of the information displayed by the command.

In Message Queue 4.0, Apache Derby Version 10.1.1 is now supported as a JDBC-based data store provider.

Message Queue 4.0 introduced changes to the JDBC-based data store for optimization and to support future enhancements. For this reason the format of the JDBC-based data store was increased to version 400. Note that in Message Queue 4.0, the file-based data store version remains 370 because no changes were made to it.

Message Queue 4.0 added two new properties which are set on all messages that are placed in the dead message queue.

Starting with Message Queue 4.0, the default value for the client connection factory property imqSSLIsHostTrusted is false. If your application depends on the prior default value of true, you need to reconfigure and to set the property explicitly to true.

You might choose to trust the host when the broker is configured to use self-signed certificates. In this case, in addition to specifying that the connection should use an SSL-based connection service (using the imqConnectionType property), you should set the imqSSLIsHostTrusted property to true.

For example, to run client applications securely when the broker uses self-signed certificates, use a command like the following.

To use the Command utility (imqcmd) securely when the broker uses self-signed certificates, use a command like the following (for listing connector services).