layout: default_md title: ActiveMQ 4.0 Release title-class: page-title-activemq5 type: activemq5

Overview > Download > ActiveMQ 3.2.1 Release

New and Noteworthy

This is the 4.0 release of Apache ActiveMQ. This release of Apache ActiveMQ includes a large number of [new features](New FeaturesFeatures/New Features/Features/New Features/changes-in-40) such as MasterSlave and [Message Groups](Consumer FeaturesFeatures/Consumer Features/Features/Consumer Features/message-groups) together with numerous bug fixes.

Warnings

When upgrading from a previous release you are advised to clear down the journal files and persistent database first before upgrading to this jar as the binary format of messages is not compatible with 3.x or earlier 4.0 milestone releases.

Known issues

Some folks have found issues with acknowledgements, particularly when using auto-ack mode. This has been fixed in 4.0.1 which will be released shortly. Until then we recommend you disable optimizeAcknowledge. e.g. connect via

tcp://localhost:61616?jms.optimizeAcknowledge=false

The source distributions do not build as is anymore due to changes in the way the maven repo is now setup at Apache. You must first apply the following patch before doing the build. You will need to download the patch and apply it using the patch command.

cd ${path-to-activemq-source-distro}
patch -p 0 < ${path-to-amq4-build.patch}

What has changed

The 4.x branch of Apache ActiveMQ has now moved to the Apache Incubator so the package names have changed from org.activemq to org.apache.activemq. For a full list see the [Changes in 4.0](New FeaturesFeatures/New Features/Features/New Features/changes-in-40).

Download Here

DownloadDescription
incubator-activemq-4.0.zipBinary Distribution in zip package
incubator-activemq-4.0-src.zipSource Distribution in zip package
incubator-activemq-4.0.tar.gzBinary Distribution in gz package
incubator-activemq-4.0-src.tar.gzSource Distribution in gz package

SVN Tag Checkout

svn co https://svn.apache.org/repos/asf/incubator/activemq/tags/activemq-4.0

Changelog

For a more detailed view of new features and bug fixes, see the release notes

Also see the previous ActiveMQ 4.0 RC2 Release