Features that can be used only with the primary installation on Windows

Some Windows operating-system features can be used only with the primary installation. This restriction is due to the central registration of interface libraries, which might conflict as a result of multiple versions of IBM® WebSphere® MQ being installed.

The .NET monitor

The IBM WebSphere MQ .NET monitor can run in two different modes: transactional and non-transactional. The transactional mode uses MSDTC transaction coordination and requires that the .NET monitor is registered with COM+. The .NET monitor from the primary installation is the only .NET monitor that is registered with COM+.

Any attempt to run the .NET monitor in transactional mode with a non-primary installation results in the failure of the .NET monitor to enlist with MSDTC. The .NET monitor receives an MQRC_INSTALLATION_MISMATCH error, which in turn results in an AMQ8377 error message on the console.

COM/ActiveX interface classes

The COM/ActiveX interface classes are registered only for the primary installation. If there is an installation of IBM WebSphere MQ Version 7.0.1 on the system, the COM/ActiveX interface classes registered are not capable of connecting to queue managers running under other installations. If the primary installation is an installation of IBM WebSphere MQ Version 7.1 or later, the interface classes can connect to queue managers associated with any installation. Server COM/ActiveX applications are limited by this restriction, but client applications can connect to any queue manager.

Any attempt to start a COM/ActiveX application that uses libraries from installations other than the primary installation results in failure with an MQRC_Q_MGR_NOT_AVAILABLE error.