Single installation of Version 7.1, or later, configured as non-primary

If you install IBM® WebSphere MQ Version 7.1, or later, as non-primary you might have to configure a library path for applications to load IBM MQ libraries. On Windows, some product capabilities are available only when IBM MQ is configured as primary.

UNIX and Linux systems

The implications of running a non-primary installation on UNIX and Linux are:

• Applications that locate their IBM MQ libraries using an embedded library path, for example, RPATH, cannot find those libraries if the following conditions are true:
  • IBM MQ is installed in a different directory from the directory specified in the RPATH
  • There are no symbolic links in /usr
• Where applications locate their libraries using an external library path, for example, LD_LIBRARY_PATH, you must configure the external library path to include the MQ_INSTALLATION_PATH/lib or MQ_INSTALLATION_PATH/lib64 directory. The setmqenv and crtmqenv commands can configure a number of environment variables in the current shell, including the external library path.
• Most IBM MQ processes run as setuid/setgid. As a result, when loading user exits they ignore the external library path. User exits that reference IBM MQ libraries can find those libraries only if they are found in the library path embedded within them. They would be resolved if there were a symbolic link in /usr. User exits that are intended to be run on IBM WebSphere MQ Version 7.1, or later can now be built so that they do not refer to IBM MQ libraries at all. Instead they rely on IBM MQ to pass in function pointers to the IBM MQ functions that the exit can then use. For more information, see Writing exits and installable services on UNIX, Linux, and Windows .

For more information about options for connecting our applications, see Connecting applications in a multiple installation environment. On UNIX and Linux platforms, the first installation onto a system is not automatically configured as the primary installation. However, a single symbolic link is included in /usr/bin to locate the dspmqver command. If we do not want any symbolic links, you must remove this link using the following command:

setmqinst -x -p MQ_INSTALLATION_PATH

Windows systems

The implications of running a non-primary installation on Windows are:

• Applications normally find their libraries using the external library path, PATH. There is no concept of an embedded library path or explicit library location. If the installation is non-primary, the global PATH environment variable does not contain the IBM MQ installation directory. For applications to find IBM MQ libraries, update the PATH environment variable to reference the IBM MQ installation directory. The setmqenv and crtmqenv commands can configure a number of environment variables in the current shell, including the external library path.
• Some product capabilities are available only when an installation is configured as the primary installation; see Features that can be used only with the primary installation on Windows .

By default, on Windows, the first installation is automatically configured as primary. You must manually deselect it as the primary installation.