Configuring Multiple InterSystems IRIS Instances
You can install and simultaneously run multiple instances on a single machine. To do so, install InterSystems IRIS as for a single installation, giving each instance a unique name, a unique installation directory, and a unique port number.
Please refer to the Multiple InterSystems IRIS Instances section of the System Administration Guide for more detailed information.
There are additional considerations for configuring access to applications when running multiple instances. For details on this, see Access Applications on Multiple InterSystems IRIS Servers.
The installer automatically configures URLs with root-level application paths to route toward the instance it is currently installing for the convenience of users who only need one InterSystems IRIS instance installed at a time, and who therefore do not need to specify an instance name in the URL.
However, this means that if you have a system with multiple instances configured and you uninstall the most recently configured instance, requests to root-level application paths no longer succeed. You must manually update the Web Gateway application access profiles for the / (root) and /csp paths to direct requests to a default application server other than the one which you have uninstalled. You can then remove the obsolete server access profile for that instance.