Running coexisting application servers
You can create an environment that has coexisting product installations, which means you run multiple independent WebSphere® Application Server installations and multiple nodes on the same system at the same time. The installations can be the same version or different versions, and you can choose whether they share a single web server installation. A major consideration in coexistence is the avoidance of port conflicts.
About this task
All combinations of WebSphere Application Server versions and editions can coexist so long as there are no port conflicts. For example, you can run a WebSphere Application Server (base) Version 8.5 installation and a WebSphere Application Server Network Deployment Version 9.0 installation on the same system if all of the ports are unique.
Clone migration will address many of the naming issues to ensure that the old and new cells can coexist. Ports, cell, node, server, and cluster short names, and procedure names will be different between the old and new cells so that both may run independently.
If you want to install multiple instances of the same product version on a system, consider creating multiple profiles instead. One of the main goals of multiple-profile support is to minimize the need for having coexisting installations of the same product version. One reason that you might want to install coexisting instances of WebSphere Application Server Version 9.0 is a need to have different fix levels of the product on a single machine.
The system where you install multiple product versions or editions must meet all of the installation prerequisites for all of the products, such as the minimum Java and operating system requirements. For information about these requirements, see WebSphere Application Server detailed system requirements.
| Coexistence type | Comments |
|---|---|
| General | Multiple WebSphere Application Server for z/OS cells can coexist in the same sysplex. Multiple WebSphere Application Server for z/OS nodes can coexist on the same LPAR. WebSphere Application Server for z/OS Version 7.0 or later can coexist in the same cell with Version 9.0 nodes. No two cells can have the same cell short name. Separate cells need separate configuration file system mount points and Job Control Language (JCL) procedures. You need to determine port conflicts that might occur when earlier versions coexist with Version 9.0. For default port information, see Default port assignments. |
| WebSphere Application Server for z/OS Version 7.0 or later and Version 9.0 | Nodes can coexist on the same LPAR in the same cell or in different cells. |
You can resolve conflicting port assignments by specifying port assignments for coexistence during profile creation, by wsadmin scripting, or by using the administrative console page to ensure that WebSphere Application Server Version 9.0 can run with an earlier version. For more information about wsadmin scripting, see wsadmin scripting tool.