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.

Table 1. Things to consider when deciding to set up coexistence
Reasons to set up coexistence Reasons to not set up coexistence
  • You can achieve complete isolation between each WebSphere Application Server instance. You can uninstall one instance independently of the others.
  • You can install the WebSphere Application Server (base) more than once on the same machine.
  • You can install the WebSphere Application Server Network Deployment Version 7.0 or later product and the Version 9.0 product on the same machine.
  • The machine might have a hard disk space constraint.
  • You can use the operating system registry to locate the last installed instance of a WebSphere Application Server only.

    When you install any product a second time, the last installation is the one that is displayed in the registry.

  • Uninstalling the last instance removes any record of the product in the registry.

    Suppose that you installed three instances of WebSphere Application Server (base). You use the remove program function of the operating system to uninstall the registered third copy of the base product. A registry record no longer exists that indicates the existence of the other two installation instances. Other applications cannot use a query of the operating system registry to detect the presence of either WebSphere Application Server (base) product instance.

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.

You can resolve conflicting port assignments by specifying port assignments for coexistence during profile creation, by wsadmin scripting, or by using the Servers > Application Servers > server1 > Ports 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.

Coexistence processing changes the following configuration files:
  • virtualhosts.xml
    • HTTP transport port
    • IBM® HTTP server port
    • HTTPS transport port
    • HTTP administrative console port
    • HTTPS administrative console secure port
  • serverindex.xml
    • Bootstrap address
    • SOAP connector address
    • Data Replication Service (DRS) client address
      Deprecated feature: This port is deprecated and is no longer used in the current version of WebSphere Application Server.
    • Secure Authentication Service (SAS) Secure Sockets Layer (SSL) ServerAuth listener address
    • Common Secure Interoperability Protocol Version 2 (CSIV2) SSL ServerAuth listener address
    • CSIV2 SSL MutualAuth listener address
    • Administrative console port
    • HTTP transport port
    • Distribution and Consistency Services (DCS) unicast address
    • Administrative console secure port
    • HTTP transport secure port
    • Service Integration Bus (SIB) endpoint address
    • SIB endpoint secure address
    • SIB MQ endpoint address
    • SIB MQ endpoint secure address

For more information, see Port number settings.

Procedure

Install multiple instances of the product on a system. Be careful to avoid port conflicts, and optionally set up a shared web server. For more information, see Setting up coexisting product installations.