WAS v8.0 > Migration and coexistence > Distributed operating systems > Run multiple application server versions
Coexistence support
Coexistence is a state in which multiple installations and multiple nodes from different versions of WAS run independently in the same environment at the same time.
As it applies to WAS products, coexistence primarily refers to the ability of multiple installations of WAS to run independently on the same machine at the same time. Multiple installations include multiple versions and multiple instances of one version. Coexistence also implies various combinations of web server interaction.
WAS WAS v8s can coexist with the following supported versions:
- WAS Version 6.x
- WAS ND Version 6.x
All combinations of v6.x, Version 7.0, and WAS v8s can coexist so long as there are no port conflicts.
WAS Version 6.x and 7.0 clients can coexist with v8.0 clients.
If you neither migrate nor coexist with an earlier version of WAS, you are choosing to ignore the previous installation and you can run only one version at a time because of conflicting default port assignments. It is possible for both versions to run at the same time without conflict if you use non-default ports in one version.
To set up coexistence with WASv6.x or 7.x, ensure that unique ports are selected during profile creation for the v8.0 installation. To set up coexistence with an existing installation of v8.0, select the Install a new copy of the V80 Application Server product radio button during installation.
We 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 WAS v8.0 can run with an earlier version. Read the "Wsadmin tool" article in the information center for more information on wsadmin scripting.
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
- DRS client address (Deprecated)
- SAS SSL ServerAuth listener address
- 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
Installed product WAS v8.0 clients WAS v6.x Supported WAS WAS ND v6.x Supported WAS v7.0 Supported WAS WAS ND v7.0 Supported WASVersion 6.x and 7.0 products can coexist with WAS v8s.
Installed product WAS v6.x v7.0 WAS v8.0
Application Server WAS ND WAS, Express Application Server WAS ND WAS, Express WAS v6.x Supported Supported Supported Supported Supported Supported WAS ND v6.x Supported Supported Supported Supported Supported Supported WAS v7.0 Supported Supported Supported Supported Supported Supported WAS ND v7.0 Supported Supported Supported Supported Supported Supported WAS v8 Supported Supported Supported Supported Supported Supported WAS ND v8.0 Supported Supported Supported Supported Supported Supported In addition to multiversion coexistence, WAS also lets you install multiple times on one machine (multiple installation instances) or install once and have multiple profiles. Multiple v8.0 installation instances on one machine include the following combinations:
- Multiple application server profiles from multiple installations of the WAS product
- Multiple application server profiles from a single installation of the WASr product
Set up v6.x, v7.0 and v8.0 coexistence
Set up v8.0 coexistence
Run multiple application server versions