Choosing the Appropriate Components for Your Operating System

Silk Central 19.5 or later internally uses the libraries of the AdoptOpenJDK instead of the Oracle JRE. This change affects all servers, which means the application server, the front-end servers, the chart server, and the execution server, as well as the communication and interaction between all servers.

There is no dependency between any installed JRE and the internally used JRE libraries, except if you require an execution server to run in 32bit mode. To start the execution server in this case, you need to use the Execution Server Launcher or the Execution Server Package and your own installed 32bit JRE. By default, execution servers are running in 64bit mode.

For the front-end server, the chart server, and the application server, the following rules apply with Silk Central 19.5 or later:

New instances of these servers are always 64bit.
The default instance (silk) that is created with a new installation of Silk Central is always 64bit.
As long as an existing 32bit instance is not upgraded, it remains a 32bit instance.
Applying a hotfix to an existing 32bit instance does not change the bitness to 64bit. The instance remains a 32bit instance.
Upgrading an existing 32bit instance to Silk Central 19.5 or later automatically converts it to a 64bit instance.

The following rules apply for the execution of Silk Performer 19.5 or later with Silk Central 19.5 or later:

Silk Performer 19.5 or later includes a separate JRE for the Silk Performer execution.
To execute Silk Performer by using a different JRE than the one that is shipped with Silk Performer, add the path to the JRE as a JREPath tag to the SccLtcVersionsConf.xml file. For example:
```
<JREPath>C:\Program Files (x86)\Java\MyJre8.0</JREPath>
```
Note: The JRE specified in the JREPath tag must be a 32bit JRE.
The full path of the JREPath tag in the SccLtcVersionsConf.xml file is CoreVersions > Entry > JREPath.
When using the Execution Server Launcher for Silk Performer execution, Silk Performer 19.5 must be installed in the default directory C:\Program Files (x86)\Silk\Silk Performer 19.5. Changes to the SccLtcVersionsConf.xml file are overwritten by the Execution Server Launcher on each execution server restart.