IBM User Guide for Java V7 on Windows > Troubleshooting and support > Using diagnostic tools > Shared classes diagnostic data > Deploying shared classes

Cache naming

If multiple users will be using an application that is sharing classes or multiple applications are sharing the same cache, knowing how to name caches appropriately is important. The ultimate goal is to have the smallest number of caches possible, while maintaining secure access to the class data and allowing as many applications and users as possible to share the same classes.

To use a cache for a specific application, write the cache into the application installation directory, or a directory within that directory, using the -Xshareclasses:cachedir=<dir> suboption. This helps prevent users of other applications from accidentally using the same cache, and automatically removes the cache if the application is uninstalled. If the directory does not exist it is created.

If the same user will always be using the same application, either use the default cache name (which includes the user name) or specify a cache name specific to the application. The user name can be incorporated into a cache name using the %u modifier, which causes each user running the application to get a separate cache.

Multiple applications or different JVM installations can share the same cache provided that the JVM installations are of the same service release level. It is possible for different JVM service releases to share the same cache, but it is not advised. The JVM will attempt to destroy and re-create a cache created by a different service release. See Compatibility between service releases for more information.

Small applications that load small numbers of application classes should all try to share the same cache, because they will still be able to share bootstrap classes. For large applications that contain completely different classes, it might be more sensible for them to have a class cache each, because there will be few common classes and it is then easier to selectively clean up caches that aren't being used.

On Windows, caches are stored as memory-mapped files in the user's directory in Documents and Settings. Therefore, one user creating a cache named myCache and another user creating a cache named myCache will cause two different caches named myCache to be created.

Parent: Deploying shared classes

Error 404 - Not Found

The document you are looking for may have been removed or re-named. Please contact the web site owner for further assistance.