I don't know a design pattern especially for this issue.
You can serialize the object on disk or in db using Read/write lock pattern(java provides an interface for that java.util.concurrent.locks.ReadWriteLock). Each time a JVM needs its data will load it if was changed by another thread. You can also take a look on some design patterns you might use: Semaphor and Mutex.
If you want to avoid using the disk or the db, you can use one jvm as a master and keep the object and to distribute to other jvm instances.
Comments
You can serialize the object on disk or in db using Read/write lock pattern(java provides an interface for that java.util.concurrent.locks.ReadWriteLock). Each time a JVM needs its data will load it if was changed by another thread. You can also take a look on some design patterns you might use: Semaphor and Mutex.
If you want to avoid using the disk or the db, you can use one jvm as a master and keep the object and to distribute to other jvm instances.