This bean container has no other interest than SIMULATING a "cluster" configuration
with several jonas server running the same entity beans backed on a unique database.
All entity beans must have the "shared" flag set.
Isolation level should be set to "Serialized" on the database.
All operations accessing fields that can be modified must have the "Required" 
transaction attribute, even if operation don't modify this field.
This is to be sure that the bean state is read again if another process has modified it.
