Choosing the Type of Enqueue Server Locking
Use this procedure to specify the type of Enqueue Server locking. The default Enqueue Server locking is Table locking.
- Open the persistent.xml
- From the right-hand pane, choose the General tab
- Choose the locking type from the following options:
- No automatic locking (except some local simulations)
This type of locking is also called Local locking. It can only be used when only one server is running because it does not synchronize the locks on multiple servers that work in a cluster. That is, Local locking synchronizes the concurrent access on one server only, and does not use the Enqueue Server to keep the locks. In this case, a container-managed bean instance can use the EJBLocking API to explicitly lock in the Enqueue Server the database entity object that the bean represents.
All container-managed entity beans from an abstract schema for which "No automatic locking" is set can access the EJBLocking object by a JNDI lookup using "java:comp/EJBLocking".
- Automatic locking
This type of locking is also called Table locking. It automatically locks the entity beans in the Enqueue Server, and in this way ensures that all applications that run in the cluster and use common data have common locks.
- Automatic locking, but tables are not defined in the Data Dictionary
This type of locking is also called Administrative locking. It is deprecated and should not be used for applications.
- No automatic locking (except some local simulations)
See also: