The Lock Server is not a Database Administrator tool. It is an Objectivity program that is used by the DeltaV system.
The Lock Server is an Objectivity control for assigning locks on transactions and applications. This function is designed to track which workstation or node is currently in control of the data. Locking out other workstations and nodes keeps multiple workstations from making changes to the same data at the same time. This ensures data integrity in your database.
Transaction locks
A transaction lock occurs when a node accesses the database and effects a change on that database. A change on the database can be any update, node removals, device configuration changes, addition of a control loop, or other configuration changes. While that change is occurring the Objectivity Lock Server applies a lock on the data until that transaction is complete. No other node can change the data at this time. Other nodes can utilize (read) the data, but not change (write) it. This is called MROW - Multiple Reads One Write.
Application locks
An application lock is applied when a node has the application in use. This prevents other nodes from accessing that application and making simultaneous changes through the application. Locking an application ensures configuration integrity. When that node (workstation or device) is finished with the application, the lock is released and other nodes can now use the application.
An application lock is invalid when any part of the system (node or host computer) is interrupted before the lock is cleared. The lock remains even though the node is no longer using the application. This prevents other nodes from accessing the same application.
At startup, the Database Server reads what the Lock Server is doing to determine if any locks are currently applied to a transaction or application. These locks are different than the DeltaV security locks. The Lock Server locks are specific to database functions and are not related to user access and security. The Database Server attempts to clear any locks it detects at startup.
The DeltaV Monitor tools require that the Objectivity Lock Server be properly configured and running. You can verify the correct version and setup of the Lock Server in .
The Lock Server should reside on the host machine along with the Federated database (configdb.hdb.FDB), the Boot file related to the Federated database (configdb.hdb) and the data files that make up the DeltaV control database. This is the default download.
If the system is interrupted (for example, powered off) before the transaction is complete, then the transaction lock remains but is not attached to a specific node. This results in an invalid (unfinished) transaction lock.