Network lock manager architecture

The network lock manager contains both server and client functions.

The client functions are responsible for processing requests from the applications and sending requests to the network lock manager at the server. The server functions are responsible for accepting lock requests from clients and generating the appropriate locking calls at the server. The server will then respond to the locking request of the client.

In contrast to NFS, which is stateless, the network lock manager has an implicit state. In other words, the network lock manager must remember whether the client currently has a lock. The network status monitor, rpc.statd, implements a simple protocol that allows the network lock manager to monitor the status of other machines on the network. By having accurate status information, the network lock manager can maintain a consistent state within the stateless NFS environment.