Handling Server Failure with Idempotent Operations
This lesson describes how the idempotency of the NFSv2 operations helps it handle failures.
We'll cover the following...
Server failures
When a client sends a message to the server, it sometimes does not receive a reply. There are many possible reasons for this failure to respond. In some cases, the message may be dropped by the network; networks do lose messages, and thus either the request or the reply could be lost and thus the client would never receive a response.
It is also possible that the server has crashed, and thus is not currently responding to messages. After a bit, the server will be rebooted and start running again, but in the meanwhile, all requests have been lost. In all of these cases, clients are left with a question: what should they do when the server does not reply in a timely manner?
In NFSv2, a client handles all ...