In distributed systems, link and site failure is detected by . . . . . . . .

Solution (By Examveda Team)

Option A: Polling refers to a mechanism where a central node periodically checks other nodes to see if they are functioning properly. While this can detect failure, it is not the most efficient or commonly used method in distributed systems for detecting link and site failures.

Option B: Handshaking is a method where two nodes communicate with each other to confirm the status of the connection. In distributed systems, handshaking is a more common way of detecting failures because it allows both ends of the communication to verify the connection is still active, making it effective for detecting link and site failures.

Option C: Token Passing is typically used in network protocols where nodes pass a token to each other to control access to a shared resource. While token passing ensures proper coordination between nodes, it is not primarily used for failure detection in distributed systems.

Option D: None of the mentioned is incorrect, as both polling and handshaking could be used for failure detection, but handshaking is the most suitable answer for distributed systems.

Conclusion: The correct answer is Option B: Handshaking, as it is the most reliable and commonly used method in distributed systems for detecting link and site failures.