IPA IP 2023 Question 70

Clustering — several computers are linked to run as one system, sharing the load and standing in for each other.

In a cluster, multiple servers (nodes) work together and appear to users as a single computer. For a web service this gives both things the question asks for:

• •Volume: a load balancer spreads the incoming accesses across the nodes, so adding nodes adds capacity
• •Reliability: if one node fails, the others carry on the service (failover)

Answer (a)

Why not others:

• •(b) Spooling — output for a slow device such as a printer is first written to disk, so the CPU can go on without waiting; it concerns one computer and its peripherals
• •(c) Buffering — data is held for a while in a memory area to absorb a difference in speed or timing between two devices or processes
• •(d) Mirroring — the same data is written to two disks (RAID 1) or two sites at once, so a copy survives a failure; it duplicates data, it does not make computers act as one

Key rule: Clustering joins computers into one system for capacity and availability; mirroring duplicates data; spooling and buffering smooth out speed differences in moving data.

System Component · AI-written, may contain errors