問87
頻出度★★☆
通常使用される主系と, その主系の故障に備えて待機しつつ他の処理を実行している従系の二つから構成されるコンピュータシステムはどれか。
平成29年度 秋期 ITパスポート試験 問87
テクノロジ系システム構成要素 › システムの構成
This question's explanation and your answers so far.
解説
問 87
Incorrectア
A client-server system is a processing form that divides roles between clients that request services and servers that provide them; it is not a two-part failure-countermeasure structure of a primary and a secondary system. It is not about a standby system for availability, so it is wrong.
Incorrectイ
A dual system is a method in which two systems always run the same processing in parallel and improve reliability by cross-checking their results. Rather than one side standing by to perform other processing, both systems run the same processing, which differs from the question, so it is wrong.
- ウ
正解 The correct answer is “ウ Duplex system”. A duplex system has a two-part structure for improving availability: a primary system (active system) that handles normal operation, and a secondary system (standby system) prepared for the primary system’s failure. As the question states, the secondary system stands by while normally running other processing (such as batch processing), and when the primary system fails it stops that processing and takes over the primary system’s role. This description of “a primary and a secondary system” and “running other processing while standing by” matches the definition of a duplex system, so ウ is correct.
Incorrectエ
A peer-to-peer system is a network form in which each computer provides services to the others on an equal footing. It is not a structure premised on a master-slave relationship of primary and secondary systems or on switchover at the time of failure, so it is wrong.
ここがポイント
- Duplex system = a two-part structure of a primary system (active system) and a secondary system (standby system); the secondary normally runs other processing and takes over when the primary fails, an availability-improving method.
- Distinction from a dual system = a dual system runs the same processing in parallel on both systems and checks the results, which differs from a duplex system whose standby system performs other processing.
用語