1Z0-068 · Question #158
Which three statements define a cluster?
The correct answer is A. is a group of independent, but interconnected computers that act as a single system B. can be deployed to increase availability and performance C. can be deployed to balance a dynamically changing workload. See the full explanation below for the reasoning.
Question
Which three statements define a cluster?
Options
- Ais a group of independent, but interconnected computers that act as a single system
- Bcan be deployed to increase availability and performance
- Ccan be deployed to balance a dynamically changing workload
- Dshould appear to an application as multiple servers
How the community answered
(45 responses)- A73% (33)
- D27% (12)
Community Discussion
6
Prof. SaraFeb 8, 2026The correct answers are A, B, C, and if you miss this one on exam day it is usually because option D sneaks past you. A cluster is defined precisely by the illusion of unity: independent nodes that interconnect and present themselves to an application as one system, not as multiple servers, which is exactly why D is the trap answer and the wrong one. The whole point of clustering in the Oracle RAC context, which maps squarely to the High Availability and Grid Infrastructure domains on the 1Z0-068 blueprint, is that the application sees a single logical system even though the physical layer has many nodes. B and C round out the definition by naming the two payoffs you buy with that architecture: you deploy a cluster for availability (surviving node failures without downtime) and for performance through workload balancing that flexes as demand changes. My mnemonic for the three pillars is IPA: Independence of nodes, Protection through availability, and Adaptive load balancing. Burn that in and you will never confuse the definition of a cluster with a description of a plain old distributed system.
Mei-Ling H.Feb 6, 2026Almost chose D, then A said single system, not multiple.
Brenda K.Feb 25, 2026I went back and forth on D because "single system" and "multiple servers" feel like opposites, and my brain kept second-guessing whether an app-facing illusion of multiple servers counted as a cluster trait, but D is exactly wrong on that point, since a cluster is supposed to look like ONE system to an application, not many. Once I locked that down, A, B, and C fell right into place as the three core pillars you need to have memorized cold before you sit down.
Lena V.Jan 26, 2026D trips people up but clusters present as ONE system, not multiple. A, B, C.
Imani T.Feb 21, 2026Okay so I went back and forth on this one but I keep landing on A, B, and D as my three. Here is my reasoning on D specifically. The whole point of a cluster from an application perspective is transparency, and transparency cuts both ways. The app needs to know there are multiple nodes available so it can reconnect or reroute when one goes down, which is literally the availability story Oracle sells with RAC. If the cluster looked like one server to the app, you lose that awareness and your failover logic has nothing to work with. C talks about dynamic workload balancing which is a feature you configure on top of a cluster, not something that defines what a cluster fundamentally is, so I dropped C. A, B, and D define the structure and purpose, C describes an optional operational mode you layer on afterward. Curious if anyone else read it that way or if I am overthinking the scope of the word "define" in the question stem.
Prof. SaraFeb 23, 2026Imani, you actually flipped the logic on D: cluster transparency means the application sees one logical system and does not need to track individual nodes, so failover awareness lives in the cluster layer, not the app. C belongs because dynamic workload balancing across nodes is a defining architectural characteristic of a cluster, not an optional add-on, which is exactly why A, B, and C is the credited answer.