Explore essential CAP theorem concepts as they apply to practical scenarios in distributed databases and systems. This engaging quiz helps users understand how Consistency, Availability, and Partition Tolerance influence real-world architectural decisions and trade-offs.
According to the CAP theorem, what three properties must distributed systems balance, especially when facing network failures?
Explanation: Consistency, Availability, and Partition Tolerance are the three properties defined by the CAP theorem for distributed systems. The other options mention unrelated concepts: Confidentiality, Accessibility, and Performance are not central to CAP, nor are Capacity, Adaptability, Portability, or Connectivity, Accuracy, Persistence. Understanding these three key properties is crucial for anyone working with distributed data systems.
If a distributed database experiences a network partition, which two properties can it maintain according to the CAP theorem?
Explanation: During a network partition, a system can only choose to guarantee two out of the three CAP properties, often Partition Tolerance and Availability or Partition Tolerance and Consistency. In this context, Partition Tolerance and Availability is the most correct answer. The options Flexibility and Accuracy are not part of the CAP theorem, and Consistency alone cannot be guaranteed in the presence of both partitions and availability.
Which type of real-world system would prioritize Consistency and Availability but sacrifice Partition Tolerance during network issues?
Explanation: A single reliable server is typically not exposed to network partitions, allowing it to maintain both Consistency and Availability easily. Sensor networks, peer-to-peer apps, and blockchains are distributed and must handle partitions, making them more focused on Partition Tolerance. The correct identification of system type is important in understanding CAP trade-offs.
In a distributed shopping cart system, which CAP property is prioritized if the system always shows the same recent contents to all users, even during network splits?
Explanation: Showing the same recent contents to all users means the system guarantees Consistency. Portability and Efficiency are unrelated to CAP theorem, and Availability would allow users to see divergent cart contents during partitions. Prioritizing consistency may limit availability when partitions happen.
A social media platform allows users to post updates even when some servers cannot communicate. Posts might not be immediately visible to everyone. Which CAP properties does this system prioritize?
Explanation: Allowing posts even during server disconnections shows the system values both Availability and Partition Tolerance, but may relax Consistency. Accuracy and Portability are not CAP properties, and Consistency and Availability cannot both be guaranteed during network partitions.
When a distributed system favors Availability over Consistency during a network partition, what user experience issue is most common?
Explanation: Favoring Availability over Consistency means the system continues accepting requests, but users may see old or conflicting data when partitions exist. Servers being unreachable or interfaces inaccessible describes loss of Availability, not Consistency. Not all transactions are rolled back, but rather there may be temporarily inconsistent states.
Why is Partition Tolerance usually considered necessary in globally distributed databases?
Explanation: Partition Tolerance is essential because network failures or partitions are inevitable in large, distributed systems. Needing backups, improving authentication, or completely eliminating consistency issues are not directly linked to Partition Tolerance. Recognizing network unreliability is a core reason for designing Partition Tolerance into distributed architectures.
In a distributed chat application, sacrificing Consistency during a partition allows which outcome?
Explanation: When consistency is sacrificed, users may see messages in varying order or might not see the latest messages simultaneously. Loss of schema or automatic deletion of accounts are not related to CAP trade-offs, and network latency never drops to zero due to architectural decisions about consistency.
For a collaborative document editing tool, what would be a likely CAP trade-off if user edits must always be saved, even during connectivity issues?
Explanation: Guaranteeing that edits are always saved during connectivity problems prioritizes Availability and Partition Tolerance, possibly at the expense of strict Consistency. Portability and Performance are not CAP properties, and relying only on Partition Tolerance without considering others ignores necessary trade-offs.
Which property should a banking system never sacrifice, even during network partitions, to avoid double-spending?
Explanation: A banking system must always prioritize Consistency to prevent problems like double-spending or incorrect balances. Adaptability is not a CAP property. Partition Tolerance and Availability are important, but compromising Consistency can seriously impact reliability and correctness for financial transactions.