Use Amazon MemoryDB for Redis in Multi-AZ mode for a real-time game leaderboard

SAP-C02 By islever Editorial Last updated

Design a solution to meet performance objectives. Design a strategy to meet reliability requirements. Determine a strategy to improve performance.

Short answer

B Create an Amazon MemoryDB for Redis cluster in Multi-AZ mode and point the application at the primary node.

Question

A company is migrating infrastructure for its massive multiplayer game to AWS. The game’s application features a leaderboard where players can see rankings in real time. The leaderboard requires microsecond reads and single-digit-millisecond write latencies. The datasets are single-digit terabytes in size and must be available to accept writes in less than a minute if a primary node failure occurs. The company needs a solution in which data can persist for further analytical processing through a data pipeline. Which solution will meet these requirements with the LEAST operational overhead?
  1. Create an Amazon ROS database with a read replica. Configure the application to point writes to the writer endpoint. Configure the application to point reads to the reader endpoint.
  2. Create an Amazon MemoryDB for Redis cluster in Muit-AZ mode Configure the application to interact with the primary node. Correct Answer
  3. Create multiple Redis nodes on Amazon EC2 instances that are spread across multiple Availability Zones. Configure backups to Amazon S3.

Key Takeaways

Amazon MemoryDB for Redis is a fully managed in-memory database that delivers the required latencies, and its Multi-AZ mode replicates to a standby in a second Availability Zone so a failover promotes a new primary in under a minute with no self-managed nodes.

A multiplayer game leaderboard needs microsecond reads, single-digit-millisecond writes, terabyte-scale datasets, and the ability to accept writes within a minute of a primary node failure. The data must also remain available for downstream analytical processing.

Common mistake: Choosing self-managed Redis nodes on EC2. It can meet the latency numbers, but the company would own patching, failover orchestration, monitoring, and backups, which contradicts the least operational overhead requirement, and it is also the wrong answer in the export because option C also adds manual S3 backups.

Expert Analysis

Why the Answer Is Correct

Amazon MemoryDB for Redis delivers microsecond read and single-digit-millisecond write latency on a Redis-compatible in-memory engine, which is exactly what a real-time leaderboard needs. In Multi-AZ mode the data is replicated to a standby node in a second Availability Zone, and MemoryDB promotes that standby automatically when the primary fails, typically in well under a minute, so the write availability requirement is met without any operational intervention. Because it is a managed service, there are no nodes to patch, reconfigure, or back up by hand.

Why the Other Options Are Wrong

A: An Amazon Aurora cluster with a read replica is a relational option with microsecond latency reserved for specific in-memory compute, not general-purpose in-memory reads, and it adds a separate read path that the leaderboard does not need. C: Running Redis on EC2 instances across Availability Zones meets the latency target but requires the company to manage the cluster, and configuring backups to S3 is itself an operational task. Neither the patch cycle nor the failover orchestration is offloaded to AWS.

Community Comment Notes

The community vote was 80 to 20 for C over B, and this split reflects a mis-parse in the dataset rather than a genuine disagreement: several commenters asked where option A had gone, which shows they were reading a reordered option list. The comments that do address the content argue from the MemoryDB product characteristics, and one explicitly notes MemoryDB delivers the ultra-fast Redis performance at issue. On the merits and on the least-operational-overhead wording, MemoryDB for Redis in Multi-AZ mode is the correct answer.

Official Reference

https://docs.aws.amazon.com/memorydb/latest/devguide/what-is-memorydb.html

This link opens the official vendor documentation in a new tab.

Community Votes

C
80%
B
20%

80% of anonymous learners picked answer C. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 6 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 6

  1. zapper1234 👍 7
    memobrydb for ultra-fast Redis performance, so C
  2. vip2 👍 3 Answered C
    MEM DB for gaming leaderboard with related latency requirement
  3. AzureDP900 👍 2
    C is right. Amazon MemoryDB for Redis is a fully managed, Redis-compatible, in-memory database service that delivers ultra-fast performance with microsecond read and single-digit millisecond write latencies. It supports Multi-AZ replication for high availability and durability. If the primary node fails, MemoryDB automatically fails over to a replica node in less than a minute.
  4. TomTom 👍 1 Answered B
    To meet the requirements of low latency and high availability for a gaming leaderboard, Amazon MemoryDB for Redis is the best solution. It provides microsecond read latencies and single-digit millisecond write latencies, ensuring fast data access and updates, which is critical for real-time applications like leaderboards. This setup minimizes operational overhead compared to managing multiple EC2 instances or configuring a traditional RDS database
  5. chris_spencer 👍 5
    where is A?
Show 1 more comment
  1. rohan0411 👍 2
    It is C for sure

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