Hard Design: Distributed Key-Value Store (Redis/DynamoDB)
What is the purpose of a Write-Ahead Log (WAL) in a KV store?
— Tests your understanding of this concept.
Answer Options
A To log read operations
B To ensure durability: if node crashes, WAL allows recovery of in-memory data that wasn't yet flushed to disk
C To distribute writes across nodes
D To improve write performance
Want to see the correct answer?
Get the answer with a detailed explanation, plus practice 22+ more Design: Distributed Key-Value Store (Redis/DynamoDB) questions with adaptive quizzes and timed interviews.
See the Answer on Guru Sishya →This question is from the Design: Distributed Key-Value Store (Redis/DynamoDB) topic (System Design Cases).
More Design: Distributed Key-Value Store (Redis/DynamoDB) Questions
What does the CAP theorem state?
HardWhat is the advantage of consistent hashing over modulo hashing for data distribution?
HardFor N=3 replicas, W=2 writes, R=2 reads: is strong consistency achieved?
HardTwo clients simultaneously write different values to the same key on two different nodes (network partition). How do you resolve this conflict?
HardWhat is the purpose of virtual nodes (vnodes) in consistent hashing?
Hard