Redis easy
In the context of Redis messaging, what is the functional definition of the 'Pub/Sub' feature?
- A A mechanism for publishing internal database health logs to a remote monitoring dashboard.
- B A real-time broadcast system where publishers send data to active subscribers on channels.
- C A specialized engine for publishing static web pages directly from the internal string cache.
- D A client-side library for subscribing to third-party social media feeds via the Redis API.
Answer: B. A real-time broadcast system where publishers send data to active subscribers on channels.
Pub/Sub allows for decoupling. A publisher sends a message (like a chat update) to a channel, and Redis instantly pushes it to everyone currently 'listening' (subscribed) to that specific name.
One system design question a day, with spaced repetition so the ones you miss come back.
Get the appRelated questions
- If the Redis memory limit is reached, what specific behavior is exhibited by the `allkeys-lru` eviction policy?
- What is the defining characteristic of a Redis 'Set' data type compared to a standard Redis 'List'?
- How does the Redis background snapshotting process (`BGSAVE`) leverage the operating system's `fork()` mechanism to minimize memory overhead?
- Why does Redis proactively disconnect a Pub/Sub client that exhibits high 'output buffer' usage relative to its ingestion rate?
- How does a 'Sorted Set' (ZSET) manage its internal membership and ordering differently from a plain Set?
- Which basic Redis command is used to store or update a simple String value associated with a specific key?