Why caching reduces latency in HLD - Quick Recap

Recall & Review

beginner

What is caching in system design?

Caching is storing copies of data in a faster storage location to quickly serve future requests without fetching from the original slower source.

beginner

How does caching reduce latency?

Caching reduces latency by serving data from a nearby, faster storage instead of waiting for slower backend or database responses.

beginner

What is latency in the context of system design?

Latency is the delay or time taken for a system to respond to a request.

intermediate

Why is accessing cache faster than accessing a database?

Cache is usually stored in memory or close to the user, making access much faster than querying a database which may be on a remote server or disk.

intermediate

What happens if cached data is outdated?

If cached data is outdated, the system may serve stale information unless cache invalidation or refresh strategies are used.

What is the main benefit of caching in reducing latency?

A Serving data from faster storage close to the user

B Increasing the size of the database

C Adding more servers to the backend

D Compressing data before sending

Caching stores data in faster storage like memory, reducing the time to access data and thus lowering latency.

Which storage is typically faster for caching?

A Hard disk drive

B In-memory storage

C Remote database server

D Cloud storage

In-memory storage is much faster than disk or remote servers, making it ideal for caching.

What does latency measure in a system?

A Amount of data stored

B Number of users connected

C Time delay to respond to a request

D Size of the cache

Latency is the time delay between sending a request and receiving a response.

If cache is not used, what usually happens to latency?

A Latency increases

B Latency stays the same

C Latency decreases

D Latency becomes zero

Without cache, data must be fetched from slower sources, increasing latency.

Which of these is a challenge when using caching?

A More network hops

B Increasing database size

C Slower data access

D Cache invalidation and stale data

Managing cache freshness and invalidation is a key challenge to avoid serving outdated data.

Explain in simple terms why caching helps reduce latency in a system.

Think about how getting something from a nearby shelf is faster than going to a distant store.

Describe the potential downside of caching related to data freshness and how it can be managed.

Consider what happens if you keep using an old map instead of updating it.