Replication, sharding and consistency
Comes up in: Backend design
This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.
What it covers
- leader-follower replication
- read replicas and lag
- sharding keys and hot spots
- CAP and PACELC in plain words
- eventual vs strong consistency
- consistent hashing
Words you will know
What you will practise
- pick a shard key for 3 apps
Interview questions this answers
- Explain the CAP theorem in simple terms.
- What is sharding and what problems does it create?