We designed a Superfast KV Store, but can we go faster than this? Let's try to model something that is faster than this superfast DB.
Design a single-node persistent KV Store that supports GET, PUT and DEL operations and it utilizes hardware (disk, RAM) optimally. The response time for all the 3 operations should be as low as possible and complexity of operations should be O(1). It is okay for this KV store to not support infinite number of keys given it is bound to a single node, but make sure you maximize the number of keys a single node can hold.
Note: It is okay if your storage engine cannot support very large number of keys.
The problem statement is something to start with, be creative and dive into the product details and add constraints and features you think would be important.
- should be able to
GET,PUT,DELon a key - all operations should happen as fast as possible with complexity of
O(1) - this KV store is not distributed and will run on just a single node
- make your high-level components operate with high availability
- ensure that the data in your system is durable, not matter what happens
- define how your system would behave while scaling-up and scaling-down
- make your system cost-effective and provide a justification for the same
- describe how capacity planning helped you made a good design decision
- think about how other services will interact with your service
- ensure the data in your system is never going in an inconsistent state
- ensure your system is free of deadlocks (if applicable)
- ensure that the throughput of your system is not affected by locking, if it does, state how it would affect
Create a design document of this system/feature stating all critical design decisions, tradeoffs, components, services, and communications. Also specify how your system handles at scale, and what will eventually become a chokepoint.
Do not create unnecessary components, just to make design look complicated. A good design is always simple and elegant. A good way to think about it is if you were to create a spearate process/machine/infra for each component and you will have to code it yourself, would you still do it?
To understand the nuances and internals of this system, build a prototype that
- implement your design and measure the
GET,PUT,DELperformance
This is a recommended tech-stack for building this prototype
| Which | Options |
|---|---|
| Language | Golang, Java, C++, Python |
These are the common pitfalls that you should keep in mind while you are building this prototype
- your storage engine will always be bound to single node
- it is okay for your engine to not support very large number of keys
- designing storage engine
- utilizing every ounce of your hardware
If you find this assignment helpful, please
- share this assignment with your friends and peers
- star this repository and help it reach a wider audience
- give me a shoutout on Twitter @arpit_bhayani, or on LinkedIn at @arpitbhayani.
This assignment is part of Arpit's System Design Masterclass - A masterclass that helps you become great at designing scalable, fault-tolerant, and highly available systems.