Database

Let us explore some of the choices for System Design of Databases of URL Shortner:

• We can use RDBMS which uses ACID properties but you will be facing the scalability issue with relational databases.
• Now if you think you can use sharding and resolve the scalability issue in RDBMS then that will increase the complexity of the system.
• There are 30M active users so there will be conversions and a lot of Short URL resolution and redirections.
• Read and write will be heavy for these 30M users so scaling the RDBMS using shard will increase the complexity of the design.

You may have to use consistent hashing to balance the traffics and DB queries in the case of RDBMS and which is a complicated process. So to handle this amount of huge traffic on our system relational databases are not fit and also it won’t be a good decision to scale the RDBMS. 

So let’s take a look at NoSQL Database:

• The only problem with using the NoSQL database is its eventual consistency.
• We write something and it takes some time to replicate to a different node but our system needs high availability and NoSQL fits this requirement.
• NoSQL can easily handle the 30M of active users and it is easy to scale. We just need to keep adding the nodes when we want to expand the storage. 

The need for efficient and concise URL management has become a big matter in this technical age. URL shortening services, such as bit.ly, and TinyURL, play a massive role in transforming lengthy web addresses into shorter, shareable links. As the demand for such services grows, it has become vital to undertand the System Design of URL Shortner and mastering the art of designing a scalable and reliable URL-shortening system, to gain a crucial skill for software engineers.

This article gets into the System Design of URL Shortner (URL Shortening Service), which will help in architecting a robust system that can seamlessly generate and redirect short URLs while ensuring scalability, durability, and high availability.