Content Comparison

Introduction

URL shortening is used to create shorter aliases for long URLs. We call these shortened aliases “short links.” Users are redirected to the original URL when they hit these short links. Short links save a lot of space when displayed, printed, messaged, or tweeted. Additionally, users are less likely to mistype shorter URLs.

//Shorten long URL through TinyURL
from https://www.educative.io/courses/grokking-the-system-design-interview/m2ygV4E81AR
to https://tinyurl.com/rxcsyr3r

Step 1 - Understand the problem and establish design scope

Back-of-the-envelope calculation

For Traffic

• Write operations: 100 million URLs are generated per day

• Write operation per second: 100 million / 24 / 3600 sec = 1160 operation per sec.

• Read operation: Assuming 1160 * 10 = 11600 read per sec.

• Assuming the URL shortener service runs for 10 years, this means we must support 100 Million * 365 * 10 = 365 billion records.

• Assuming average length is 100

For Storage

• Storage requirement over 10 years : 365 billion * 100 bytes = 36.5 TB.

Step 2 - High-level design

API endpoints

A URL shortener primary needs 2 API endpoints :

• URL Shortening : to create a new short url, a client sends a POST request which contains one parameter: the original long URL.

  • POST api/v1/data/shorten : return short url.

• URL redirecting : to redirect a short URL to the corresponding long URL, a client sends a GET request.

  • GET api/v1/shortUrl : return long url for http redirection.

URL redirecting

301 redirect Shows that the request URL is permanently moved to the log URL. So, the browser caches the response, and subsequent requests for the same URL will not be sent to the URL shortening service. Instead, requests are redirected to the long URL server directly.

URL shortening

How do we encode the actual URL ? www.tinyurl.com/{hashValue}.

Image Added

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Step 3 - Design deep dive

Step 4 - Pros & Cons