Hotstar is a popular Indian 🇮🇳 digital and mobile entertainment platform 📺. It offers a wide range of digital media content, including TV shows, movies 🎬, and sports events (such as cricket matches 🏏 from the Indian Premier League and other sports tournaments).
Have you ever checked in live cricket 🏏 matches 📺, there is a count on top, like 67L Viewers 📈.
Have you ever wondered how Hotstar handles this huge traffic? 📈
In 2019, During the ICC World Cup Semi-Final between India and New Zealand 🏏, Hotstar set a new record of 25.3 million viewers. Similarly, Hotstar set a new record of 35M concurrent users during the recent IND vs PAK World Cup 2023. That was a huge count.
Challenges faced by Hotstar
In 2019 when Dhoni came for batting 🏏 sudden spike 📈 was noticed in traffic, taking it to 25.3M concurrent users. But then Dhoni got out, and there was a drastic drop 📉 from 25.3M to less than 1M.
There is first challenge is to handle such sudden spikes 📈 and drops 📉 also when users are dropped, some of them exit from the app entirely and others return to the homepage. that leads to an increase in load on homepage services.
-> Challenges with autoscaling.
-> Load testing for millions.
-> Chaos engineering at a high level.
How did Hotstar overcome these challenges?
• Autoscaling: Hotstar does not use traditional autoscaling from AWS because it comes with challenges 🧱, such as insufficient capacity errors ❌, single instance type per auto-scaling group, and step size autoscaling groups. Instead of this Hotstar uses custom scaling policies that are traffic-based 🚦 and ladder based 🪜. It allowed automated pro-active scale-up buffers to handle the sudden spikes 📈.
• Load testing: For load testing, Hotstar has project HULK. Project HULK is an in-house performance 🏋️ testing framework developed by Disney+ Hotstar. It allows Hotstar's engineers ⚙️ to simulate the entire user journey with different inputs and can also simulate entire traffic patterns. This helps them to identify 🔬and fix potential bottlenecks and performance issues before they affect real users.
• Content delivery network 🌐: Hotstar uses a CDN 🌐 to deliver content to users from servers that are located close to them 📡. This helps to reduce latency and improve the streaming experience for users.
• Chaos Engineering 🛠️: Chaos Engineering 🛠️ can be used to identify 🔍 and mitigate single points of failure in Hotstar's system 🖥️. By using Chaos Engineering to test the system's ability to handle these different types of failures.
Panic Mode 🔴:
Hotstar uses panic mode when it experiences a major outage or disruption. It turns off 🚫 non-critical services and graceful degradation, P0 services must be always up.