Netflix’s Distributed Counter: Scalable, Accurate, and Real-Time Counting at Global Scale

If you’ve ever wondered how Netflix keeps track of all those views and clicks in real-time, look no further. The streaming giant has a distributed counter system that’s not only scalable and accurate but also gives up-to-the-minute data on what’s popular.

Netflix’s system relies on Redis, an open-source, in-memory data structure store, to keep track of counts across various categories like popular movies, trending TV shows, and user interactions. The distributed counter system ensures that counts are accurate by using a technique known as “hyperloglog,” which provides an estimate of unique items in a set. This method allows Netflix to handle high volumes of data without sacrificing accuracy.

Netflix engineers have fine-tuned this distributed counter system to ensure that it can handle the massive scale of data generated by millions of users streaming content simultaneously. By using Redis and hyperloglog, they can provide real-time counts that help inform decisions about content recommendations and trending shows.

So next time you see those trending lists on Netflix, know that there’s a sophisticated distributed counter system working behind the scenes to keep you up to date on the latest and greatest in streaming entertainment.