The recent spurt seen in streaming activity will be one of the many things that COVID-19 will leave behind as a legacy. However, this super fest of content consumption across dozens of streaming apps was in play last year itself as if all of this were prescience.
From March 9 to March 16, the total streaming time grew to 156.1 billion minutes per day in the United States, compared to 127.6 billion minutes during the last week of February, as per Nielsen. In March, streaming accounted for 23% of consumer TV viewing time, up from 21% in February and 14% a year ago.
All the major platforms have shown adaptability and scalability in handling the increased workload. It is a testament to the idea of cloud engineering and modern application concepts such as microservices. The core architecture of the streaming applications has evolved a long way over the last decade to be able to be so flawless now. This blog post tries to explore the concepts that are fundamental to building steady data streaming applications.
There are many functional and performance requirements for which an OTT service must be ready:
- Sensitivity to the bandwidth disparities in different networks and the fluctuations in network bandwidth
- Performance latency and buffering issues
- Ever-increasing catalog of content to be made searchable and accessible
- Access to vast content on a site or app that is lightweight
- Prevent latency issue es for popular and most liked content
- Handle high load and ability to deliver to all requests
- Maintain consistency of the content usage across devices and time zones
- Security and data encryption as well as entitlement
- Ability to store and record billions of user actions and then process and use the insight to make the service better
- Intuitive user experience across different screen and device sizes
These are but some of the requirements that a good streaming service would require to fulfill. While there are too many things from an architecture perspective that go into the building of a streaming app, we will try to cover a few foundation elements.
Edge Computing and CDNs: Content is delivered to devices through CDNs, which act as the cache for the content. Edge computing uses the power of the cloud and takes computing power close to the end device. This is the first layer of logic that interacts with devices, and it links the request to the appropriate API within the services architecture. It also provides the abstraction layer to the mid-tier services.
Load Balancing: This helps the streaming service manage peaks in the load by implementing throttling mechanisms that reject the extra incoming requests and diverting them to other servers when the traffic crosses a threshold.
Microservices: The entire backend application is split into hundreds of independent services. These services implement specific business logic, hence encapsulating one service from another. This enables the entire service to function without the risk of one flaw bringing the whole application down to its knees. These services provide functions such as authentication, licensing, playback, artwork, etc.
Encoding and Content Delivery: Every media file is broken into chunks and transcoded into different bit rates. This is done to provide the best possible quality to different devices at varying bandwidths. Every media content demands its quality standards. A fast-moving video will require transcoding at a higher quality than a video, which is relatively slow-moving. Adaptive streaming is used to push the most appropriate bit rate segment of the video. Local caching is used to serve subscribers. Push fill methodology is used to load the content in a regional CDN based on the popularity of the content in that region.
Data pipelines: Data is created at an enormous scale since billions of events take place in a day and millions in a second. A data pipeline must be designed to enable the cloud storage of the video viewings and UI activities. This data is used for big data analytics. This, along with device error logs and diagnostic events, is also used for monitoring and debugging operations.
Final Thoughts
Like Rome was not built in a day, it takes time to build excellent streaming services. Most of these components of a service evolve over time. The three goals of any streaming service to achieve architectural excellence are scalability, availability, and immutability. Scalability enables the streaming service to scale for massive audiences and handle spikes efficiently. Availability allows the service to be available for requests while maintaining the site’s performance. Immutability provides robustness to the architecture so that any change to the infrastructure on the fly does not upset the system and disrupt the service.
Companies can use third party tools or build the components on their own, depending on the scale of the service they are trying to develop. Custom build applications provide more control to the companies, and they can build services based on their requirements. Several open-source components can be used, which can be then built upon to create exciting, viable products that can scale quickly.
