Building a reliable backend is a necessity when it comes to creating a video streaming application. A dependable architecture will ensure minimal latency, scale in accordance with needs, and offer continuity of service at all times. How to achieve this? You must equip it with tools that will prevent technical faults, system faults or running out of storage. There are several strategies you should implement to build a modern and reliable backend. Here are the 10 principles we follow for video streaming system design.
Principle 1: Monitor and measure performance
Implementing relevant metrics with regards to user and system behavior is key for understanding how much resources your infrastructure will require. `You need metrics to know how users behave within an app, where they generate the largest traffic, etc. This knowledge will be crucial for making other decisions as you build and optimize your system.
When building a new application, you can’t know how your customers will behave when using it. You need to know where your users go, where they come from and how they click through your app. You can implement ready-to-use services such as HotJar to help you understand what’s your user’s path in the app. Then, you need to look at how these translate to system usage: understand how many requests you receive in a given instant, which were resolved successfully and which failed. Looking for correlations between those numbers will help you determine the number of required resources.
AWS CloudWatch can be particularly useful in designing a reliable video streaming system, as it can not only monitor your events, but also trigger specific actions once certain events are discovered.
Principle 2: Ensure scalability
Your application must be prepared for sudden spikes in traffic. If your servers or other resources are incapable of handling the number of requests your streaming application receives, it will go down. The same applies to the number of hosts, storage space, etc. Consequently, you will be losing viewers. According to TechRadar, viewers will tolerate a maximum of 90 seconds of a poor-quality stream before they abandon your service.
How to ensure scalability? One of the best options is to benefit from resource auto scaling offered by the cloud. This will require you to set relevant parameters to trigger the autoscaling, however. Do you want additional resources to be added when CPU usage bypasses a specific percentage? Or when memory usage comes close to what threshold? You will have to set such parameters that won’t unnecessarily incur extra costs while ensuring a frictionless experience for your viewers.
Principle 3: Implement redundancy
To avoid application failure, you have to be prepared for potential system faults. In case of a video streaming application architecture, having only a single point of failure is highly risky and may lead to customer loss if your system is down for too long.
The redundancy principle works to ensure that when one system component fails, others are available to take over its function. In case of a video streaming application, a redundant system will provide failover or load balancing support to ensure continuity of the stream. As a rule, a fault-tolerant system must have another platform or duplicate component as a failover mechanism.
Principle 4: Embrace on-demand options where possible
One of the biggest advantages of working with the cloud is that it offers services that allow you to pay only for what you use and not worry about scaling. Many resources are provided through a pay-as-you-go scheme.
Amazon Aurora Serverless or Amazon DynamoDB are good examples of databases with on-demand capacity mode. With these databases, you can keep on adding data as required and whenever required, without having to specify how much read and write throughput you expect.
Principle 5: Implement self-healing mechanisms
While self-healing may sound like a complex principle to implement, it’s not that complicated in practice. Contrary to popular belief, it doesn’t require AI or machine learning mechanisms. Instead, it’s about observing your system to understand common errors and implementing automated recovery steps.
To ensure self healing, consider the following:
- Look at how your system responds to common errors. For instance, if your payment component fails, you could write additional code that redirects users to a third-party provider.
- Increase the efficiency of your information flow. You could, for instance, build a dedicated dashboard that flags missing data in your records and fills these out automatically when it encounters them.
- Make adjustments to problematic data. For instance, if you are missing an email address from your database, you could program it to use an alternate email address instead.
- Implement rules that will prompt your users to perform specific actions that your system is missing.
Principle 6: Implement a Content Delivery Network
A reliable video streaming app architecture must be designed in a way that supports minimal latency and ensures the best possible experience for the viewer. This can be ensured by storing the video content as close to your viewers as possible.
One way to achieve this is by implementing a Content Delivery Network, a network of servers distributed across multiple geographic locations. CDNs work by caching and delivering content from a server that is closest to the viewer. Using a CDN will allow you to store copies of your video content across different locations, which will shorten the transmission path for the viewer. It helps to reduce the time required to fetch the content and thus reduce latency.
With AWS, the CDN service is provided through Amazon CloudFront.
Principle 7: Benefit from serverless
Serverless services allow developers to place the code directly on the infrastructure, meaning that they don’t need to worry about servers at all (these are managed by the vendor directly). Serverless computing can be leveraged in video streaming app development to offload compute-intensive tasks, streamline content delivery, and enable real-time video processing, greatly boosting the efficiency and reliability of your app’s backend. A serverless compute engine you can use for this purpose is AWS Fargate.
One of the key functions that enable serverless is AWS Lambda, which allows developers to run code in response to events without having to manage the underlying infrastructure. It is very effective at running smaller functions and those actions that must be run quickly, which is highly important for video streaming apps. It can be applied for video transcoding, media processing tasks (such as extracting metadata, adding thumbnails, processing the number of likes, etc.).
Principle 8: Embrace loosely-coupled services
Loosely-coupled services are particularly useful in video streaming system design as they enable building a flexible architecture where different components of an app can be scaled independently.
To implement loosely-coupled services into your design, you will need to determine which services are critical for meeting your business goals. Then, define clear service boundaries using lightweight communication protocols, implement asynchronous communication, using APIs for loose coupling, utilize containerization and orchestration, implement fault tolerance and resilience, automate testing and deployment. By following these practices, you can achieve a more scalable, maintainable, and reliable architecture for your video streaming application.
Principle 9: Adjust the stream to user capacity
This strategy is well implemented by Netflix. Adjusting the stream to the capacity of the user’s device and connection capacities. If a user is streaming content via their phone, delivering 4K quality video simply doesn’t make any sense, but it may slow down the experience for the user.
To eliminate this risk, you will have to prepare your content for relevant streaming options. Adjusting it will require prior preparation of different formats, sizes and compressions versions. If live streaming is involved, this task will be somewhat more difficult and will increase latency, as you will have to incorporate a video transcoding mechanism that will convert your stream to a different format on the fly.
Principle 10: Follow AWS Well Architected Framework practices
Amazon’s Well Architected Framework is a set of 6 pillars that help developers build solid application architectures. One of these pillars is fully devoted to ensuring reliability of digital tools and apps.
By working in accordance with the framework, developers can ensure that the backend infrastructure is reliable and resilient, and meets the demands of modern video applications. Following the framework helps to build tools that smooth user experience and minimum downtime. This includes implementing redundancy and failover mechanisms to ensure continuity of service, implementing disaster recovery plans, and using monitoring and alerting tools to quickly detect and remediate issues (which we have already touched upon earlier in this article).
Building a reliable video streaming app architecture with RST Software
We’re hoping that this article shed light on the challenges of building reliable video streaming app architecture. We have a dedicated team that specializes in creating video streaming applications for different purposes and scale, so if you have any questions about your new digital tool, feel free to contact us directly. Send your queries to magda@rst.software and I will make sure you get answers from the person that’s best qualified to provide them. We are also an AWS certified partner, so if you’re planning to build your app in the cloud, we’ll be happy to contribute our AWS expertise to live video streaming system design as well.
