Return of the Monolith: Amazon Dumps Microservices for Video Monitoring

A blog post from the engineering team at Amazon Prime Video has been roiling the cloud native computing community with its explanation that, at least in the case of video monitoring, a monolithic architecture has produced superior performance than a microservices and serverless-led approach.

For a generation of engineers and architects raised on the superiority of microservices, the assertion is shocking indeed. In a microservices architecture, an application is broken into individual components, which then can be worked on and scaled independently.

“This post is an absolute embarrassment for Amazon as a company. Complete inability to build internal alignment or coordinated communications,” wrote analyst Donnie Berkholz, who recently started his own industry-analyst firm Platify.

“What makes this story unique is that Amazon was the original poster child for service-oriented architectures,” weighed in Ruby-on-Rails creator and Basecamp co-founder David Heinemeier Hansson, in a blog item post Thursday. “Now the real-world results of all this theory are finally in, and it’s clear that in practice, microservices pose perhaps the biggest siren song for needlessly complicating your system. And serverless only makes it worse.”

In the original post, dated March 22, Amazon Prime Senior Software Development Engineer Marcin Kolny explained how moving the video streaming to a monolithic architecture reduced costs by 90%. It turns out that components from Amazon Web Services hampered scalability and skyrocketed costs.

The Video Quality Analysis (VQA) team at Prime Video initiated the work.

The task as to monitor the thousands of video streams that the Prime delivered to customers. Originally this work was done by a set of  distributed components orchestrated by AWS Step Functions, a serverless orchestration service, AWS Lambda serverless service.

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In theory, the use of serverless would allow the team to scale each service independently. It turned out, however, that at least for how the team implemented the components, they hit a hard scaling limit at only 5% of the expected load. The costs of scaling up to monitor thousands of video streams would also be unduly expensive, due to the need to send data across multiple components.

Initially, the team tried to optimize individual components, but this did not bring about significant improvements. So, the team moved all the components into a single process, hosting them on Amazon Elastic Compute Cloud (Amazon EC2) and Amazon Elastic Container Service (Amazon ECS).

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Takeaway

Kolny was careful to mention that the architectural decisions made by the video quality team may not work in all instances.

“Microservices and serverless components are tools that do work at high scale, but whether to use them over monolith has to be made on a case-by-case basis,” he wrote.

To be fair, the industry has been looking to temper the enthusiasm of microservices over the past decade, stressing it is only good in some cases.

“As with many good ideas, this pattern turned toxic as soon as it was adopted outside its original context, and wreaked havoc once it got pushed into the internals of single-application architectures,” Hansson wrote. “In many ways, microservices is a zombie architecture. Another strain of an intellectual contagion that just refuses to die.”

The IT world is nothing but cyclical, where an architectural trend is derided as hopelessly archaic one year can be the new hot thing the following year. Certainly, over the past decade when microservices ruled (and the decade before when web services did), we’ve heard more than one joke in the newsroom about “monoliths being the next big thing.” Now it may actually come to pass.