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Introducing Workers Unbound


6 min read

We launched Cloudflare Workers® in 2017 with the goal of building the development platform that we wished we had. We want to enable developers to build great software while Cloudflare manages the overhead of configuring and maintaining the infrastructure. Workers is with you from the first line of code, to the first application, all the way to a globally scaled product. By making our Edge network programmable and providing servers in 200+ locations around the world, we offer you the power to execute on even the biggest ideas.

Behind the scenes at Cloudflare, we’ve been steadily working towards making development on the Edge even more powerful and flexible. Today, we are excited to announce the next phase of this with the launch of our new platform, Workers Unbound, without restrictive CPU limits in a private beta (sign up for details here).

What is Workers Unbound? How is it different from Cloudflare Workers?

Workers Unbound is like our classic Cloudflare Workers (now referred to as Workers Bundled), but for applications that need longer execution times. We are extending our CPU limits to allow customers to bring all of their workloads onto Workers, no matter how intensive. It eliminates the choice that developers often have to make, between running fast, simple work on the Edge or running heavy computation in a centralized cloud with unlimited resources.

This platform will unlock a new class of intensive applications with heavy computation burdens like image processing or complex algorithms. In fact, this is a highly requested feature that we’ve previously unlocked for a number of our enterprise customers, and are now in the process of making it widely available to the public.

Workers Unbound is built to be a general purpose computing platform, not just as an alternative to niche edge computing offerings. We want to be more compelling for any workload you'd previously think to run on traditional, centralized serverless platforms — faster, more affordable, and more flexible.

Neat! How can I try it?

We are excited to offer Workers Unbound to a select group of developers in a private beta. Please reach out via this form with some details about your use case, and we’ll be in touch! We’d love to hear your feedback and can’t wait to see what you build.

What’s going on behind the scenes?

Serverless as it’s known today is constrained by being built on top of old paradigms. Most serverless platforms have inherited containers from their cloud computing origins. Cloudflare has had the opportunity to rethink serverless by building on the Edge and making this technology more performant at scale for complex applications.

We reap performance benefits by running code on V8 Isolates, which are designed to start very quickly with minimal cold start times. Isolates are a technology built by the Google Chrome team to power the JavaScript engine in the browser and they introduce a new model for running multi-tenant code. They provide lightweight contexts that group variables with the code allowed to mutate them.

Isolates are far more lightweight than containers, a central tenet of most other serverless providers’ architecture. Containers effectively run a virtual machine, and there’s a lot of overhead associated with them. That, in turn, makes it very hard to run the workload outside of a centralized environment.

Moreover, a single process on Workers can run hundreds or thousands of isolates, making switching between them seamless. That means it is possible to run code from many different customers within a single operating system process. This low runtime overhead is part of the story of how Workers scales to support many tenants.

The other part of the story is code distribution. The ability to serve customers from anywhere in the world is a key difference between an edge-based and a region-based serverless paradigm, but it requires us to ship customer code to every server at once. Isolates come to the rescue again: we embed V8 with the same standard JavaScript APIs you can find in browsers, meaning a serverless edge application is both lightweight and performant. This means we can distribute Worker scripts to every server in every datacenter around the world, so that any server, anywhere, can serve requests bound for any customer.

How does this affect my bill?

Performance at scale is top of mind for us because improving performance on our Edge means we can pass those cost savings down to you. We pay the overhead of a JavaScript runtime once, and then are able to run essentially limitless scripts with almost no individual overhead.

Workers Unbound is a truly cost effective platform when compared to AWS Lambda. With serverless, you should only pay for what you use with no hidden fees. Workers will not charge you for hidden extras like API gateway or DNS request fees.

Serverless Pricing Comparison*

Workers Unbound AWS Lambda AWS Lambda @ Edge
Requests (per MM requests) \$0.15 \$0.20 - \$0.28 $0.60
Duration (per MM GB-sec) \$12.50 \$16.67 - \$22.92 $50.01
Data Transfer (per egress GB) \$0.045 \$0.09 - \$0.16 \$0.09 - \$0.16
API Gateway (per MM requests) \$0 \$3.50 - \$4.68 CloudFront pricing
DNS Queries (per MM requests) \$0 \$0.40 \$0.40

* Based on pricing disclosed on as of July 24, 2020. AWS’ published duration pricing is based on 1 GB-sec, which has been multiplied by one million on this table for readability. AWS price ranges reflect different regional pricing. All prices rounded to the nearest two decimal places. Data Transfer for AWS is based on Data Transfer OUT From Amazon EC2 to Internet above 1 GB / month, for up to 9.999 TB / month. API Gateway for AWS is based on Rest APIs above 1MM/month, for up to 333MM/month. Both the Workers Unbound and AWS Lambda services provide 1MM free requests per month and 400,000 GB-seconds of compute time per month. DNS Queries rate for AWS is based on the listed price for up to 1 Billion queries / month.

How much can I save?

To put our numbers to the test, we deployed a hello world GraphQL server to both Workers and Lambda. The median execution time on Lambda was 1.54ms, whereas the same workload took 0.90ms on Workers. After crunching the numbers and factoring in all the opaque fees that AWS charges (including API Gateway to allow for requests from the Internet), we found that using Workers Unbound can save you up to 75% -- and that’s just for a hello world! Imagine the cost savings when you’re running complex workloads for millions of users.

You might be wondering how we’re able to be so competitive. It all comes down to efficiency. The lightweight nature of Workers allows us to do the same work, but with less platform overhead and resource consumption. The execution times from this GraphQL hello world test are shown below and put platform providers’ overhead on display. Since the test is truly a hello world, the variation is explained by architectural differences between providers (e.g. isolates v. containers).

GraphQL hello world Execution Time (ms) across Serverless Platforms*

Cloudflare Workers AWS Lambda Google Cloud Functions Azure Functions
Min 0.58 1.22 6.16 5.00
p50 0.90 1.54 10.41 21.00
p90 1.24 7.45 15.93 110.00
p99 3.32 57.51 20.25 207.96
Max 16.39 398.54 31933.18 2768.00

* The 128MB memory tier was used for each platform. This testing was run in us-east for AWS, us-central for Google, and us-west for Azure. Each platform test was run at a throughput of 1 request per second over the course of an hour. The execution times were taken from each provider's logging system.

These numbers speak for themself and highlight the efficiency of the Worker’s architecture. On Workers, you don’t just get faster results, you also benefit from the cost savings we pass onto you.

When can I use it?

Workers Unbound is a major change to our platform, so we’ll be rolling it out slowly and tweaking it over time. If you’d like to get early access or want to be notified when it’s ready, sign up for details here!

We’ve got some exciting announcements to share this week. Stay tuned for the rest of Serverless Week!

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