Serverless Performance: Cloudflare Workers, Lambda and Lambda@Edge

A few months ago we released a new way for people to run serverless Javascript called Cloudflare Workers. We believe Workers is the fastest way to execute serverless functions, but lets prove it. At the 95th percentile, Workers is 441% faster than a Lambda function, and 192% faster than Lambda@Edge.

The functions being tested simply return the current time. All three scripts are available on Github. The testing is being done by a service called Catchpoint which has hundreds of testing locations around the world.

To be fair, comparing my Lambda, which only runs in us-east-1 (Northern Virginia, USA), to a global service like Workers is a a little unfair. This effect becomes even more clear if I only show tests ran in Australia. Sydney is 9,735 miles (53 light-ms) from our instance in us-east-1.

It becomes pretty clear how miserable the experience would be for visitors down south: As we only run one instance of each test from Australia every five minutes that’s not a conclusive amount of data though, so let’s look at the percentile distribution for the past 24 hours: The 50th percentile speed for Workers is 13ms, well faster than a packet could even get half way to Virginia. At the 95th percentile you’re looking at 882ms for Lambda, 216ms for Lambda@Edge, and 40ms for Workers.

A full 5% of your users will be waiting almost a second for the simplest possible Lambda response, making it impossible to build a responsive application. As we said, Workers has quite the advantage being deployed everywhere, as compared to Lambda which lives in a single region. (Lambda@Edge has less of an excuse).

We believe Worker performance should be great everywhere though, so lets look a little closer to our Lambda instance. First all the tests in North America:

Source: cloudflare.com