Global Accelerator is not decreasing file download times



I have been benchmarking CloudFront (without cache) and Global Accelerator and I don't really understand results of the latter one.


Web application in Ireland, delivering static content for testing (jpeg, js, html...) on EC2.

Application Load Balancer in front.

CloudFront test
I created a global CloudFront distribution without any caching in order to utilize private AWS backbone network. The goal was to decrease network latency between Ireland (server) and Japan/US (client). I compared file download times with and without CloudFront. I.e., direct connection from Japan/US to Ireland via public Internet vs. via CloudFront. Results were good, on average file (js, jpeg, html...) download duration was ~50 % via CloudFront vs. direct connection to ALB in Ireland.

Global Accelerator test
I performed equal test to CloudFront test but by using Global Accelerator and two static IP addresses. I expected to see similar improvements in download speeds but I was wrong. Duration of file download was just slightly decreased when downloading via either GA IP. In contrast, in Europe area it was slower to download files via GA than it was via direct connection to ALB.

I checked traceroute resulsts from Japan and US to web app (Ireland/ALB) with and without GA. I did verify that with GA there are much less hops as it is jumping into AWS network via edge node.

Do I have understood something wrong in GA, or why it is not improving download performance in way CloudFront does? Is it related to the implementation of CloudFront where it keeps TCP connections warm/open from edge to backend and GA is not doing that?

asked 3 years ago71 views
1 Answer

Global Accelerator’s performance depends on many factors, such as the performance measurement tools used, proximity of test region to AWS Regions, Global Accelerator’s high availability/fault isolating design, and proximity of test region to Global Accelerator deployments. In general, the farther your users are from the AWS Region, the better will be the performance via Global Accelerator. We shall contact you to understand more about your test set-up and recommend optimizations if any.

answered 3 years ago

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions