Amazon Web Services tops list of most reliable public clouds

Google and Microsoft now host public clouds meant to give Amazon Web Services a run for its money, but they still have a way to go to rival good ol’ AWS in terms of uptime, according to cloud reliability ratings by CloudHarmony.

The Laguna Beach, California company tracks status of more than 30 clouds from AWS to Zettagrid, including a couple I’ve never heard of, so take a look.

Filtering worldwide downtime over the past year, the [company]Amazon[/company] S3 storage service, for example, registered 23 outages for a total of 2.69 hours of downtime, while EC2 compute logged 20 outages accounting for 2.41 hours out, according to CloudHarmony’s CloudSquare status metrics.

By contrast, the [company]Google[/company] Compute Engine component of Google Cloud Platform showed 72 outages for 4.42 hours downtime and Google Cloud Storage reported 8 outages adding up to 14.23 minutes down.

And [company]Microsoft[/company] Azure Virtual machines fell more than 92 times for nearly 40 hours of downtime over 12 months — including a significant outage in November; Azure Object Storage was off 141 times for 10.97 hours.

Some caveats

Jason Read, co-founder of CloudHarmony, acknowledged that the service can’t and won’t record every glitch. For example, it monitors only relatively recent M3 large EC2 instances running in one Availability Zone per AWS Region. So if there were glitches in older AWS instances during the great Xen reboot of 2014, they wouldn’t show up. And CloudHarmony only “watches” Linux instances running in Microsoft Azure.

So take a look at the numbers, but remember they represent a subset of total cloud resources from each provider.

cloudharmony AWS

CloudHarmony Google

Microsoft Cloud Harmony