Capacity shortage hits AWS UK micro instances

Elastic cloud snaps back

Amazon's brand-new UK T2 micro instances reached saturation point on Friday, with users being told the AWS service had run out of local capacity.

Customers were informed that T2 micro instances were running short of rack space in the EU West 2a availability zone in the morning.

The AWS zone is in London and opened in December – AWS operates two more EU zones, in Ireland and Frankfurt.

Amazon is unwilling to detail its UK setup but The Register understands the UK zones have been floated using the data centres of two partner service providers rather than AWS break ground and build its own infrastructure.

AWS tweeted on Friday:

EC2 (London) - t2.micro Instance Capacity - 9:46 AM PDT We are temporarily running low on t2.micro instance capacity in the EU-WEST-2

— AWS SHD (@aws_shd) March 24, 2017

And it posted the following alert on its health dashboard:

Users, however, seem to have only stumbled across the issue. One Reg reader trying to access the local, three-month-old T2 micro instances received the following message:

We currently do not have sufficient t2.micro capacity in the Availability Zone you requested (eu-west-2a).

It is not unusual for AWS to run out of T2 micro instances shortly after their release.

Users attempting to access T2 micro instances in Asia Pacific North East region in August 2014 were told capacity had maxed out, barely after release in July:

でたー！　"We currently do not have sufficient t2.micro capacity in the Availability Zone you requested (ap-northeast-1a)."

— Aya Komuro (@ayakomuro) August 15, 2014

Amazon was, at the time of writing, unable to say why its normally elastic compute cloud was unable to keep the newly launched UK micro instances from running dry.

T2 instances are designed as a low-cost, general-purpose computing unit. Seven classes of T2 instances exist, ranging in capacity from nano to extra large. The idea is users can burst traffic to AWS that might otherwise not take a full CPU or might take more than the standard CPU available on regular instances.

T2 instances target web servers, developer environments and small databases. ®