Amazon EC2 outage affects Reddit, Foursquare, Quora

22 Apr 2011

Amazon’s Elastic Cloud Compute (EC2) servers failed yesterday, bringing down numerous sites, such as Reddit, Foursquare and Quora.

The outage affected the EC2 service at Amazon’s Northern Virginia site, which handles AWS operations on the east coast of the US.

According to Amazon, a “networking event” triggered a large amount of re-mirroring of elastic block storage (EBS) volumes in availability zones in US East.

The re-mirroring created a shortage of capacity in one of these zones, impacting EBS volume creation.

Along with this, one of Amazon’s internal control planers for EBS became inundated, also making it difficult to make new EBS volumes and backed instances.

Along with bringing down major sites such as Reddit, Foursquare and Quora, Amazon’s relational database service and its Elastic Beanstalk for deploying, managing and monitoring services were also affected.

Amazon EC2 is a web service providing resizable compute capacity in the cloud, designed to make web-scale computing easier for developers. Customers can avail of a pay-as-you-go basis to increase or decrease servers as and when they need to.

One concern raised in this outage was how it affected numerous “availability zones” which Amazon said were “distinct locations engineered to be insulated from failures in other availability zones.”