Incident review: API and Dashboard outage on 10 October 2017
This post represents the collective work of our Core Infrastructure team's investigation into our API and Dashboard outage on 10 October 2017.
As a payments company, we take reliability very seriously. We hope that the transparency in technical write-ups like this reflects that.
We have included a high-level summary of the incident, and a more detailed technical breakdown of what happened, our investigation, and changes we've made since.
On the afternoon of 10 October 2017, we experienced an outage of our API and Dashboard, lasting 1 hour and 50 minutes. Any requests made during that time failed, and returned an error.
The cause of the incident was a hardware failure on our primary database node, combined with unusual circumstances that prevented our database cluster automation from promoting one of the replica database nodes to act as the new primary.
This failure to promote a new primary database node extended an outage that would normally last 1 or 2 minutes to one that lasted almost 2 hours.