Current status: All our ducks are in a row.

What is this site? We monitor the status of coursera.org and our class sites, and we update here whenever there are interruptions in service.

Friday, September 28, 2012

9-28-2012

We experienced downtime on class.coursera.org and www.coursera.org from approximately 4:25 to 4:45 PST.

We traced the outage to an issue with our MongoDB database and are taking steps to prevent it from happening in the future, and to recover faster.

We apologize for the outage and have emailed affected students to let them know.

Sunday, September 23, 2012

9-23-12

We experienced downtime on class.coursera.org and www.coursera.org from approximately 5:00 to 7:00 AM PST.

One of our critical distributed databases went into an inconsistent state. When the database is in an inconsistent state, it brings down all class websites. We were already in the process of transitioning off this database system, and hope to fully decommission this system within 2 weeks. We apologize for the inconvenience this caused.

For students working on assignments that were due, we moved the deadline forward.

Monday, September 10, 2012

9-10-12


Summary:
Today, GoDaddy, our DNS provider went down in an attack, bringing coursera.org and others with it. (BBC, ZDNet)  We worked quickly to transfer all our DNS off of GoDaddy. We have now restored service using Amazon's Route 53 service, and are back online.

4:30pm PST: All services operational. Our TTL should have expired globally, and service should be back to normal.

2:15pm PST: We were able to reach GoDaddy's web interfaces, and have transferred our DNS name servers to Route53. Services should be returning as the TTL on GoDaddy's name servers expires.

11:45am PST: We are unable to reach GoDaddy's servers ourselves, and are locked out of our DNS settings.

11:30am PST: We are getting reports of DNS not resolving. Investigating...