Current status: All our ducks are in a row.

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

Friday, February 22, 2013

2013-02-22: Site Outage Conclusion

Earlier today, we experienced site-wide intermittent access and high latency issues. We've now resolved these issues, and have determined the underlying causes.

The launch of the new course catalog, with its interactive search features, unfortunately came with a glitch that caused an overload on the database that serves In an attempt to address the performance issues this morning, we transitioned from our primary database to our secondary database on Amazon Web Services. However, the Amazon hardware that the secondary database was located on appears to have been malfunctioning.

After exhausting other options, we moved away from this secondary machine to another one. Immediately after, all our performance metrics recovered. We have been gradually restoring disabled home page features. Throughout most of this, our in-course experience continued to function normally, with only brief minor interruptions.

We sincerely apologize for the inconvenience this has caused. We take reliability very seriously and will be reviewing the timeline and causes of today's events very closely.

2013-2-22: Site Outage Update

We are experiencing issues with the database that powers, which is causing intermittent outages and latency issues. We will continue working to bring Coursera back into a stable state. Students and staff should still be able to access

2013-2-22: Site Outage Update

Update: We now have back up (as of around 11AM PST), but we have disabled the course explorer interface and are actively investigating high latency issues.

2013-2-22: Site Outage Update

We were able to restore service to (the class platform) at around 9 AM PST. We are still experiencing an outage / high latency issues on (the course explorer and account dashboard) and are working to bring those back up.

2013-02-22 : Site Outage

We are currently experiencing an outage on and We are investigating the issue and hope to have it resolved soon.