Tonight's Kiln outage was resolved shortly after we posted.
An in-depth post-mortem will be posted tomorrow, but the short version is that a change to our default Kiln generation caused our web servers to begin returning HTTP 500 errors on an empty Host: header. Our load balancers use simple OPTIONS HTTP 1.0 checks to monitor our servers' health. When this change was effected, our load balancers declared the servers dead and users began receiving HTTP 503 errors. We've modified the health checks to pass along a Host: header and will analyze tomorrow how this was overlooked in our testing.
We apologize for the interruption. If this got in your way, please contact us and we'll make it right.
