The following was posted from Canvas Technical Support on Monday May 16th 12:17 p.m.
Users have unable to access and view documents via DocViewer, primarily through SpeedGrader. Available resources for the service were not enough to process requests for the number of users accessing DocViewer files at the time. Additional resources were added throughout the morning until service was consistent for users again.
Manually adding additional resources to handle user load, along with updating configurations within our new auto-scaling system for DocViewer allowed the service to run as it should once again. With other services also moving to this new system, we are working on providing better documentation, training, and guidance to engineers across various services as they do so. This will include information on how to better plan for expected usage and provide the correct number of resources to handle user requests across each.
We understand the importance our DocViewer has on Canvas functionality and the impact this caused for users trying to access the service. We are working to put safeguards in place to prevent service interruption from happening again through DocViewer and we apologize for the inconvenience this caused.