This is a short placeholder blog and will be replaced with a full post-mortem and disclosure of what happened today.
For about 30 minutes today, visitors to Cloudflare sites received 502 errors caused by a massive spike in CPU utilization on our network. This CPU spike was caused by a bad software deploy that was rolled back. Once rolled back the service returned to normal operation and all domains using Cloudflare returned to normal traffic levels.
This was not an attack (as some have speculated) and we are incredibly sorry that this incident occurred. Internal teams are meeting as I write performing a full post-mortem to understand how this occurred and how we prevent this from ever occurring again.