On March 24, 2021 at 8:02 AM PDT, an invalid PHP configuration was deployed to the platform. After observing increased error rates, the deployment was stopped before full rollout and reverted, with remediation efforts beginning immediately for impacted sites. This invalid configuration caused elevated error rates for about 9% of sites on the platform. All sites were fully remediated by 3:39 PM PDT.
Pantheon is implementing improvements to its internal processes, infrastructure, and tooling to prevent similar incidents from happening again in the future. Additionally, improvements to our ability to more quickly detect and recover from such incidents have been identified and are being worked on.