> the software initiating maintenance events had a specific bug, allowing it to deschedule multiple independent software clusters at once, crucially even if those clusters were in different physical locations.
> The network ran normally for a short period - several minutes - after the control plane had been descheduled. After this period, BGP routing between specific impacted physical locations was withdrawn, resulting in the significant reduction in network capacity observed by our services and users, and the inaccessibility of some Google Cloud regions.