At approximately 15:45 UTC on 14 June 2021, we saw intermittent errors when applications attempted to resolve hostnames via DNS. DNS lookups became reliable again at 23:39 UTC.
During this period, services remained online and the majority of workloads completed successfully. However, some customers may have noticed intermittent errors across all aspects of their account including the API, sends, imports and Programs.
After investigation, we found DNS errors were occurring in applications hosted on a particular server. We’re continuing our work to understand why this server developed a fault. As all our applications are hosted on multiple servers, all other instances continued to work as normal.
Our timeline for rectifying this issue was (times stated in UTC):
Our applications are hosted on a cloud native service which aims to provide a reliable hosting environment. However, during this incident a component in this environment failed to work as expected. In conjunction with our cloud supplier, we’ll continue an investigation to identify the events leading to the server failure. Our current action items are: