#March 20: DFW capacity, again (07:20UTC)

The capacity we provisioned in DFW but two days earlier was slurped up in short order, so we were back to machines on some hosts being unable to start due to resource gates. With the popularity of the region, we found our placement would concentrate new machines onto the few best hosts at any given moment, which would itself create new bursts of start failures. In response to this incident we once again brought new hosts online, alongside improving our placement logic to better handle this case.