Thursday July 22, 7:50 AM - 9:00 AM UTC
iOS devices were not available in the US-West Datacenter
We introduced a new health check, adding more load to the process of re-signing applications. When we deployed a new release the added load brought down the machines hosting the iOS devices.
The host machines were restarted and the re-signer services were re-deployed.
We are improving the application re-signing process to reduce the load on the host machines and added more monitoring to spot extra loads on the re-signers services earlier on.