Amazon acknowledged that the system failure was exacerbated by the co-dependencies its various services have on one another. The company had been trying to add capacity to its Amazon Kinesis service that customers use to process real-time data including video, audio and application logs. To resolve the issue, Amazon needed to restart a piece of its system it described as “many thousands of servers,” a lengthy process that had to be done gradually. But because other Amazon cloud services rely on Kinesis, including its Cognito authentication offering, they failed as well.