Just read the AWS IoT document. I am very curious about the design of its message broker:
The topic namespace is isolated for each AWS account and region pair. For example, the Sensor/temp/room1 topic for an AWS account is independent from the "Sensor/temp/room1" topic for another AWS account. This is true of regions, too. The "Sensor/temp/room1" topic in the same AWS account in us-east-1 is independent from the same topic in us-west-2. AWS IoT does not support sending and receiving messages across AWS accounts and regions.
Why AWS separates the access of the message broker? Wouldn't it be convenient if the message is accessible cross multiple regions?
What is the benefit of making message broker region-independent?