Aws-sdk-java: sts client should be defaulting to regional endpoint

[zhangzhx]

As STS is recommended to use regional endpoint, the STS client builder should be defaulting to use regional endpoint instead of the global one https://sts.amazonaws.com.

[debora-ito]

Hi @zhangzhx, using regional STS endpoints is recommended, but the default still is the global endpoint. Check the "Writing Code to Use AWS STS Regions" section in the docs you linked to learn more about it.

Closing this, feel free to reach out if you have further questions.

[joelthompson]

For those who find this later, as of 1.11.618, it's possible to change the default behavior using either an environment variable or a profile config option. See https://github.com/aws/aws-sdk-java/blob/master/aws-java-sdk-sts/src/main/java/com/amazonaws/services/securitytoken/RegionalEndpointsOptionResolver.java