Add configuration option to disable "Expect: 100-continue" header for S3 streaming operations

[bhoradc]

Describe the feature

Java SDK currently forces the Expect: 100-continue header on all putObject and uploadPart requests via StreamingRequestInterceptor. This overrides any HttpClient configuration that attempts to disable this header. We need a SDK-level configuration option to control whether the Expect: 100-continue header is added to streaming requests.

Use Case

The Hadoop S3A connector added fs.s3a.connection.expect.continue to disable expect-continue for rare cases where network/proxy failures before CONTINUE response cause thread hangs. However, SDK's StreamingRequestInterceptor explicitly sets the header, bypassing the HttpClient configuration. Need SDK-level control for this emergency option.

Proposed Solution

No response

Other Information

This feature request originated from discussion in GitHub issue #6459 (comment)

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS Java SDK version used

2.32.23

JDK version used

17

Operating System and version

Amazon Linux