I'm going to point you at the S3A troubleshooting docs, where we try to match error messages to root causes, though "bad request" is a broad issue -one AWS don't provide details on for security reasons   https://hadoop.apache.org/docs/r2.8.0/hadoop-aws/tools/hadoop-aws/index.html#Troubleshooting_S3A   for a us-west-2 endpoint you can/should just stick with the main endpoint. If you do change, you may have to worry about s3 signing algorithms. Depending on the specific version of CDH you are using that's  a hadoop config option; for the older versions, it's a JVM property which is tricky to propagate over hadoop application deployments.    Summary: * try to just stick to the central endpoint * if you need to use a "V4 only endpoint", try and use the most recent version of CDH you can and use the fs.s3a.signing.algorithm option ... View more