title: AWS EMR writing to KMS Encrypted S3 Parquet Files
body: <p>I am using AWS EMR 5.0, Spark 2.0, Scala 2.11, S3 - encrypted with KMS(SSE-custom key), Parquet files.     I can read the encrypted parquet files - no problem.   However, when I write, I get a warning.   Simplified code looks like:</p>
  
  <pre><code>val headerHistory = spark.read.parquet("s3://&lt;my bucket&gt;/header_1473640645")
  headerHistory.write.parquet("s3://&lt;my bucket&gt;/temp/")
  </code></pre>
  
  <p>but generates a warning:</p>
  
  <p>16/09/15 13:11:11 WARN S3V4AuthErrorRetryStrategy: Attempting to re-send the request to my bucket.s3.amazonaws.com with AWS V4 authentication. To avoid this warning in the future, please use region-specific endpoint to access buckets located in regions that require V4 signing.</p>
  
  <p>Do I need an option?  Do I need to set some environment variable?</p>