Amazon EMR
Amazon EMR Release Guide

What's New?

This topic covers features and issues resolved in the current release of Amazon EMR. These release notes are also available on the Release 5.21.0 Tab, along with the application versions, component versions, and available configuration classifications for this release.

Subscribe to the RSS feed for Amazon EMR release notes at to receive updates when a new Amazon EMR release version is available.

For earlier release notes going back to release version 4.2.0, see Amazon EMR What's New History.

Release 5.21.0 (Latest)

New Amazon EMR release versions are made available in different regions over a period of several days, beginning with the first region on the initial release date. The latest release version may not be available in your region during this period.

The following release notes include information for Amazon EMR release version 5.21.0. Changes are relative to 5.20.0.

Initial release date: February 18, 2019


  • Flink 1.7.0

  • Presto 0.215

  • AWS SDK for Java 1.11.479

Changes, Enhancements, and Resolved Issues

Known Issues

  • Tez

    • When you connect to the Tez UI at http://MasterDNS:8080/tez-ui through an SSH connection to the cluster master node, the error "Adapter operation failed - Timeline server (ATS) is out of reach. Either it is down, or CORS is not enabled" appears, or tasks unexpectedly show N/A.

      This is caused by the Tez UI making requests to the YARN Timeline Server using localhost rather than the host name of the master node. As a workaround, a script is available to run as a bootstrap action or step. The script updates the host name in the Tez configs.env file. For more information and the location of the script, see the Bootstrap Instructions.

On this page: