• The installed JDK must be a supported version as documented in CDH and Cloudera Manager Supported JDK Versions.
• The same version of the Oracle JDK must be installed on each cluster host.
• The JDK must be installed at /usr/java/jdk-version.

  Important:

• The RHEL-compatible and Ubuntu operating systems supported by Cloudera Enterprise all use AES-256 encryption by default for tickets. To support AES-256 bit encryption in JDK versions lower than 1.8u161, you must install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy File on all cluster and Hadoop user machines. Cloudera Manager can automatically install the policy files, or you can install them manually. For JCE Policy File installation instructions, see the README.txt file included in the jce_policy-x.zip file. JDK 1.8u161 and higher enable unlimited strength encryption by default, and do not require policy files.
• On SLES platforms, do not install or try to use the IBM Java version bundled with the SLES distribution. CDH does not run correctly with that version.

The Oracle JDK installer is available both as an RPM-based installer for RPM-based systems, and as a .tar.gz file. These instructions are for the .tar.gz file.

1. Download the .tar.gz file for one of the 64-bit supported versions of the Oracle JDK from Java SE 8 Downloads. (This link is correct at the time of writing, but can change.)
     Note: If you want to download the JDK directly using a utility such as wget, you must accept the Oracle license by configuring headers, which are updated frequently. Blog posts and Q&A sites can be a good source of information on how to download a particular JDK version using wget.
2. Extract the JDK to /usr/java/jdk-version. For example:

   tar xvfz /path/to/jdk-8u<update_version>-linux-x64.tar.gz -C /usr/java/

3. Repeat this procedure on all cluster hosts. After you have finished, continue to Step 4: Install CDH Packages.