Note: All CDH and Cloudera Manager hosts that make up a logical cluster need to run on the same major OS release to be covered by Cloudera Support.

Cloudera Manager supports the following 64-bit operating systems:

• RHEL-compatible
  • Red Hat Enterprise Linux and CentOS, 64-bit (+ SELinux mode in available versions)
    • 5.7
    • 5.10
    • 6.4
    • 6.5
    • 6.6
    • 6.7
    • 7.1
    • 7.2
  • Oracle Enterprise Linux (OEL) with Unbreakable Enterprise Kernel (UEK), 64-bit
    • 5.7 (UEK R2)
    • 5.10
    • 5.11
    • 6.4 (UEK R2)
    • 6.5 (UEK R2, UEK R3)
    • 6.6 (UEK R3)
    • 6.7 (UEK R3)
    • 7.1
    • 7.2
    Important: Cloudera supports RHEL 7 with the following limitations:

  • Only RHEL 7.2 and 7.1 are supported. RHEL 7.0 is not supported.
  • RHEL 7.1 is only supported with CDH 5.5 and higher.
  • RHEL 7.2 is only supported with CDH 5.7 and higher.
  • Only new installations of RHEL 7.2 and 7.1 are supported by Cloudera. For upgrades to RHEL 7.1 or 7.2, contact your OS vendor and see Does Red Hat support upgrades between major versions of Red Hat Enterprise Linux?
• SLES - SUSE Linux Enterprise Server 11, Service Pack 4, 64-bit is supported by CDH 5.7 and higher. Service Packs 2 and 3 are supported by CDH 5.0 through CDH 5.6. Service Pack 1 is not supported by CDH 5, only by CDH 4. Hosts running Cloudera Manager Agents must use SUSE Linux Enterprise Software Development Kit 11 SP1.
• Debian - Wheezy 7.0, 7.1, and 7.8, 64-bit. (Squeeze 6.0 is only supported by CDH 4.)
• Ubuntu - Trusty 14.04 (LTS) and Precise 12.04 (LTS), 64-bit. (Lucid 10.04 is only supported by CDH 4.)

  Note:

• Cloudera Enterprise is supported on platforms with Security-Enhanced Linux (SELinux) enabled. Cloudera is not responsible for policy support nor policy enforcement. If you experience issues with SELinux, contact your OS provider.
• CDH 5.7 DataNode hosts with EMC® DSSD™ D5™ are supported by RHEL 6.6, 7.1, and 7.2. CDH 5.6 DataNode hosts with EMC® DSSD™ D5™ are only supported by RHEL 6.6.

The version of Oracle JDK supported by Cloudera Manager depends on the version of CDH being managed. The following table lists the JDK versions supported on a Cloudera Manager 5.8 cluster running the latest CDH 5. For more information see CDH and Cloudera Manager Supported JDK Versions.

Cloudera Manager can install Oracle JDK 1.7.0_67 during installation and upgrade. If you prefer to install the JDK yourself, follow the instructions in Java Development Kit Installation.

Cloudera Manager requires several databases. The Cloudera Manager Server stores information about configured services, role assignments, configuration history, commands, users, and running processes in a database of its own. You must also specify a database for the Activity Monitor and Reports Manager roles.

  Important: When processes restart, the configuration for each of the services is redeployed using information that is saved in the Cloudera Manager database. If this information is not available, your cluster will not start or function correctly. You must therefore schedule and maintain regular backups of the Cloudera Manager database to recover the cluster in the event of the loss of this database.

The database you use must be configured to support UTF8 character set encoding. The embedded PostgreSQL database that is installed when you follow Installation Path A - Automated Installation by Cloudera Manager (Non-Production Mode) automatically provides UTF8 encoding. If you install a custom database, you may need to enable UTF8 encoding. The commands for enabling UTF8 encoding are described in each database topic under Cloudera Manager and Managed Service Datastores.

After installing a database, upgrade to the latest patch version and apply any other appropriate updates. Available updates may be specific to the operating system on which it is installed.

Cloudera Manager and its supporting services can use the following databases:

• MariaDB 5.5
• MySQL - 5.1, 5.5, 5.6, and 5.7
• Oracle 11gR2 and 12c
    Note: When installing a JDBC driver, only the ojdbc6.jar file is supported for both Oracle 11g R2 and Oracle 12c; the ojdbc7.jar file is not supported.
• PostgreSQL - 8.1, 8.3, 8.4, 9.1, 9.2, 9.3, 9.4

Cloudera supports the shipped version of MariaDB, MySQL and PostgreSQL for each supported Linux distribution. Each database is supported for all components in Cloudera Manager and CDH subject to the notes in CDH 4 Supported Databases and CDH 5 Supported Databases.

The following components are supported by Transport Layer Security (TLS):

To configure TLS security for the Cloudera Manager Server and Agents, see Configuring TLS Security for Cloudera Manager.

The hosts in a Cloudera Manager deployment must satisfy the following networking and security requirements:

• Cluster hosts must have a working network name resolution system and correctly formatted /etc/hosts file. All cluster hosts must have properly configured forward and reverse host resolution through DNS. The /etc/hosts files must
  • Contain consistent information about hostnames and IP addresses across all hosts
  • Not contain uppercase hostnames
  • Not contain duplicate IP addresses

  Also, do not use aliases, either in /etc/hosts or in configuring DNS. A properly formatted /etc/hosts file should be similar to the following example:

  127.0.0.1    localhost.localdomain   localhost
  192.168.1.1     cluster-01.example.com  cluster-01
  192.168.1.2     cluster-02.example.com  cluster-02
  192.168.1.3     cluster-03.example.com  cluster-03 

• In most cases, the Cloudera Manager Server must have SSH access to the cluster hosts when you run the installation or upgrade wizard. You must log in using a root account or an account that has password-less sudo permission. For authentication during the installation and upgrade procedures, you must either enter the password or upload a public and private key pair for the root or sudo user account. If you want to use a public and private key pair, the public key must be installed on the cluster hosts before you use Cloudera Manager.

  Cloudera Manager uses SSH only during the initial install or upgrade. Once the cluster is set up, you can disable root SSH access or change the root password. Cloudera Manager does not save SSH credentials, and all credential information is discarded when the installation is complete. For more information, see Permission Requirements for Package-based Installations and Upgrades of CDH.

• If single user mode is not enabled, the Cloudera Manager Agent runs as root so that it can make sure the required directories are created and that processes and files are owned by the appropriate user (for example, the hdfs and mapred users).
• No blocking is done by Security-Enhanced Linux (SELinux).
    Note: Cloudera Enterprise is supported on platforms with Security-Enhanced Linux (SELinux) enabled. Cloudera is not responsible for policy support nor policy enforcement. If you experience issues with SELinux, contact your OS provider.
• IPv6 must be disabled.
• Multihoming CDH or Cloudera Manager is not supported outside specifically certified Cloudera partner appliances. Cloudera finds that current Hadoop architectures combined with modern network infrastructures and security practices remove the need for multihoming. Multihoming, however, is beneficial internally in appliance form factors to take advantage of high-bandwidth InfiniBand interconnects.

  Although some subareas of the product may work with unsupported custom multihoming configurations, there are known issues with multihoming. In addition, unknown issues may arise because multihoming is not covered by our test matrix outside the Cloudera-certified partner appliances.

• No blocking by iptables or firewalls; port 7180 must be open because it is used to access Cloudera Manager after installation. Cloudera Manager communicates using specific ports, which must be open.
• For RHEL and CentOS, the /etc/sysconfig/network file on each host must contain the hostname you have just set (or verified) for that host.
• Cloudera Manager and CDH use several user accounts and groups to complete their tasks. The set of user accounts and groups varies according to the components you choose to install. Do not delete these accounts or groups and do not modify their permissions and rights. Ensure that no existing systems prevent these accounts and groups from functioning. For example, if you have scripts that delete user accounts not in a whitelist, add these accounts to the list of permitted accounts. Cloudera Manager, CDH, and managed services create and use the following accounts and groups:

Table 2. Users and Groups

Component (Version)	Unix User ID	Groups	Notes
Cloudera Manager (all versions)	cloudera-scm	cloudera-scm	Cloudera Manager processes such as the Cloudera Manager Server and the monitoring roles run as this user. The Cloudera Manager keytab file must be named cmf.keytab since that name is hard-coded in Cloudera Manager.   Note: Applicable to clusters managed by Cloudera Manager only.
Apache Accumulo (Accumulo 1.4.3 and higher)	accumulo	accumulo	Accumulo processes run as this user.
Apache Avro			No special users.
Apache Flume (CDH 4, CDH 5)	flume	flume	The sink that writes to HDFS as this user must have write privileges.
Apache HBase (CDH 4, CDH 5)	hbase	hbase	The Master and the RegionServer processes run as this user.
HDFS (CDH 4, CDH 5)	hdfs	hdfs, hadoop	The NameNode and DataNodes run as this user, and the HDFS root directory as well as the directories used for edit logs should be owned by it.
Apache Hive (CDH 4, CDH 5)	hive	hive	The HiveServer2 process and the Hive Metastore processes run as this user. A user must be defined for Hive access to its Metastore DB (for example, MySQL or Postgres) but it can be any identifier and does not correspond to a Unix uid. This is javax.jdo.option.ConnectionUserName in hive-site.xml.
Apache HCatalog (CDH 4.2 and higher, CDH 5)	hive	hive	The WebHCat service (for REST access to Hive functionality) runs as the hive user.
HttpFS (CDH 4, CDH 5)	httpfs	httpfs	The HttpFS service runs as this user. See HttpFS Security Configuration for instructions on how to generate the merged httpfs-http.keytab file.
Hue (CDH 4, CDH 5)	hue	hue	Hue services run as this user.
Cloudera Impala (CDH 4.1 and higher, CDH 5)	impala	impala, hive	Impala services run as this user.
Apache Kafka (Cloudera Distribution of Kafka 1.2.0)	kafka	kafka	Kafka services run as this user.
Java KeyStore KMS (CDH 5.2.1 and higher)	kms	kms	The Java KeyStore KMS service runs as this user.
Key Trustee KMS (CDH 5.3 and higher)	kms	kms	The Key Trustee KMS service runs as this user.
Key Trustee Server (CDH 5.4 and higher)	keytrustee	keytrustee	The Key Trustee Server service runs as this user.
Kudu	kudu	kudu	Kudu services run as this user.
Llama (CDH 5)	llama	llama	Llama runs as this user.
Apache Mahout			No special users.
MapReduce (CDH 4, CDH 5)	mapred	mapred, hadoop	Without Kerberos, the JobTracker and tasks run as this user. The LinuxTaskController binary is owned by this user for Kerberos.
Apache Oozie (CDH 4, CDH 5)	oozie	oozie	The Oozie service runs as this user.
Parquet			No special users.
Apache Pig			No special users.
Cloudera Search (CDH 4.3 and higher, CDH 5)	solr	solr	The Solr processes run as this user.
Apache Spark (CDH 5)	spark	spark	The Spark History Server process runs as this user.
Apache Sentry (CDH 5.1 and higher)	sentry	sentry	The Sentry service runs as this user.
Apache Sqoop (CDH 4, CDH 5)	sqoop	sqoop	This user is only for the Sqoop1 Metastore, a configuration option that is not recommended.
Apache Sqoop2 (CDH 4.2 and higher, CDH 5)	sqoop2	sqoop, sqoop2	The Sqoop2 service runs as this user.
Apache Whirr			No special users.
YARN (CDH 4, CDH 5)	yarn	yarn, hadoop	Without Kerberos, all YARN services and applications run as this user. The LinuxContainerExecutor binary is owned by this user for Kerberos.
Apache ZooKeeper (CDH 4, CDH 5)	zookeeper	zookeeper	The ZooKeeper processes run as this user. It is not configurable.