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The recommended tool for installing Cloudera Enterprise

This download installs Cloudera Enterprise or Cloudera Express.


Cloudera Enterprise requires a license; however, when installing Cloudera Express you will have the option to unlock Cloudera Enterprise features for a free 60-day trial.


Once the trial has concluded, the Cloudera Enterprise features will be disabled until you obtain and upload a license.


Supported Operating Systems


Cloudera Manager supports the following operating systems:

  • RHEL-compatible systems
    • Red Hat Enterprise Linux and CentOS 5.7, 64-bit
    • Red Hat Enterprise Linux and CentOS 6.4, 64-bit
    • Red Hat Enterprise Linux and CentOS 6.4 in SE Linux Mode
    • Red Hat Enterprise Linux and CentOS 6.5, 64-bit
    • Oracle Enterprise Linux 5.6 (UEK R2), 64-bit
    • Oracle Enterprise Linux 6.4 (UEK R2), 64-bit
    • Oracle Enterprise Linux 6.5 (UEK R2, UEK R3), 64-bit
  • SLES - SUSE Linux Enterprise Server 11, 64-bit. Service Pack 2 or later is required for CDH 5 and Service Pack 1 or later is required for CDH 4. To use the embedded PostgreSQL database that is installed when you follow Installation Path A - Automated Installation by Cloudera Manager, the Updates repository must be active. The SUSE Linux Enterprise Software Development Kit 11 SP1is required on hosts running the Cloudera Manager Agents.
  • Debian - Debian 7.0 and 7.1, 6.0 (deprecated), 64-bit
  • Ubuntu - Ubuntu 12.04, 10.04 (deprecated), 64-bit


  • Debian 6.0 and Ubuntu 10.04 are supported only for CDH 4.
  • Using the same version of the same operating system on all cluster hosts is strongly recommended.




Selected tab: supportedoperatingsystems

Supported JDK Versions


Cloudera Manager supports Oracle JDK 1.7.0_55 when it's managing CDH 5.x and Oracle JDK 1.6.0_31 and 1.7.0_55 when it's managing CDH 4.x. Cloudera Manager supports Oracle JDK 1.7.0_55 when it's managing both CDH 4.x and CDH 5.x clusters. Oracle JDK 1.6.0_31 and 1.7.0_55 can be installed during the installation and upgrade. For further information, see Java Development Kit Installation.




Selected tab: supportedjdkversions

Supported Browsers


The Cloudera Manager Admin Console, which you use to install, configure, manage, and monitor services, supports the following browsers:

  • Firefox 24 or 31
  • Google Chrome
  • Internet Explorer 9 or later
  • Safari 5 or later



Selected tab: supportedbrowsers

Supported Databases


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 management services.


The database you choose to 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 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's section under Cloudera Manager and Managed Service Databases.


After installing a database, upgrade to the latest patch version and apply any other appropriate updates. The 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:

  • MySQL - 5.0, 5.1, 5.5, and 5.6
  • Oracle 11gR2
  • PostgreSQL - 8.4, 9.1, and 9.2


For information about the databases supported by CDH, see CDH 4 Supported Databases and CDH 5 Supported Databases.


Selected tab: supporteddatabases

Supported CDH and Managed Service Versions


The following versions of CDH and managed services are supported:

Warning: Cloudera Manager 5 does not support CDH 3 and you cannot upgrade Cloudera Manager 4 to Cloudera Manager 5 if you have a cluster running CDH 3. Therefore, to upgrade CDH 3 clusters to CDH 4 using Cloudera Manager you must use Cloudera Manager 4.

  • CDH 4 and CDH 5. The latest released versions of CDH 4 and CDH 5 are strongly recommended. For information on CDH 4 requirements, see CDH 4 Requirements and Supported Versions. For information on CDH 5 requirements, see CDH 5 Requirements and Supported Versions.
  • Cloudera Impala - Cloudera Impala is included with CDH 5. Cloudera Impala 1.2.1 with CDH 4.1.0 or later. For further information on Cloudera Impala requirements with CDH 4, see Cloudera Impala Requirements.
  • Cloudera Search - Cloudera Search is included with CDH 5. Cloudera Search 1.2.0 with CDH 4.6.0. For further information on Cloudera Search requirements with CDH 4, see Cloudera Search Requirements.
  • Apache Spark - 0.90 or later with CDH 4.4.0 or later.
  • Apache Accumulo - 1.4.3 with CDH 4.3.0, 1.4.4 with CDH 4.5.0, and 1.6.0 with CDH 4.6.0.

For more information, see the Cloudera Product Compatibility Matrix.



Selected tab: supportedcdhandmanagedserviceversions

Resource Requirements


Cloudera Manager requires resources of the following types:

  • Disk Space
    • Cloudera Manager Server
      • 5 GB on the partition hosting /var.
      • 500 MB on the partition hosting /usr.
      • For parcels, the space required depends on the number of parcels you download to the Cloudera Manager Server and distribute to Agent hosts. You can download multiple parcels of the same product, of different versions and builds. If you are managing multiple clusters, there will be only one parcel of a given product/version/build/distribution downloaded on the Cloudera Manager Server—not one per cluster. In the local parcel repository on the Cloudera Manager Server the approximate sizes of the various parcels are as follows:
        • CDH 4.6 - ~700 MB per parcel, CDH 5 - ~1 GB per parcel
        • Impala - ~200 MB per parcel
        • Solr - ~ 400 MB per parcel
    • Cloudera Management Service - The Host Monitor and Service Monitor databases are stored on the partition hosting /var. Ensure that you have at least 20 GB available on this partition.For further information, see Data Storage for Monitoring Data.
    • Agents - On Agent hosts each unpacked parcel requires about three times the space of the downloaded parcel on the Cloudera Manager Server. By default unpacked parcels are located in /opt/cloudera/parcels.
  • RAM - 4 GB is appropriate for most cases, and is required when using Oracle databases. 2 GB may be sufficient for non-Oracle deployments involving fewer than 100 hosts. However, if you want to run the Cloudera Manager Server on a machine with 2 GB of RAM, you must tune down its maximum heap size (by modifying -Xmx in /etc/default/cloudera-scm-server). Otherwise the kernel may kill the Server for consuming too much RAM.
  • Python - Cloudera Manager uses Python. All supported operating systems contain a Python version 2.4 or higher. Cloudera Manager and CDH 4 require at least Python 2.4, but Hue in CDH 5 requires Python 2.6 or 2.7.




Selected tab: resourcerequirements


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 host names and addresses across all hosts. A properly formatted /etc/hosts should be similar to the following example: localhost.localdomain localhost cluster-01 cluster-02 cluster-03

    The /etc/hosts file must not have duplicate IP addresses.
  • 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 your 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 once the installation is complete. For further information, see Permission Requirements.

  • 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 andmapred users).
  • No blocking by Security-Enhanced Linux (SELinux).
  • Disable Ipv6 on all hosts.
  • No blocking by iptables or firewalls; make sure port 7180 is open because it is the port used to access Cloudera Manager after installation. Cloudera Manager communicates using specific ports, which must be open. See Configuring Ports for Cloudera Manager.
  • For RedHat and CentOS, make sure the/etc/sysconfig/network file on each system contains the hostname you have just set (or verified) for that system.
  • Cloudera Manager and CDH use several user accounts and groups to complete their tasks. The set of user accounts and groups varies according to which components you choose to install. Do not delete these accounts or groups and do not modify their permissions and rights. Ensure no existing systems obstruct the functioning of these accounts and groups. For example, if you have scripts that delete user accounts not in a white-list, add these accounts to the list of permitted accounts. Cloudera Manager, CDH, and managed services create and use the following accounts and groups:

    Account Type Product


    User and group Cloudera Manager


    User and group CDH 4, CDH 5


    Group CDH 4, CDH 5


    User and group CDH 4, CDH 5


    User and group. Must also be a member of the hadoop group. CDH 4, CDH 5


    User and group CDH 4, CDH 5


    User and group CDH 4, CDH 5


    User and group CDH 4, CDH 5


    User and group. Must also be member of the hdfs and hivegroups. CDH 4.1 or later, CDH 5


    User and group CDH 5


    User and group. Must also be a member of the hadoop group. CDH 4, CDH 5


    User and group CDH 4, CDH 5


    User and group CDH 4.3 and later, CDH 5


    User and group Spark, CDH 5


    User and group CDH 4, CDH 5


    User. Must be member of the sqoopgroup. CDH 4.2 and later, CDH 5


    User and group CDH 4, CDH 5


    User and group CDH 4, CDH 5


Selected tab: networkingandsecurityrequirements
Selected tab: systemrequirements

Known Issues and Workarounds in Cloudera Manager 5.1.1

The following sections describe the current known issues in Cloudera Manager 5.1.1.


Could not find a healthy host with CDH5 on it to create HiveServer2 error during upgrade

When upgrading from CDH 4 to CDH 5, if no parcel is active then the error message "Could not find a healthy host with CDH5 on it to create HiveServer2" displays. This can happen when transitioning from packages to parcels, or if you explicitly deactivate the CDH 4 parcel (which is not necessary) before upgrade.

Workaround: Wait 30 seconds and retry the upgrade.

AWS Installation wizard requires Java 7u45 to be installed on Cloudera Manager Server host

Cloudera Manager 5.1 installs Java 7u55 by default. However, the AWS installation wizard does not work with Java 7u55 due to a bug in the jClouds version packaged with Cloudera Manager.


  1. Stop the Cloudera Manager Server.

    $ sudo service cloudera-scm-server stop

  2. Uninstall Java 7u55 from the Cloudera Manager Server host.
  3. Install Java 7u45 (which you can download from on the Cloudera Manager Server host.
  4. Start the Cloudera Manager Server.

    $ sudo service cloudera-scm-server start

  5. Run the AWS installation wizard.

  Note: Due to a bug in Java 7u45 (, SSL connections between the Cloudera Manager Server and Cloudera Manager Agents and between the Cloudera Management Service and CDH processes break intermittently. If you do not have SSL enabled on your cluster, there is no impact.

The Spark History Server does not start when Kerberos authentication is enabled.

The Spark History Server does not start when managed by a Cloudera Manager 5.1 instance when Kerberos authentication is enabled.


  1. Go to the Spark service.
  2. Expand the Service-Wide > Advanced category.
  3. Add the following configuration to the History Server Environment Advanced Configuration Snippet property:

    SPARK_HISTORY_OPTS=-Dspark.history.kerberos.enabled=true \
    -Dspark.history.kerberos.principal=principal \

where principal is the name of the Kerberos principal to use for the History Server, and keytab is the path to the principal's keytab file on the local filesystem of the host running the History Server.

Spurious warning on Accumulo 1.6 gateway hosts

When using the Accumulo shell on a host with only an Accumulo 1.6 Service gateway role, users will receive a warning about failing to create the directory/var/log/accumulo. The shell works normally otherwise.

Workaround: The warning is safe to ignore.

Accumulo 1.6 service log aggregation and search does not work

Cloudera Manager log aggregation and search features are incompatible with the log formatting needed by the Accumulo Monitor. Attempting to use either the "Log Search" diagnostics feature or the log file link off of an individual service role's summary page will result in empty search results.

Severity: High

Workaround: Operators can use the Accumulo Monitor to see recent severe log messages. They can see recent log messages below the WARNING level via a given role's process page and can inspect full logs on individual hosts by looking in /var/log/accumulo.

Cloudera Manager incorrectly sizes Accumulo Tablet Server max heap size after 1.4.4-cdh4.5.0 to 1.6.0-cdh4.6.0 upgrade

Because the upgrade path from Accumulo 1.4.4-cdh4.5.0 to 1.6.0-cdh4.6.0 involves having both services installed simultaneously, Cloudera Manager will be under the impression that worker hosts in the cluster are oversubscribed on memory and attempt to downsize the max heap size allowed for 1.6.0-cdh4.6.0 Tablet Servers.

Severity: High

Workaround: Manually verify that the Accumulo 1.6.0-cdh4.6.0 Tablet Server max heap size is large enough for your needs. Cloudera recommends you set this value to the sum of 1.4.4-cdh4.5.0 Tablet Server and Logger heap sizes.

If a NodeManager that is used as ApplicationMaster is decommissioned, YARN jobs will hang

Jobs can hang on NodeManager decommission due to a race condition when continuous scheduling is enabled.


  1. Go to the YARN service.
  2. Expand the ResourceManager Default Group > Resource Management category.
  3. Uncheck the Enable Fair Scheduler Continuous Scheduling checkbox.
  4. Click Save Changes to commit the changes.
  5. Restart the YARN service.

The YARN property ApplicationMaster Max Retries has no effect in CDH 5

The issue arises because was replaced with


  1. Add the following to ResourceManager Advanced Configuration Snippet for yarn-site.xml, replacing MAX_ATTEMPTS with the desired maximum number of attempts:


  2. Restart the ResourceManager(s) to pick up the change.

Cluster CDH version not configured correctly for package installs

If you have installed CDH as a package, after the install make sure that the cluster CDH version matches the package CDH version. If the cluster CDH version does not match the package CDH version, Cloudera Manager will incorrectly enable and disable service features based on the cluster's configured CDH version.


Manually configure the cluster CDH version to match the package CDH version. Click ClusterName > Actions > Configure CDH Version. In the dialog, Cloudera Manager displays the installed CDH version, and asks for confirmation to configure itself with the new version.

Accumulo installations using LZO do not indicate dependence on the GPL Extras parcel

Accumulo 1.6 installations that use LZO compression functionality do not indicate that LZO depends on the GPL Extras parcel. When Accumulo is configured to use LZO, Cloudera Manager has no way to track that the Accumulo service now relies on the GPL Extras parcel. This prevents Cloudera Manager from warning administrators before they remove the parcel while Accumulo still requires it for proper operation.

Workaround: Check your Accumulo 1.6 service for the configuration changes mentioned in the Cloudera documentation for using Accumulo with CDH prior to removing the GPL Extras parcel. If the parcel is mistakenly removed, reinstall it and restart the Accumulo 1.6 service.

NodeManager Container Memory not imported to YARN correctly

When MapReduce configurations are imported to YARN, the property yarn.nodemanager.resource.memory-mb may not be set correctly for optimal YARN performance.

Workaround: Configure this property manually after running the import, then restart YARN.

Clients of the JobHistory Server Admin Interface Require Advanced Configuration Snippet

Clients of the JobHistory server administrative interface, such as the mapred hsadmin tool, may fail to connect to the server when run on hosts other than the one where the JobHistory server is running.

Workaround: Add the following to both the MapReduce Client Advanced Configuration Snippet for mapred-site.xml and the Cluster-wide Advanced Configuration Snippet for core-site.xml, replacing JOBHISTORY_SERVER_HOST with the hostname of your JobHistory server:


Created pools are not preserved when Dynamic Resource Pools page is used to configure YARN or Impala

Pools created on demand are not preserved when changes are made using the Dynamic Resource Pools page. If the Dynamic Resource Pools page is used to configure YARN and/or Impala services in a cluster, it is possible to specify pool placement rules that create a pool if one does not already exist. If changes are made to the configuration using this page, pools created as a result of such rules are not preserved across the configuration change.

Workaround: Submit the YARN application or Impala query as before, and the pool will be created on demand once again.

Reset non-default HDFS File Block Storage Location Timeout value after upgrade from CDH 4 to CDH 5

During an upgrade from CDH 4 to CDH 5, if the HDFS File Block Storage Locations Timeout was previously set to a custom value, it will now be set to 10 seconds or the custom value, whichever is higher. This is required for Impala to start in CDH 5, and any value under 10 seconds is now a validation error. This configuration is only emitted for Impala and no services should be adversely impacted.

Workaround: None.

If installing CDH 4 packages, the Impala 1.3.0 option does not work because Impala 1.3 is not yet released for CDH 4.

If installing CDH 4 packages, the Impala 1.3.0 option listed in the install wizard does not work because Impala 1.3.0 is not yet released for CDH 4.

Workaround: Install using parcels (where the unreleased version of Impala does not appear), or select a different version of Impala when installing with packages.

When updating dynamic resource pools, Cloudera Manager updates roles but may fail to update role information displayed in the UI

When updating dynamic resource pools, Cloudera Manager automatically refreshes the affected roles, but they sometimes get marked incorrectly as running with outdated configurations and requiring a refresh.

Workaround: Invoke the Refresh Cluster command from the cluster actions drop-down menu.

User should be prompted to add the AMON role when adding MapReduce to a CDH 5 cluster

When the MapReduce service is added to a CDH 5 cluster, the user is not asked to add the AMON role. Then, an error displays when the user tries to view MapReduce activities.

Workaround: Manually add the AMON role after adding the MapReduce service.

Enterprise license expiration alert not displayed until Cloudera Manager Server is restarted

When an enterprise license expires, the expiration notification banner is not displayed until the Cloudera Manager Server has been restarted (although the expired enterprise features stop working immediately upon license expiration, as expected).

Workaround: None.

Cluster installation with CDH 4.1 and Impala fails

In Cloudera Manager 5.0, installing a new cluster through the wizard with CDH 4.1 and Impala fails with the following error message, "dfs.client.use.legacy.blockreader.local is not enabled."

Workaround: Perform one of the following:

  1. Use CDH 4.2 or higher, or
  2. Install all desired services except Impala in your initial cluster setup. From the home page, use the drop-down menu near the cluster name and select Configure CDH Version. Confirm the version, then add Impala.

HDFS replication does not work from CDH 5 to CDH 4 with different realms

HDFS replication does not work from CDH 5 to CDH 4 with different realms. This is because authentication fails for services in a non-default realm via the WebHdfs API due to a JDK bug. This has been fixed in JDK6-u34 (b03)) and in JDK7.

Workaround: Use JDK 7 or upgrade JDK6 to at least version u34.

Upgrade from Cloudera Manager 5.0.0 beta 1 or beta 2 to Cloudera Manager 5.0.0 requires assistance from Cloudera Support

Contact Cloudera Support before upgrading from Cloudera Manager 5.0.0 beta 1 or beta 2 to Cloudera Manager 5.0.0.

Workaround: Contact Cloudera Support.

Failure of HDFS Replication between clusters with YARN

HDFS replication between clusters in different Kerberos realms fails when using YARN if the target cluster is CDH 5.

Workaround: Use MapReduce (MRv1) instead of YARN.

Empty box appears over the list of results after adding a tag to a file

When tags are added to an entity, in some cases a white box remains after pressing Enter.

Workaround: Refresh the page to remove the artifact.

Upgrade of secure cluster requires installation of JCE policy files

When upgrading a secure cluster via Cloudera Manager, the upgrade initially fails due to the JDK not having Java Cryptography Extension (JCE) unlimited strength policy files. This is because Cloudera Manager installs a copy of the Java 7 JDK during the upgrade, which does not include the unlimited strength policy files. To ensure that unlimited strength functionality continues to work, install the unlimited strength JCE policy files immediately after completing the Cloudera Manager Upgrade Wizard and before taking any other actions in Cloudera Manager.

Workaround: Install the unlimited strength JCE policy files immediately after completing the Cloudera Manager Upgrade Wizard and before taking any other action in Cloudera Manager.

The Details page for MapReduce jobs displays the wrong id for YARN-based replications

The Details link for MapReduce jobs is wrong for YARN-based replications.

Workaround: Find the job id in the link and then go to the YARN Applications page and look for the job there.

The Spark Upload Jar command fails in a secure cluster

The Spark Upload Jar command fails in a secure cluster.

Workaround: To run Spark on YARN, manually upload the Spark assembly jar to HDFS /user/spark/share/lib. The Spark assembly jar is located on the local filesystem, typically in /usr/lib/spark/assembly/lib or /opt/cloudera/parcels/CDH/lib/spark/assembly/lib.

Configurations for decommissioned roles not migrated from MapReduce to YARN

When the Import MapReduce Configuration wizard is used to import MapReduce configurations to YARN, decommissioned roles in the MapReduce service do not cause the corresponding imported roles to be marked as decommissioned in YARN.

Workaround: Delete or decommission the roles in YARN after running the import.

The HDFS command Roll Edits does not work in the UI when HDFS is federated

The HDFS command Roll Edits does not work in the Cloudera Manager UI when HDFS is federated because the command doesn't know which nameservice to use.

Workaround: Use the API, not the Cloudera Manager UI, to execute the Roll Edits command.

Cloudera Manager reports a confusing version number if you have oozie-client, but not oozie installed on a CDH 4.4 node

In CDH versions before 4.4, the metadata identifying Oozie was placed in the client, rather than the server package. Consequently, if the client package is not installed, but the server is, Cloudera Manager will report Oozie has been present but as coming from CDH 3 instead of CDH 4.

Workaround: Either install the oozie-client package, or upgrade to at least CDH 4.4. Parcel based installations are unaffected.

The Sqoop Upgrade command in Cloudera Manager may report success even when the upgrade fails

Workaround: Do one of the following:

    1. Click the Sqoop service and then the Instances tab.
    2. Click the Sqoop server role then the Commands tab.
    3. Click the stdout link and scan for the Sqoop Upgrade command.
  • In the All Recent Commands page, select the stdout link for latest Sqoop Upgrade command.
Verify that the upgrade did not fail.

Cloudera Manager doesn't work with CDH 5.0.0 Beta 1

When you upgrade from Cloudera Manager 5.0.0 Beta 1 with CDH 5.0.0 Beta 1 to Cloudera Manager 5.0.0 Beta 2, Cloudera Manager won't work with CDH 5.0.0 Beta 1 and there's no notification of that fact.

Workaround: None. Do a new installation of CDH 5.0.0 Beta 2.

On CDH 4.1 secure clusters managed by Cloudera Manager 4.8.1 and higher, the Impala Catalog server needs advanced configuration snippet update

Impala queries fail on CDH 4.1 when Hive "Bypass Hive Metastore Server" option is selected.

Workaround: Add the following to Impala catalog server advanced configuration snippet for hive-site.xml, replacing Hive_Metastore_Server_Host with the host name of your Hive Metastore Server:


Rolling Upgrade to CDH 5 is not supported.

Rolling upgrade between CDH 4 and CDH 5 is not supported. Incompatibilities between major versions means rolling restarts are not possible. In addition, rolling upgrade will not be supported from CDH 5.0.0 Beta 1 to any later releases, and may not be supported between any future beta versions of CDH 5 and the General Availability release of CDH 5.

Workaround: None.

Error reading .zip file created with the Collect Diagnostic Data command.

After collecting Diagnostic Data and using the Download Diagnostic Data button to download the created zip file to the local system, the zip file cannot be opened using the FireFox browser on a Macintosh. This is because the zip file is created as a Zip64 file, and the unzip utility included with Macs does not support Zip64. The zip utility must be version 6.0 or later. You can determine the zip version with unzip -v.

Workaround: Update the unzip utility to a version that supports Zip64.

Enabling wildcarding in a secure environment causes NameNode to fail to start.

In a secure cluster, you cannot use a wildcard for the NameNode's RPC or HTTP bind address, or the NameNode will fail to start. For example,dfs.namenode.http-address must be a real, routable address and port, not In Cloudera Manager, the "Bind NameNode to Wildcard Address" property must not be enabled. This should affect you only if you are running a secure cluster and your NameNode needs to bind to multiple local addresses.

Bug: HDFS-4448

Severity: Medium

Workaround: Disable the "Bind NameNode to Wildcard Address" property found under the Configuration tab for the NameNode role group.

After JobTracker failover, complete jobs from the previous active JobTracker are not visible.

When a JobTracker failover occurs and a new JobTracker becomes active, the new JobTracker UI does not show the completed jobs from the previously active JobTracker (that is now the standby JobTracker). For these jobs the "Job Details" link does not work.

Severity: Med

Workaround: None.

After JobTracker failover, information about rerun jobs is not updated in Activity Monitor.

When a JobTracker failover occurs while there are running jobs, jobs are restarted by the new active JobTracker by default. For the restarted jobs the Activity Monitor will not update the following: 1) The start time of the restarted job will remain the start time of the original job. 2) Any Map or Reduce task that had finished before the failure happened will not be updated with information about the corresponding task that was rerun by the new active JobTracker.

Severity: Med

Workaround: None.

Installing on AWS, you must use private EC2 hostnames.

When installing on an AWS instance, and adding hosts using their public names, the installation will fail when the hosts fail to heartbeat.

Severity: Med


Use the Back button in the wizard to return to the original screen, where it prompts for a license.

Rerun the wizard, but choose "Use existing hosts" instead of searching for hosts. Now those hosts show up with their internal EC2 names.

Continue through the wizard and the installation should succeed.

After removing and then re-adding a service, the alternatives settings are incorrect.

After deleting a service, the alternatives settings are not cleaned up. If you then re-add the service, it will be given a new instance name, and a new set of configurations settings are added. However, because both the new and old (deleted) instances have the same alternatives priority, the original one will be used rather than the newer one.

Severity: Med

Workaround: The simplest way to fix this is:

  1. Go to the Configuration tab for the new service instance in Cloudera Manager
  2. Search for "alternatives".
  3. Raise the priority value and save the setting.
  4. Redeploy the client configuration.

If HDFS uses Quorum-based Storage without HA enabled, the SecondaryNameNode cannot checkpoint.

If HDFS is set up in non-HA mode, but with Quorum-based storage configured, the dfs.namenode.edits.dir is automatically configured to the Quorum-based Storage URI. However, the SecondaryNameNode cannot currently read the edits from a Quorum-based Storage URI, and will be unable to do a checkpoint.

Severity: Medium

Workaround: Add to the NameNode's advanced configuration snippet the dfs.namenode.edits.dir property with both the value of the Quorum-based Storage URI as well as a local directory, and restart the NameNode. For example,

<property> <name>dfs.namenode.edits.dir</name>

Changing the rack configuration may temporarily cause mis-replicated blocks to be reported.

A rack re-configuration will cause HDFS to report mis-replicated blocks until HDFS rebalances the system, which may take some time. This is a normal side-effect of changing the configuration.

Severity: Low

Workaround: None

Cannot use '/' as a mount point with a Federated HDFS Nameservice.

A Federated HDFS Service doesn't support nested mount points, so it is impossible to mount anything at '/'. Because of this issue, the root directory will always be read-only, and any client application that requires a writeable root directory will fail.

Severity: Low


  1. In the CDH 4 HDFS Service > Configuration tab of the Cloudera Manager Admin Console, search for "nameservice".
  2. In the Mountpoints field, change the mount point from "/" to a list of mount points that are in the namespace that the Nameservice will manage. (You can enter this as a comma-separated list - for example, "/hbase, /tmp, /user" or by clicking the plus icon to add each mount point in its own field.) You can determine the list of mount points by running the command hadoop fs -ls / from the CLI on the NameNode host.

Historical disk usage reports do not work with federated HDFS.

Severity: Low

Workaround: None.

(CDH 4 only) Activity monitoring does not work on YARN activities.

Activity monitoring is not supported for YARN in CDH 4.

Severity: Low

Workaround: None

HDFS monitoring configuration applies to all Nameservices

The monitoring configurations at the HDFS level apply to all Nameservices. So, if there are two federated Nameservices, it's not possible to disable a check on one but not the other. Likewise, it's not possible to have different thresholds for the two Nameservices.

Severity: Low

Workaround: None

Supported and Unsupported Replication Scenarios and Limitations

See Data Replication

Restoring snapshot of a file to an empty directory does not overwrite the directory

Restoring the snapshot of an HDFS file to an HDFS path that is an empty HDFS directory (using the Restore As action) will result in the restored file present inside the HDFS directory instead of overwriting the empty HDFS directory.

Workaround: None.

HDFS Snapshot appears to fail if policy specifies duplicate directories.

In an HDFS snapshot policy, if a directory is specified more than once, the snapshot appears to fail with an error message on the Snapshot page. However, in the HDFS Browser, the snapshot is shown as having been created successfully.

Severity: Low

Workaround: Remove the duplicate directory specification from the policy.

Hive replication fails if "Force Overwrite" is not set.

The Force Overwrite option, if checked, forces overwriting data in the target metastore if there are incompatible changes detected. For example, if the target metastore was modified and a new partition was added to a table, this option would force deletion of that partition, overwriting the table with the version found on the source. If the Force Overwrite option is not set, recurring replications may fail.

Severity: Med

Workaround: Set the Force Overwrite option.

During HDFS replication, tasks may fail due to DataNode timeouts.

In CDH 4.2, during an HDFS replication job (using Cloudera Manager's Backup and Data Recovery product) individual tasks in the Replication job may fail due to DataNode timeouts. If enough of these timeouts occur, the replication task may slow down, and the entire replication job could time out and fail.

Severity: Medium

Workaround: None.




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