Compatibility Considerations for Virtual Private Clusters

CDH Version Compatibility

The CDH version of the Compute cluster must match the major.minor version of the Base cluster. Support for additional combinations of Compute and Base cluster versions may be added at a later time. The following CDH versions are supported for creating Virtual Private Clusters:
  • CDH 5.15
  • CDH 5.16
  • CDH 6.0
  • CDH 6.1
  • CDH 6.2

CDH Components

  • Kafka – Not supported on Compute clusters
  • SOLR – Not supported on Compute clusters
  • Kudu – Not supported on Compute clusters.

    Storage locations on HiveMetastore using Kudu are not available to Impala on Compute clusters.

  • HDFS
    • A “local” HDFS service is required on Compute clusters as temporary, persistent space; the intent is to use this for Hive temporary queries and is also recommended for multi-stage Spark ETL jobs.
    • Cloudera recommends a minimum storage of 1TB per host, configured as the HDFS DataNode storage directory.
    • The Base cluster must have an HDFS service.
    • Isilon is not supported on the Base cluster.
    • S3 and ADLS connectors are supported only on the Base cluster; Compute clusters will use the supplied S3 or ADLS credentials from their associated Base cluster
    • The HDFS service on the Base cluster must be configured for high availability.
    • Cloudera highly recommends enabling high availability for the HDFS service on the Compute cluster, but it is not required.

    • The Base and compute nameservice names must be distinct.

    • The following configurations for the local HDFS service on a compute cluster must match the configurations on the Base cluster. This enables services on the Compute cluster to correctly access services on the Base cluster:
      • Hadoop RPC protection

      • Data Transfer protection

      • Enable Data Transfer Encryption

      • Kerberos Configurations
      • TLS/SSL Configuration (only when the cluster is not using Auto-TLS). See Security.
    • Do not override the nameservice configuration in the Compute cluster by using Advanced Configuration Snippets.
    • The HDFS path to compute cluster home directories use the following structure: /mc/<cluster_id>/fs/user
      You can find the <cluster_id> by clicking the cluster name in the Cloudera Manager Admin Console. The URL displayed by your browser includes the cluster id. For example, in the URL below, the cluster ID is 1.
      http://myco-1.prod.com:7180/cmf/clusters/1/status
  • Backup and Disaster Recovery (BDR) – not supported when the source cluster is a Compute cluster and the target cluster is running a version of Cloudera Manager lower than 6.2.
  • YARN and MapReduce
    • If both MapReduce (MR1, Deprecated in CM6) and YARN (MR2) are available on the Base cluster, dependent services in the Compute cluster such as Hive Execution Service will use MR1 because of the way service dependencies are handled in Cloudera Manager. To use YARN, you can update the configuration to make these Compute cluster services depend on YARN (MR2) before using YARN in your applications.
  • Impala
    • Ingesting new data or metadata into the Base cluster affecting the Hive Metastore requires running the INVALIDATE METADATA or REFRESH METADATA statement on each Compute cluster with Impala installed, prior to use.
    • Consistency in Impala is guaranteed by table-level locks in the Catalog Service (catalogd). With multiple Compute clusters, accessing the same table or data from multiple clusters through multiple catalogds can lead to problems. For example, query can fail when removing files, or incorrect data gets into metadata when a refresh running on one cluster picks up half the data that's being ingested from another cluster.

      To avoid consistency problems, your Impala clusters should operate on mutually exclusive sets of tables and data.

  • Hue
    • Only one Hue service instance is supported on a Compute cluster.
    • The Hue service on Compute clusters will not share user-specific query history with the Hue service on other Compute clusters or Hue services on the Base cluster
    • Hue examples may not install correctly due to differing permissions for creating tables and inserting data. You can work around this problem by deleting the sample tables and then re-adding them.
    • If you add Hue to a Compute cluster after the cluster has already been created, you will need to manually configure any dependencies on other services (such as Hive, Hive Execution Service, and Impala) in the Compute cluster.
  • Hive Execution Service

    The newly introduced “Hive execution service” is only supported on Compute clusters, and is not supported on Base or Regular clusters.

    To enable Hue to run Hive queries on a Compute cluster, you must install the Hive Execution Service on the Compute cluster. See rg_cm_620_known_issues.html#concept_rxr_2cy_2hb.

Compute Cluster Services

Only the following services can be installed on Compute clusters:
  • Hive Execution Service (This service supplies the HiveServer2 role only.)
  • Hue
  • Impala
  • Spark 2
  • Oozie (only when Hue is available, and is a requirement for Hue)
  • YARN
  • HDFS (required)

Cloudera Navigator Support

Navigator audit, lineage and metadata, and Navigator KMS are not supported on Compute clusters.

See Cloudera Navigator support for Virtual Private Clusters.

Cloudera Manager Permissions

Cluster administrators who are authorized to only see Base or Compute clusters can only see and administer these clusters, but cannot create, delete, or manage Data Contexts. Data context creation and deletion is only allowed with the Full Administrator use role or for unrestricted Cluster Administrators.

Security

  • KMS
    • Base cluster:
      • Hadoop KMS is not supported.
      • KeyTrustee KMS is supported on Base cluster.
    • Compute cluster: Any type of KMS is not supported.

  • Authentication/User directory
    • Users should be identically configured on hosts on compute and Base clusters, as if the nodes are part of the same cluster. This includes Linux local users, LDAP, Active Directory, or other third-party user directory integrations.
  • Kerberos
    • If a Base cluster has Kerberos installed, then the Compute and Base clusters must both use Kerberos in the same Kerberos realm. The Cloudera Manager Admin Console helps facilitate this configuration in the cluster creation process to ensure compatible Kerberos configuration.
  • TLS
    • If the Base cluster has TLS configured for cluster services, Compute cluster services must also have TLS configured for services that access those Base cluster services.
    • Cloudera strongly recommends enabling Auto-TLS to ensure that services on Base and Compute clusters uniformly use TLS for communication.
    • If you have configured TLS, but are not using Auto-TLS, note the following:
      • You must create an identical configuration on the Compute cluster hosts before you add them to a Compute cluster using Cloudera Manager. Copy all files located in the directories specified by the following configuration properties, from the Base clusters to the Compute cluster hosts:
        • hadoop.security.group.mapping.ldap.ssl.keystore
        • ssl.server.keystore.location
        • ssl.client.truststore.location
      • Cloudera Manager will copy the following configurations to the compute cluster when you create the Compute cluster.
        • hadoop.security.group.mapping.ldap.use.ssl
        • hadoop.security.group.mapping.ldap.ssl.keystore
        • hadoop.security.group.mapping.ldap.ssl.keystore.password
        • hadoop.ssl.enabled
        • ssl.server.keystore.location
        • ssl.server.keystore.password
        • ssl.server.keystore.keypassword
        • ssl.client.truststore.location
        • ssl.client.truststore.password

Storage Requirements for Hosts in Compute clusters

If Impala is running on the Compute cluster, the Compute cluster hosts will require attached storage, with a minimum of 1TB capacity. This storage is used for Impala scratch space and for DFS local storage in hosts that have an HDFS DataNode role assigned.

Networking

Workloads running on Compute clusters will communicate heavily with hosts on the Base cluster; Customers should have network monitoring in place for networking hardware (such as switches including top-of-rack, spine/leaf routers and so on) to track and adjust bandwidth between racks hosting hosts utilized in Compute and Base clusters.

You can also use the Cloudera Manager Network Performance Inspector to evaluate your network.

For more information on how to set up networking, see Networking Considerations for Virtual Private Clusters.

Altus Director

Altus Director does not support running Compute clusters and cannot be used to create Compute clusters.

Cloudera Data Science Workbench (CDSW)

CDSW is not supported for Compute clusters.