Hive external table replication policies

Hive external table replication policies enable you to copy (replicate) your Hive metastore and data from one cluster to another and synchronize the Hive metastore and data set on the 'destination' cluster with the source, based on a specified replication policy. You can also use CDP Private Cloud Base Replication Manager to replicate Hive/Impala data to and from S3 or ADLS, however you cannot replicate data from one S3 or ADLS instance to another using Replication Manager.

The destination cluster must be managed by the Cloudera Manager Server where the replication is being set up, and the source cluster can be managed by that same server or by a peer Cloudera Manager Server.

Configuration notes
  • If the hadoop.proxyuser.hive.groups configuration has been changed to restrict access to the Hive Metastore Server to certain users or groups, the hdfs group or a group containing the hdfs user must also be included in the list of groups specified for Hive/Impala replication to work. This configuration can be specified either on the Hive service as an override, or in the core-site HDFS configuration. This applies to configuration settings on both the source and destination clusters.
  • If you configured on the target cluster for the directory where HDFS data is copied during Hive/Impala replication, the permissions that were copied during replication, are overwritten by the HDFS ACL synchronization and are not preserved
Hive external table replication policies do not support managed to managed table replication. When you replicate from a CDH cluster to a CDP Private Cloud Base cluster, Replication Manager converts managed tables to external tables. Therefore, to replicate managed tables (ACID) and external tables in a database successfully, you must perform the following steps in the order shown below:
  1. Create Hive ACID table replication policy for the database to replicate the managed data.
  2. After the replication completes, create the Hive external table replication policy to replicate the external tables in the database.
To replicate Hive/Impala data to and from S3 or ADLS, you must have the appropriate credentials to access the S3 or ADLS account. Additionally, you must create buckets in S3 or data lake store in ADLS. Replication Manager backs up file metadata, including extended attributes and ACLs when you replicate data to cloud storage. Replication Manager supports the following replication scenarios:
  • Replicate to and from Amazon S3 from CDH 5.14+ and Cloudera Manager version 5.13+.

    Replication Manager does not support S3 as a source or destination when S3 is configured to use SSE-KMS.

  • Replicate to and from Microsoft ADLS Gen1 from CDH 5.13+ and Cloudera Manager 5.15, 5.16, 6.1+.
  • Replicate to Microsoft ADLS Gen2 (ABFS) from CDH 5.13+ and Cloudera Manager 6.1+.