Cloudera Docs

Migrating HBase data from CDH/HDP to COD CDP Public Cloud

When you are migrating from CDH or HDP to COD CDP Public Cloud, you have to set up the Cloudera Replication Plugin and then use a snapshot to migrate your data to COD CDP Public Cloud. Once your data is migrated, optionally you can use the HashTable/CldrSyncTable tool to verify the migration.

Ensure you have understood and performed all the necessary data migration preparation tasks listed in HBase migration prerequisites.

  1. Provide the Cloudera Replication Plugin by configuring HBase Client Environment Advanced Configuration Snippet (Safety Valve) for hbase-env.sh for Gateway and HBase Service Environment Advanced Configuration Snippet (Safety Valve) for RegionServers and Masters on the source cluster.
    1. In Cloudera Manager, navigate to HBase > Configuration.
    2. Find the HBase Client Environment Advanced Configuration Snippet (Safety Valve) for hbase-env-sh property and add the following configuration to provide the Cloudera Replication Plugin path for the Gateway:
      HBASE_CLASSPATH=$HBASE_CLASSPATH:/opt/cloudera/parcels/cloudera-opdb-replication-[***REPLICATION PLUGIN VERSION***]-cdh[***CDH VERSION***]-/lib/*
      For example:
      HBASE_CLASSPATH=$HBASE_CLASSPATH:/opt/cloudera/parcels/cloudera-opdb-replication-1.0-cdh5.14.4-/lib/*
    3. Find the HBase Service Environment Advanced Configuration Snippet (Safety Valve) property and add the same configuration to provide the Cloudera Replication Plugin path for RegionServers and Masters:
      HBASE_CLASSPATH=$HBASE_CLASSPATH:/opt/cloudera/parcels/cloudera-opdb-replication-[***REPLICATION PLUGIN VERSION***]-cdh[***CDH VERSION***]-/lib/*
      For example:
      HBASE_CLASSPATH=$HBASE_CLASSPATH:/opt/cloudera/parcels/cloudera-opdb-replication-1.0-cdh5.14.4-/lib/*

      For more information on CDH parcels, see Migrating HBase tables.

    1. In Ambari, navigate to CONFIGS > ADVANCED > Advanced hbase-env > hbase-env template.
    2. Find the following line:
      export HBASE_CLASSPATH=${HBASE_CLASSPATH}
    3. Modify the line to include the following configuration:
      export HBASE_CLASSPATH=${HBASE_CLASSPATH}:/usr/hdp/cloudera-opdb-replication-[***REPLICATION PLUGIN VERSION***]-hdp[***version***]-SNAPSHOT/lib/*
      For example:
      export HBASE_CLASSPATH=${HBASE_CLASSPATH}:/usr/hdp/cloudera-opdb-replication-1.0-hdp-2.6.5-SNAPSHOT/lib/*
  2. Generate and distribute credentials.
    1. Create a machine user with the name hbase-replication (or any one of your choice) in User Management Service (UMS) on the CDP Management Console.
    2. Set your workload password.
    3. Add this machine user as an Environment User using Manage Access in the destination CDP environment.
    4. Perform FreeIPA synchronization for the destination environments.
    5. Verify credentials using the kinit srv_$YOUR_REP_USER (for example, if the specified user was hbase-replication, this would be srv_hbase-replication) command on any node.
    6. In the destination cluster, run the following command to generate the keystore: 
      hbase 
com.cloudera.hbase.security.token.CldrReplicationSecurityTool -sharedkey cloudera -password [***PASSWORD***] -keystore localjceks://file/tmp/credentials.jceks
    7. Obtain hdfs user kerberos credentials on the destination cluster.

      Ensure that you have root access to execute the following command.

      kinit -kt /var/run/cloudera-scm-agent/process/`ls -1 /var/run/cloudera-scm-agent/process/ | grep -i "namenode\|datanode" | sort -n | tail -1`/hdfs.keytab hdfs/$(hostname -f)
    8. Add the generated jceks file to related hdfs folder in the destination cluster: 
      hdfs dfs -mkdir /hbase-replication
hdfs dfs -put /tmp/credentials.jceks /hbase-replication
hdfs dfs -chown -R hbase:hbase /hbase-replication
    9. Copy the generated jceks file to any host of the source cluster.
    10. Add the copied jceks file to related hdfs folder in the source cluster (if source cluster is secured, you need hdfs kerberos credentials for destination cluster): 
      hdfs dfs -mkdir /hbase-replication
hdfs dfs -put /tmp/credentials.jceks /hbase-replication
hdfs dfs -chown -R hbase:hbase /hbase-replication
  3. Set the hbase.security.replication.credential.provider.path property on the destination cluster using the HBase Service Advanced Configuration Snippet (Safety Valve) for hbase-site.xml property.
    For example, if the path to the jceks file is hdfs://ns1/hbase-replication/credentials.jceks, set the following configuration:
    <property>
<name>hbase.security.replication.credential.provider.path</name>
<value>cdprepjceks://hdfs@[***NAMESERVICE***]/hbase-replication/credentials.jceks</value>
</property>
  4. In the source cluster, enable replication for each table that you want to replicate:
    This can be done b setting the REPLICATION_SCOPE on the desired column families for that HBase table in the hbase shell.
    $ hbase shell
alter 'my-table', {NAME=>'my-family', REPLICATION_SCOPE => '1'}
    If you do not know what column families exist in your HBase table, use the describe command:
    $ hbase shell
describe ‘my-table’
  5. Set up the cloud services provider credentials for the source cluster using the core-site.xml HDFS configuration file.
    1. Find the core-site.xml HDFS configuration file:
      • Cloudera Manager: Navigate to HDFS > Configuration and find the Cluster-wide Advanced Configuration Snipper (Safety Valve) for core-site.xml property.
      • Ambari: Navigate to HDFS > CONFIGS > ADVANCED and find the custom core-site template.
    2. Add the following configuration:
      Configure the following properties on the source cluster with the AWS keys and write permission to the bucket:
      • fs.s3a.access.key
      • fs.s3a.secret.key
      • fs.s3a.endpoint

      For example, fs.s3a.endpoint="s3.eu-central-1.amazonaws.com"

      Configure your storage account access key by setting the fs.azure.account.key.[***ACCOUNT NAME***].blob.core.windows.net property to the access key:
      <property>  <name>fs.azure.account.key.[***ACCOUNT NAME***].blob.core.windows.net</name>
<value>[***ACCOUNT NAME***]-ACCESS-KEY</value>
</property>
      Access key can be obtained from the Access keys in your storage account settings.
  6. Restart the RegionServers and add the client configurations on the source cluster:
    • Cloudera Manager: Click Restart stale services.
    • Ambari: Click Restart all required.
  7. Use the ReplicationSetupTool tool on the source cluster to define the replication peer.
    Run this command as the hbase user. Additionally, use the same keystore path that you provided in Step 3. 

    sudo -u hbase hbase org.apache.hadoop.hbase.client.replication.ReplicationSetupTool -clusterKey "zk-host-1,zk-host-2,zk-host-3:2181:/hbase" -endpointImpl "org.apache.hadoop.hbase.replication.regionserver.CldrHBaseInterClusterReplicationEndpoint" -peerId 1 -credentialPath "cdprepjceks://hdfs@[***NAMESERVICE***]/hbase-replication/credentials.jceks" -replicationUser srv_hbase-replication

    This example uses sudo. However, you can use kinit if it is appropriate for your source cluster setup.

    The clusterKey parameter reflects the destination cluster's zookeeper quorum address. Here, zk-host-1, zk-host-2, zk-host-3 represent the destination cluster Zookeeper hostnames.

    NAMESERVICE is the source cluster nameservice for HA enabled cluster. It can also be the hostname of an active NameNode for a non-HA cluster.

  8. Disable the replication peer in the hbase shell.
    Disabling the peer before taking the snapshot ensures that incremental data written to your table is not lost while copying the HBase snapshot to COD.
    $./bin/hbase shell
hbase> disable_peer '1'
  9. Take a snapshot on the source cluster.
    1. In Cloudera Manager on the source cluster, select the HBase service.
    2. Click Table Browser.
    3. Select a table.
    4. Click Take Snapshot.
    5. Specify the name of the snapshot and click Take Snapshot.
    1. You can take the snapshot through the hbase shell:
      $ hbase shell
hbase> snapshot 'myTable', 'myTableSnapshot-122112'
  10. Export the snapshot to the destination cluster using the ExportSnapshot tool.
    You must run the ExportSnapshot command as the hbase user or as the user that owns the files. The ExportSnapshot tool executes a MapReduce job similar to distcp to copy files to the other cluster. The tool works at the file-system level, so the HBase cluster can be offline, but ensure that the HDFS cluster is online.
    1. Navigate to Cloudera Management Console > CDP Operational Database > your Database or Environment.
    2. Copy the Cloud Storage Location.
      • In the case of AWS, this is a s3a path: s3a://bucket/path/hbase
      • In the case of Azure blob storage (ABFS), this is an abfs path: abfs://<storagename>/datalake/<datahub_name>/hbase
    3. Run the following command in the hbase shell on the source cluster to export a snapshot from the source cluster to the destination cluster: 
      hbase org.apache.hadoop.hbase.snapshot.ExportSnapshot -snapshot [***SNAPSHOT NAME***] -copy-to [***DESTINATION***] -mappers 16

      Replace [***DESTINATION***] with the s3a or abfs path obtained in step b.

    It may be necessary to increase the value of the hbase.master.hfilecleaner.ttl property in the source cluster to work around known issues in HBase file cleaning due to known issues in these legacy products.
  11. Verify that the snapshot exist in the COD database using the following command: 
    $ hbase shell
hbase> list_snapshots
  12. Restore the snapshot into an HBase table using the following command: 
    $./bin/hbase shell
hbase> restore_snapshot [***SNAPSHOT_NAME***]
  13. Enable the peer on the source cluster to begin replicating data: 
    $./bin/hbase shell
hbase> enable_peer '1'
  14. Optional: Use the HashTable/CldrSyncTable tool to ensure that data is synchronized between your source and destination clusters.
    1. Run HashTable on the source cluster: 
      hbase org.apache.hadoop.hbase.mapreduce.HashTable [***TABLE NAME***] [***HASH OUTPUT PATH***]
hdfs dfs -ls -R [***HASH OUTPUT PATH***]
      Hashed indexes are generated on the source cluster.
    2. Run CldrSyncTable with the -cldr.cross.domain option on the source cluster: 
      hbase org.apache.hadoop.hbase.mapreduce.CldrSyncTable --cldr.cross.domain --targetzkcluster=[***TARGET ZOOKEEPER QUORUM***]:[***TARGET ZOOKEEPER PORT***]:[***TARGET ZOOKEEPER ROOT FOR HBASE***]
[***HASH OUTPUT PATH***] [***SOURCE TABLE NAME***] [***TARGET TABLE NAME ON THE TARGET CLUSTER***]
      Hash indexes are generated on the destination cluster and compared to the hash indexes generated on the source cluster. If the hash indexes are not identical, synchronization is run for that section of rows.