Accessing the remote CDP cluster HBase data from another CDP cluster using Spark in Kerberized environment.

This article will describe the steps to access the remote CDP cluster HBase data from another CDP cluster using Spark in Kerberized environment.

Assume we have two clusters say 'Cluster_A' and 'Cluster_B'. 'Cluster_A' is having the HBase data. 'Cluster_B' is having Spark. Now, we are trying to access the HBase data available in 'Cluster_A' using Spark from 'Cluster_B'.

Prerequisites:

Both clusters 'Cluster_A' and 'Cluster_B' with keytabs need to have the same REALM.

Follow these steps: 

1. Login to 'Cluster_A' edge node
2. Obtain the Kerberos ticket using kinit:
   

   kinit -kt <key_tab_file> <principal_name>​

3. Login to the Hbase shell and create the 'person' table:
   

   ranga]# hbase shell
   
   hbase(main):001:0> list
   TABLE
   0 row(s)
   
   hbase(main):013:0> create 'person', 'p'
   Created table person
   Took 8.2307 seconds
   => Hbase::Table - person
   
   hbase(main):014:0> put 'person',1,'p:id','1'
   Took 0.0173 seconds
   hbase(main):015:0> put 'person',1,'p:name','Ranga Reddy'
   Took 0.0045 seconds
   hbase(main):016:0> put 'person',1,'p:email','ranga@gmail.com'
   Took 0.0043 seconds
   hbase(main):017:0> put 'person',1,'p:age','25'
   Took 0.0049 seconds
   hbase(main):018:0> scan 'person'
   ROW                                                              COLUMN+CELL
    1                                                               column=p:age, timestamp=1616425683759, value=25
    1                                                               column=p:email, timestamp=1616425681754, value=ranga@gmail.com
    1                                                               column=p:id, timestamp=1616425681717, value=1
    1                                                               column=p:name, timestamp=1616425681736, value=Ranga Reddy
   
   hbase(main):018:0> exit

4. Copy the hbase-site.xml from 'Cluster_A' to 'Cluster_B':
   

   scp /etc/hbase/conf/hbase-site.xml root@cluster_b_ipaddress:/tmp​

5. Login to 'Cluster_B' edge node
6. Obtain the Kerberos ticket using kinit:
   

   kinit -kt <key_tab_file> <principal_name>

7. Place the above-copied hbase-site.xml (in Step 4) into some temporary directory. Example: /tmp/hbase/conf
   

   mkdir -p /tmp/hbase/conf
   cp /tmp/hbase-site.xml /tmp/hbase/conf

8. Launch the Spark shell by providing HBase Spark connector packages and HBase configuration (/tmp/hbase/conf) directory:
   

   spark-shell \
   --master yarn \
   --conf spark.driver.extraClassPath=/tmp/hbase/conf \
   --conf spark.executor.extraClassPath=/tmp/hbase/conf \
   --jars /opt/cloudera/parcels/CDH/lib/hbase_connectors/lib/hbase-spark-1.0.0*.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase_connectors/lib/hbase-spark-protocol-shaded-*.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-client.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-common.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-server.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-mapreduce.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-shaded-miscellaneous.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-shaded-protobuf.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-protocol-shaded.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-protocol.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-protocol-shaded.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-shaded-netty.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-zookeeper.jar,\
   /opt/cloudera/parcels/CDH/jars/htrace-core-3.1.0-incubating.jar,\
   /opt/cloudera/parcels/CDH/lib/hbase/hbase-annotations.jar

9. Run the following code after launching the spark-shell:
   

   val df = spark.read.format("org.apache.hadoop.hbase.spark").option("hbase.columns.mapping", "id STRING :key, name STRING :p:name, email STRING p:email, age STRING p:age").option("hbase.table", "person").option("hbase.spark.use.hbasecontext", false).load()
   df.show(truncate=false)

   The output of the above command:
   

   scala> df.show(truncate=false)
   +---+----+---------------+---+
   |age|name|email |id |
   +---+----+---------------+---+
   |25 |1 |ranga@gmail.com| |
   +---+----+---------------+---+