Prerequisites :
>>Enable hive interactive server in hive

>>Get following details from hive for spark

spark.hadoop.hive.llap.daemon.service.hosts @llap0
spark.sql.hive.hiveserver2.jdbc.url  jdbc:hive2://c420-node2.squadron-labs.com:2181,c420-node3.squadron-labs.com:2181,c420-node4.squadron-labs.com:2181/;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=hiveserver2-interactive
spark.datasource.hive.warehouse.load.staging.dir /tmp
spark.datasource.hive.warehouse.metastoreUri thrift://c420-node3.squadron-labs.com:9083
spark.security.credentials.hiveserver2.enabled false



Basic testing :

1) Create a table employee in hive and load some data
        eg:
        Create table
        ----------------

```CREATE TABLE IF NOT EXISTS employee ( eid int, name String, salary String, destination String)
COMMENT 'Employee details'
ROW FORMAT DELIMITED
FIELDS TERMINATED BY ','
LINES TERMINATED BY '\n'
STORED AS TEXTFILE;
```
        Load data data.txt file into hdfs
        ---------------
```
1201,Gopal,45000,Technical manager
1202,Manisha,45000,Proof reader
1203,Masthanvali,40000,Technical writer
1204,Kiran,40000,Hr Admin
1205,Kranthi,30000,Op Admin
```

```LOAD DATA INPATH '/tmp/data.txt' OVERWRITE INTO TABLE employee;```

2) kinit to the spark user and run

spark-shell --master yarn --conf "spark.security.credentials.hiveserver2.enabled=false" --conf "spark.sql.hive.hiveserver2.jdbc.url=jdbc:hive2://c420-node2.squadron-labs.com:2181,c420-node3.squadron-labs.com:2181,c420-node4.squadron-labs.com:2181/;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=hiveserver2-interactive;principal=hive/_HOST@HWX.COM" --conf "spark.datasource.hive.warehouse.metastoreUri=thrift://c420-node3.squadron-labs.com:9083" --conf "spark.datasource.hive.warehouse.load.staging.dir=/tmp/" --conf "spark.hadoop.hive.llap.daemon.service.hosts=@llap0" --conf "spark.hadoop.hive.zookeeper.quorum=c420-node2.squadron-labs.com:2181,c420-node3.squadron-labs.com:2181,c420-node4.squadron-labs.com:2181" --jars /usr/hdp/current/hive_warehouse_connector/hive-warehouse-connector-assembly-1.0.0.3.0.1.0-187.jar

Note: spark.security.credentials.hiveserver2.enabled should be set to false for YARN client deploy mode, and true for YARN cluster deploy mode (by default). This configuration is required for a Kerberized cluster

3) run following code in scala shell to view the table data
import com.hortonworks.hwc.HiveWarehouseSession
val hive = HiveWarehouseSession.session(spark).build()
hive.execute("show tables").show
hive.executeQuery("select * from employee").show



4) To apply common properties by default, add following setting into ambari spark2 custom conf


spark.sql.hive.hiveserver2.jdbc.url=jdbc:hive2://c420-node2.squadron-labs.com:2181,c420-node3.squadron-labs.com:2181,c420-node4.squadron-labs.com:2181/;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=hiveserver2-interactive;principal=hive/_HOST@HWX.COM
spark.datasource.hive.warehouse.metastoreUri=thrift://c420-node3.squadron-labs.com:9083
spark.datasource.hive.warehouse.load.staging.dir=/tmp/
spark.hadoop.hive.llap.daemon.service.hosts=@llap0
spark.hadoop.hive.zookeeper.quorum=c420-node2.squadron-labs.com:2181,c420-node3.squadron-labs.com:2181,c420-node4.squadron-labs.com:2181


5) spark-shell --master yarn  --conf "spark.security.credentials.hiveserver2.enabled=false" --jars /usr/hdp/current/hive_warehouse_connector/hive-warehouse-connector-assembly-1.0.0.3.0.1.0-187.jar
Note: Common properties are read from spark default properties

6) run following code in scala shell to view the hive table data
```
import com.hortonworks.hwc.HiveWarehouseSession
val hive = HiveWarehouseSession.session(spark).build()
hive.execute("show tables").show
hive.executeQuery("select * from employee").show
```

7) To integrate HWC in Livy2

  a) add following property in Custom livy2-conf
livy.file.local-dir-whitelist=/usr/hdp/current/hive_warehouse_connector/
  b) Add hive-site.xml to /usr/hdp/current/spark2-client/conf on all cluster nodes.

  c) In livy2 interpreter  settings add following

livy.spark.hadoop.hive.llap.daemon.service.hosts	@llap0
livy.spark.security.credentials.hiveserver2.enabled	true
livy.spark.sql.hive.hiveserver2.jdbc.url	jdbc:hive2://c420-node2.squadron-labs.com:2181,c420-node3.squadron-labs.com:2181,c420-node4.squadron-labs.com:2181/;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=hiveserver2-interactive
livy.spark.sql.hive.hiveserver2.jdbc.url.principal	hive/_HOST@HWX.COM
livy.spark.yarn.security.credentials.hiveserver2.enabled	true
livy.spark.jars file:///usr/hdp/current/hive_warehouse_connector/hive-warehouse-connector-assembly-1.0.0.3.0.1.0-187.jar

  d) Restart livy2 interpreter

  e) in first paragraph add
  %livy2
import com.hortonworks.hwc.HiveWarehouseSession
val hive = HiveWarehouseSession.session(spark).build()

  f) in second paragraph add
   %livy2
hive.executeQuery("select * from employee").show