Enabling High Availability for Spark Thrift Server

With MEPs 5.0.4 or 6.3.0 and later, you can enable high availability for the Spark Thrift Server. Unlike a HiveServer2 high-availability configuration, Spark has no concept of active-active instances. However, after configuration, you can can use Beeline to connect to the Spark Thrift Server on each node.

To enable high availability, use the following steps:

Install Spark Thrift Server on all the cluster nodes where it is needed:

On Ubuntu

apt-get install mapr-spark-thriftserver

On Red Hat / CentOS

yum install mapr-spark-thriftserver

On SLES

zypper install mapr-spark-thriftserver

Add the following properties to the /opt/mapr/spark/spark-<spark_version>/conf/hive-site.xml file on all the nodes where the Spark Thrift Server is installed

<property>
<name>hive.zookeeper.quorum</name>
<value><zk_host1_>,<zk_host_2>,…,<zk_host_n></value>
</property>

<property>
<name>hive.zookeeper.client.port</name>
<value><zk_port></value>
</property>

<property>
<name>hive.server2.support.dynamic.service.discovery</name>
<value>true</value>
</property>

<property>
<name>hive.server2.zookeeper.namespace</name>
<value><zk_namespace></value>
</property>

For example:

<property>
<name>hive.zookeeper.quorum</name>
<value>node1.cluster.com,node2.cluster.com,node3.cluster.com</value>
</property>

<property>
<name>hive.zookeeper.client.port</name>
<value>5181</value>
</property>

<property>
<name>hive.server2.support.dynamic.service.discovery</name>
<value>true</value>
</property>

<property>
<name>hive.server2.zookeeper.namespace</name>
<value>ts2-ts2</value>
</property>

NOTE The values that you provide for the hive.server2.zookeeper.namespace property should be different for the hive-site.xml in the Spark and Hive directories.

Restart the Spark Thrift Server to apply the changes following the script in the .sbin directory at /opt/mapr/spark/spark-<spark_version>/ or by running a maprcli command on all configured nodes:
```
./sbin/stop-thriftserver.sh
./sbin/start-thriftserver.sh 
```
or
```
maprcli node services -nodes <host_1>,<host_2>,<host_n> -name spark-thriftserver -action restart
```

Launch the Zookeeper command line interface, and check the Spark Thriftserver znode by running the following commands:

/opt/mapr/zookeeper/zookeeper-<version>/bin/zkCli.sh -server <ip:port of zookeeper instance>
ls /<hive.server2.zookeeper.namespace>

For example:

/opt/mapr/zookeeper/zookeeper-3.4.11/bin/zkCli.sh -server node1.cluster.com:5181
ls /ts2-ts2
[serverUri=node1.cluster.com:2304;version=;sequence=0000000000]

Using Beeline, you can connect to the Spark Thrift Server by using the following string:

beeline> !connect jdbc:hive2://<hostname -f>:5181/default;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=<hive.server2.zookeeper.namespace>;

For example:

./bin/beeline
Warning: Unable to determine $DRILL_HOME
Beeline version 1.2.0-mapr-spark-MEP-6.0.0-1912 by Apache Hive
beeline> !connect jdbc:hive2://node1.cluster.com:5181/default;ssl=true;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=ts2-ts2;auth=maprsasl;
Connecting to jdbc:hive2://node1.cluster.com:5181/default;ssl=true;serviceDiscoveryMode=zooKeeper;zooKeeperNamespace=ts2-ts2;auth=maprsasl;
20/03/29 21:38:19 WARN MaprSaslClient: SASL Server qopProperty: auth-confis different from Client: auth-conf,auth-int,auth.Using Server one
Connected to: Spark SQL (version 2.4.4.0-mapr-630)
Driver: Hive JDBC (version 1.2.0-mapr-spark-MEP-6.0.0-1912)
Transaction isolation: TRANSACTION_REPEATABLE_READ
1: jdbc:hive2://node1.cluster.com:5181/defaul> show databases;
+-----------------+
| databaseName |
+-----------------+
| default             |
+-----------------+
1 row selected (0.11 seconds)

NOTE High availability for the Spark Thrift Server can be used in conjunction with HiveServer2 high availability. For more information about HiveServer2 high availability, see Enabling High Availability for Hive.