Add HBase RegionServer

Install HBase, ZooKeeper, add the HDP repository, and copy the HBase configurations to the new slave nodes.

Use the following instructions to manually add HBase RegionServer hosts:

On each of the new slave nodes, install HBase and ZooKeeper.
- For RHEL/CentOS/Oracle Linux:
```
yum install zookeeper hbase 
```
- For SLES:
```
zypper install zookeeper hbase 
```

On each of the new slave nodes, add the HDP repository to yum:

RHEL/CentOS/Oracle Linux 6.x:

wget -nv http://public-repo-1.hortonworks.com/HDP/centos6/2.x/updates/2.3.0.0/hdp.repo -O /etc/yum.repos.d/hdp.repo

RHEL/CentOS/Oracle Linux 7.x:

wget -nv http://public-repo-1.hortonworks.com/HDP/centos7/2.x/updates/2.3.0.0/hdp.repo -O /etc/yum.repos.d/hdp.repo

SLES SP3/SP4:

wget -nv http://public-repo-1.hortonworks.com/HDP/suse11sp3/2.x/updates/2.3.0.0/hdp.repo -O /etc/zypp/repos.d/hdp.repo

Copy the HBase configurations to the new slave nodes and set appropriate permissions.

Option I: Copy HBase config files from an existing slave node.

On any existing slave node, make a copy of the current configurations:

tar zcvf hbase_conf.tgz /etc/hbase/conf 
tar zcvf zookeeper_conf.tgz /etc/zookeeper/conf

Copy these files to each of the new nodes:

rm -rf /etc/hbase/conf
mkdir -p /etc/hbase/conf
cd /
tar zxvf $location_of_copied_conf_tar_file/hbase_conf.tgz
chmod -R 755 /etc/hbase/conf

rm -rf /etc/zookeeper/conf
mkdir -p /etc/zookeeper/conf
cd /
tar zxvf $location_of_copied_conf_tar_file/zookeeper_conf.tgz
chmod -R 755 /etc/zookeeper/conf

Option II: Manually add Hadoop configuration files.

On all of the new slave nodes, create the configuration directory, copy all of the configuration files, and set the permissions:
```
rm -r $HBASE_CONF_DIR ;
mkdir -p $HBASE_CONF_DIR ;
```
Copy all of the configuration files to $HBASE_CONF_DIR
```
chmod a+x $HBASE_CONF_DIR/;
chown -R $HBASE_USER:$HADOOP_GROUP $HBASE_CONF_DIR/../ ;
chmod -R 755 $HBASE_CONF_DIR/../
```
```
rm -r $ZOOKEEPER_CONF_DIR ;
mkdir -p $ZOOKEEPER_CONF_DIR ;
```
Copy all of the configuration files to $ZOOKEEPER_CONF_DIR
```
chmod a+x $ZOOKEEPER_CONF_DIR/;
chown -R $ZOOKEEPER_USER:$HADOOP_GROUP $ZOOKEEPER_CONF_DIR/../ ;
chmod -R 755 $ZOOKEEPER_CONF_DIR/../
```
where:
- $HBASE_CONF_DIR is the directory to store the HBase configuration files. For example, /etc/hbase/conf.
- $HBASE_USER is the user owning the HBase services. For example, hbase.
- $HADOOP_GROUP is a common group shared by services. For example, hadoop.
- $ZOOKEEPER_CONF_DIR is the directory to store the ZooKeeper configuration files. For example, /etc/zookeeper/conf
- $ZOOKEEPER_USER is the user owning the ZooKeeper services. For example, zookeeper.

Start HBase RegionServer node:

<login as $HBASE_USER>
/usr/lib/hbase/bin/hbase-daemon.sh --config $HBASE_CONF_DIR start regionserver

On the HBase Master host machine, edit the /usr/lib/hbase/conf file and add the list of slave nodes' hostnames. The hostnames must be separated by a newline character.