Step 1: Configure Drill

Drill configuration under Drill-on-YARN differs from Drill configuration under Warden. You must create a site directory to contain the site-specific files for Drill. Drill-on-YARN copies the site directory to every node so that each node has the configuration settings. Having a site directory also simplifies upgrades because you can just delete the old Drill distribution and install the new one while the site-specific files remain unchanged in the site directory.

As of Drill 1.8, the drill-env.sh file contains only custom configurations. MapR-specific configuration settings reside in distrib-env.sh, a file separate from the site-specific settings. When you migrate an existing Drill installation to run under YARN, you must modify the drill-env.sh to remove the Drill and MapR settings, leaving only your site-specific settings.

When you finish configuring Drill, use the site directory to test Drill, including starting, checking status, and stopping Drill.

NOTE: If you installed the mapr-drill-yarn package on nodes other than the Drill-on-YARN client in order to make SQLLine accessible to users, the site directory must be accessible from all nodes. You can copy the configurations across all the nodes, as you did when you ran Drill under the Warden service. Alternatively, you can put the site directory in a shared file system nfs mount to extend the configuration. When users launch SQLLine, they should provide the ZooKeeper connection string to launch Drill.

Create the Site Directory

To create the “site” directory, complete the following steps as the same user that installed Drill and will run the Drill-on-YARN client application:

Create the site directory and an environment variable for the directory:
```
export DRILL_SITE=/opt/mapr/drill/site
mkdir $DRILL_SITE
```
NOTE: The variable is not required and used for convenience in the documentation.
Copy the drill-env.sh, drill-override.conf, drill-on-yarn.conf, and distrib-env.sh files from $DRILL_HOME/conf/ into the site directory. In the following example, $DRILL_HOME is the location of the new Drill installation (usually /opt/mapr/drill/drill-<version>).
```
cp $DRILL_HOME/conf/drill-override.conf $DRILL_SITE
cp $DRILL_HOME/conf/drill-env.sh $DRILL_SITE
cp $DRILL_HOME/conf/drill-on-yarn.conf $DRILL_SITE
cp $DRILL_HOME/conf/distrib-env.sh $DRILL_SITE
```
NOTE: Copy any configuration changes from drill-env.sh file in the previous Drill installation over to the drill-env.sh file in the site directory. Do not include the memory settings when you copy over your previous configurations. These changes must be made in the drill-on-yarn.conf file described in Step 3: Configure YARN to Run Drill.
NOTE: Never modify distrib-env.sh. The distrib-env.sh script contains MapR settings that you should not change. You copy this file to the site directory because it often contains values set during Drill installation. When you upgrade Drill, replace the file with the latest version from $DRILL_HOME/conf.
If you developed custom code (data sources or user-defined functions), place the Java JAR files in $DRILL_SITE/jars. If you have code from your prior Drill installation, copy the JAR files from $PREV_DRILL/jars/3rdparty to $DRILL_SITE/jars.
```
cp $PREV_DRILL/jars/3rdparty/yourJarName.jar $DRILL_SITE/jars
```
NOTE: Copy only the JAR files that you added. Do not copy JAR files that shipped with the prior Drill version.
Add native libraries to the site directory. If you used a native library, such as the JPAM library, in prior versions of Drill, place the native libraries in $DRILL_SITE/lib to enable YARN to automatically copy (localize) them to each node that runs Drill.
```
cp native_libraries $DRILL_SITE/lib
```

Modify the drill-env.sh File

Copy any configuration changes from drill-env.sh file in the previous Drill installation over to the drill-env.sh file in the site directory. Memory settings under Drill-on-YARN are now part of the drill-on-yarn.conf file. Modify the memory settings in $DRILL_SITE/drill-env.sh, as shown below, to ensure that the Drill memory settings match the amount of memory that Drill-on-YARN requires.

To modify drill-env.sh, complete the following steps:

Review each line in $PREV_DRILL/conf/drill-env.sh for settings you added, and copy them into the new $DRILL_SITE/drill-env.sh file.
NOTE: If you do not recall whether you customized settings, you can compare your file with the original version of drill-env.sh that shipped with the prior Drill version.
Locate the following lines in drill-env.sh and note the values:
```
DRILL_MAX_DIRECT_MEMORY="<value>"
DRILL_HEAP="<value>"
```
Replace those lines with the following lines, substituting the values in the new lines with the values from the old lines:
```
export DRILL_MAX_DIRECT_MEMORY=${DRILL_MAX_DIRECT_MEMORY:-"<value>"}
export DRILL_HEAP=${DRILL_HEAP:-"<value>"}
```
NOTE: If you do not intend to run Drill outside of YARN, you can remove the two lines shown above from drill-env.sh.
NOTE: If you do not make this change, Drill ignores the memory settings in the drill-on-yarn.conf file. If you are installing Drill fresh, and do not have an existing file, you can skip this step. Files in Drill 1.8 and later have the correct format.
NOTE: When you install Drill, the MapR installer automatically adds the HADOOP_HOME variable, which points the current MapR-provided Hadoop to your distrib-env.sh. If HADOOP_HOME is located elsewhere, change this location in drill-env.sh

Use the Site Directory to Test Drill

You will use the site directory each time you start Drill using the --site or --config option. Use the option to verify that the configuration works by starting Drill as a stand-alone service on a single node.

drillbit.sh --site $DRILL_SITE start

Wait a few seconds and then verify that Drill continues to run:

drillbit.sh --site $DRILL_SITE status

You can also use the Drill Web Console for the Drillbit to verify that Drill has the proper settings. Once satisfied that the configuration is connect, stop Drill:

drillbit.sh --site $DRILL_SITE stop

NOTE: If you find that specifying the --site option becomes tedious, you can set the DRILL_CONF_DIR variable in your environment:

export DRILL_CONF_DIR=”$DRILL_SITE”
drillbit.sh start