How to enable MapRFS client debug in Drill

Goal:

This article explains how to enable MapRFS client debug in Drill so that Drill can print much more verbose logs in drillbit.out.

Solution:

1. Put below entry into $DRILL_HOME/conf/core-site.xml on all drillbit nodes.

For example, if it is Drill 1.4 on MapR, then the location is:
/opt/mapr/drill/drill-1.4.0/conf/core-site.xml

<property>
    <name>fs.mapr.trace</name>
    <value>debug</value>
</property>

2. Restart all drillbits.

3. Check the debug logs in drillbit.out

For example, if we create a table in Drill, below information may show up:

DEBUG Client fs/client/fileclient/cc/client.cc:3770 Thread:
DEBUG Cidcache fs/client/fileclient/cc/cidcache.cc:360
DEBUG JniCommon fs/client/fileclient/cc/jni_MapRClient.cc:3115
...etc...