=== Flume Environment Variables

This section describes several environment variables that affect how
Flume operates.  The +flume+ script in +./bin+ uses these system
environment variables.  Many of these variables are set by the
+flume-daemon.sh+ script used when flume is run as a daemon.

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+FLUME_PID_DIR+ :: The directory where a flume node or flume
master will drop pid files corresponding to the daemon process.

+FLUME_CLASSPATH+ :: The custom java classpath environment variable
additions you want flume to run with.  These values are prepended to
the normal Flume generated CLASSPATH.  WARNING: The +flume+ script
overwrites the standard CLASSPATH when it is executed.

+FLUME_LOG_DIR+ :: The directory where debugging logs
generated by the flume node or flume master are written.

+FLUME_LOGFILE+ :: This sets the suffix for the logfiles generated by
flume node or flume master.

+FLUME_ROOT_LOGGER+ :: The log4j logging setting for the executing
command.  By default it is "INFO,console".

+ZOOKEEPER_ROOT_LOGGER+ :: The log4j logging setting for a master's
embedded zookeeper server's logs.  By default it is "ERROR,console".

+WATCHDOOG_ROOT_LOGGER+ :: The log4j logging setting for the logging
the watchdog that wraps flume nodes and flume masters generates.  By
default it is "INFO,console".

+FLUME_CONF_DIR+ :: The directory where the +flume-site.xml+ and
+flume-conf.xml+ files flume node and flume master will use reside.
This defaults to +./conf+ if a +./conf/flume-conf.xml+ file is found,
or to +/etc/flume/conf/+ if it +flume-conf.xml+ is found there.

+HADOOP_HOME+ :: The directory where Hadoop jars are expected to be
found.  If not specified it will use jars found in +/usr/lib/hadoop+
or +./lib/+.

+FLUME_DEVMODE+ :: If this value is set to "true" the +./libbuild+
jars which include ant jars required to compile JSP servlets will be
included in the CLASSPATH.

+FLUME_VERBOSE+ :: If it this is toggled, the flume script will print
out the command line being executed.

+FLUME_VERBOSE_JAVA+ :: If this is toggled along with FLUME_VERBOSE,
the "-verbose" flag will be passed to the JVM running flume.

+LD_LIBRARY_PATH+ :: Populate with a : separated list of file paths to
extend the java.library.path aspect of Flume. This allows you to include 
native libraries in the java lookup path. Example usage would be with Lzo
where you need to extend the path with the Lzo C libraries contained in your
Hadoop install.