Add a message on how to make log refresh immediately when starting a component
### Motivation
Some users may confuse by pulsar/bookie log without flushing immediately.
### Modifications
Add a message in `bin/pulsar-daemon` when starting a component.
@@ -151,6 +151,7 @@ case $startStop in
rotate_out_log $out
echo starting $command, logging to $logfile
+ echo Note: Set immediateFlush to true in conf/log4j2.yaml will guarantee the logging event is flushing to disk immediately. The default behavior is switched off due to performance considerations.
pulsar=$PULSAR_HOME/bin/pulsar
nohup $pulsar $command "$@" > "$out" 2>&1 < /dev/null &
echo $! > $pid
