#!/bin/bash
 
 # **tools/dstat.sh** - Execute instances of DStat to log system load info
 #
 # Multiple instances of DStat are executed in order to take advantage of
 # incompatible features, particularly CSV output and the "top-cpu-adv" and
 # "top-io-adv" flags.
 #
 # Assumes:
 #  - dstat command is installed
 

 # Retrieve log directory as argument from calling script.

 LOGDIR=$1
 
 # Command line arguments for primary DStat process.

 DSTAT_OPTS="-tcmndrylpg --top-cpu-adv --top-io-adv --top-mem --swap --tcp"

 
 # Command-line arguments for secondary background DStat process.

 DSTAT_CSV_OPTS="-tcmndrylpg --tcp --output $LOGDIR/dstat-csv.log"

 
 # Execute and background the secondary dstat process and discard its output.
 dstat $DSTAT_CSV_OPTS >& /dev/null &
 
 # Execute and background the primary dstat process, but keep its output in this
 # TTY.
 dstat $DSTAT_OPTS &
 
 # Catch any exit signals, making sure to also terminate any child processes.
 trap "kill -- -$$" EXIT
 
 # Keep this script running as long as child dstat processes are alive.
 wait