jdt

#!/bin/bash
# Java Dump Tool (jdt), a wrapper of jstack, jmap, jinfo, jstat, and so on
# Used to protect the scene before restart a problematic java application
# Usage: 1. if there is only one running java process, just: jdt
#        2. given a java pid: jdt pid
# Created by zhouwei on 2016-9-18

if (($# >= 2)) ; then
    echo "Usage: jdt [pid]"
    exit 1
fi


print_line() {
    echo ""
    echo "=================================================================================="
    echo ""
}


# get a effective java pid
if [[ "$1" != "" ]]; then
    if ! ps aux | grep -v grep | grep java | awk '{print $2}' | grep "^$1$" >&/dev/null ; then
	echo "ERROR: $1 is not a java pid!"
	exit 1
    fi
    PID="$1"
else  
    num_java_process="$(ps aux | grep -v grep | grep java | wc -l | awk '{print $1}')"
    if [[ "$num_java_process" == "0" ]]; then 
	echo "please provide a pid: jdt pid"
	exit 1
    elif [[ "$num_java_process" == "1" ]]; then
	PID="$(ps aux | grep -v grep | grep java | awk '{print $2}')"
    elif [[ "$num_java_process" -gt "1" ]]; then
	echo "please provide a pid: jdt pid"
	echo "there are multiple java processes, pick one among them:"
	echo ""
	ps aux | head -1
	ps aux | grep -v grep | grep --color=auto java
	exit 1
    fi
fi
echo "starting dump java process: $PID"


# make a dump directory
output_dir="$(pwd)/dump_java_$PID"
[[ -d $output_dir ]] || mkdir -p $output_dir
cd $output_dir


# ps aux, /proc, and top 
echo "starting ps, /proc, and top ..."
exec 3>&1 
exec 1>ps_proc_top.log
echo "date: $(date '+%Y-%m-%d %H:%M:%S')"
print_line

echo "ps aux - java:"
ps aux | head -1 
ps aux | grep -v grep | grep $PID 
print_line

echo "/proc/${PID}/status: "
cat /proc/${PID}/status
print_line

echo "top - java:"
top -b -n 4 -H -p $PID


# jstack (use -F to force a dump when it does not respond, see "man jstack")
exec 1>&3 ; echo "starting jstack ..."
exec 1>jstack.log
jstack $PID 

exec 1>jstack_l.log
echo "jstack -l $PID:"
jstack -l $PID 


# jmap (use -F to force a dump when it does not respond, see "man jmap")
exec 1>&3 ; echo "starting jmap ..."
exec 1>jmap_heap.log
jmap -heap $PID

exec 1>jmap_histo_live.log
jmap -histo:live $PID

# -clstats is for jdk8
exec 1>jmap_clstats.log
jmap -clstats $PID 2>/dev/null

exec 1>jmap_finalizerinfo.log
jmap -finalizerinfo $PID

jmap -dump:live,format=b,file=jmap_dump.bin $PID


# jinfo, print Java system properties and VM flags
exec 1>&3 ; echo "starting jinfo ..."
exec 1>jinfo.log
jinfo $PID


# jstat
exec 1>&3 ; echo "starting jstat ..."
jstat -gc $PID 250ms 20 > jstat_gc.log
jstat -gccapacity $PID 250ms 10 > jstat_gccapacity.log
jstat -gccause $PID 250ms 10 > jstat_gccause.log

jstat -class $PID 250ms 10 > jstat_class.log

jstat -gcnew $PID 250ms 10 > jstat_gcnew.log
jstat -gcnewcapacity $PID 250ms 10 > jstat_gcnewcapacity.log
jstat -gcold $PID 250ms 10 > jstat_gcold.log
jstat -gcoldcapacity $PID 250ms 10 > jstat_gcoldcapacity.log

# -gcmetacapacity is for jdk8
jstat -gcmetacapacity $PID 250ms 10 > jstat_gcmetacapacity.log 2>/dev/null
# -gcpermcapacity is for jdk version <= 7
jstat -gcpermcapacity $PID 250ms 10 > jstat_gcpermcapacity.log 2>/dev/null


exec 1>&3  
exec 3>&-
echo ""
echo "Java Dump Tool (jdt) finished!"
echo "output directory is: $output_dir"
echo ""

exit 0