统计jvm的YGC和FGC

因为需要测试jvm 的性能，需要收集YGC和FGC等性能数据，写了个脚本来统计5分钟的情况。

#!/bin/bash
################################
DELTA=3  #print each DELTA seconds
TTIME=18 #total time
MYPID=$$
usage(){
        echo "usage:"
        echo -e "\t$0 -d gap_time -t total_time"
        echo -e "\tthe unit is seconds, not subsecond."
}
while getopts d:t:n: ARGS
do
        case $ARGS in
        t)
                TTIME=$OPTARG
                ;;
        d)
                DELTA=$OPTARG
                ;;
        *)
                usage
                exit 1
                ;;
        esac
done
if [ $TTIME -lt $DELTA ]; then
        echo "gap_time must less than  total_time!"
        exit 2
fi
FLAG=$(( TTIME % DELTA ))
if [ $FLAG -ne 0 ]; then
        echo "total_time/gap_time ==0 !"
        exit 3
fi
N=$(( TTIME / DELTA ))
DELTA=$(( 1000 * DELTA ))
TTIME=$(( 1000 * TTIME ))
PFLAG=$(ps aux|grep java|grep -v -E 'grep|agent'|grep 'Xms'|awk '{print $2}'|wc -l)
if [[ $PFLAG > 1 ]];then
      echo "find more than 1 java process,exit"
      exit 1
fi
PID=$(ps aux|grep java|grep -v -E 'grep|agent'|grep 'Xms'|awk '{print $2}')
if  [ -d /proc/$PID ] ;then
        echo -e "\e[31mjava pid is $PID\e[m"
else
        echo -e "\e[32mcan't find java process!\e[m"
        exit 2
fi
jstat -gc  $PID $DELTA 2>&1 |awk \
'BEGIN {
        M="'$N'"
        i=0
        times=0

}
NR>1{
        ygc[i]=$11
        ygct[i]=$12
        fgc[i]=$13
        fgct[i]=$14
        #print "M=",M,"i=",i
        if(i==0){
            printf("YGC\tYGCT\tFGC\tFGCT\n")
        }
        printf("%s\t%s\t%s\t%s\n",ygc[i],ygct[i],fgc[i],fgct[i])
        if(++i - M >0) {
                times++
                printf("#########in %d subseconds#############\n","'$TTIME'")
                printf("\tYGC=%s\n",ygc[M]-ygc[0])
                printf("\tYGCT=%s\n",ygct[M]-ygct[0])
                printf("\tFGC=%s\n",fgc[M]-fgc[0])
                printf("\tFGCT=%s\n",fgct[M]-fgct[0])
                printf("##########################################\n")
                system("date '+%Y_%m_%d_%T'")
                i=0
        }
}'