[SOLVED] Shell script leaving process after successful execution

Issue

I wrote a shell script which inturn calls other schell scripts using nohup. After the successful completion of the script, I still see Linux process running for the custom script I wrote.

contents of startAllComponents.sh

start_Server()
{   
SERVER_HOME=${1}
NOHUP_LOG_FILE=${2}
logmsg "Starting the server"
/usr/bin/nohup `${SERVER_HOME}/bin/server.sh >> ${NOHUP_LOG_FILE} 2>&1 ` &
sleep 5 
PID=`ps -ef|grep ${SERVER_HOME}/jvm |grep -v grep| awk '{print $2}'`        
if [ "${PID}" = "" ]
then                
logmsg "Couldn't get the PID after starting the server"
else             
logmsg "****** Server started with PID: ${PID} ****** " 
fi
}

logmsg()
{
echo  "`date '+%b %e %T'` : $1"$'\n' >> /tmp/STARTUP`date '+%Y%m%d'`_.log
}

#### Send an email #####
sendEmail()
{               
RECIPIENTS="[email protected]" 
SMTP="1.1.1.1:25"
mailx -s "$SUBJECT" -S "smtp=smtp://$SMTP" $RECIPIENTS < /tmp/STARTUP`date '+%Y%m%d'`_.log
}

##### Main #####
INTS[0]="/opt/server/inst01;/home/gut1kor/nohup.inst01.out"
INTS[1]="/opt/server/inst02;/home/gut1kor/nohup.inst02.out"
INTS[2]="/opt/server/inst03;/home/gut1kor/nohup.inst03.out"

echo "##### Bringing up servers on `hostname`. #####"$'\n' > /tmp/STARTUP`date '+%Y%m%d'`_.log

IS_TOTAL=${#INTS[@]}

logmsg "Total Servers are: ${IS_TOTAL}"

if [ "$IS_TOTAL" -gt "0" ]
then
for((i=0;i<IS_TOTAL;i++)) do
IFS=";" read -a arr <<< "${INTS[$i]}"
start_Server ${arr[0]} ${arr[1]}
done
fi
sendEmail

The script works as expected in bringin up the server instances but after the execution I see two processes for the script running for each instance.

[gut1kor@HOST1 startAll]$ ps -ef|grep startAllComponents.sh
gut1kor      63699     1  0 18:44 pts/2    00:00:00 /bin/sh ./startAllComponents.sh
gut1kor      63700 63699  0 18:44 pts/2    00:00:00 /bin/sh ./startAllComponents.sh
gut1kor      63889 61027  0 18:45 pts/2    00:00:00 grep startAllComponents.sh

Why these processes are still there even after the script execution is done? What changes should I make in the script?

Solution

It is mostly like due to the use of nohup utility. The problem with the using the command is, it forks a new process every time it is invoked from start_Server() function call.

From the man page

 nohup   No Hang Up. Run a command immune to hangups, runs the given 
         command with  hangup signals ignored, so that the command can 
         continue running in the background after you log out.

To kill all the process started by nohup you probably need to get the process id of the command started and kill it at the end of the script.

 /usr/bin/nohup $( ${SERVER_HOME}/bin/server.sh >> ${NOHUP_LOG_FILE} 2>&1 ) &
 echo $! >> save_pid.txt       # Add this line 

At the end of the script.

 sendEmail

 while read p; do
 kill -9 $p
 done <save_pid.txt

Answered By - Inian

Answer Checked By - Mildred Charles (WPSolving Admin)