Develop Reference

kill a java process in Linux

I have a BI application (looker) runs on a linux VM.
tobe able to restart the service, I need to clear the existing java process.
In below screenshot, after run below script, there is a java process, but not showing in the list when I run jps script. What's the reason? and how can I properly terminate this java process?
ps aux | grep java

Have you tried these ?
killall java
or
kill $(pidof java)

As you can see from your image, the process id is changing each time 9287 / 9304 and represents | grep java - and not a java VM!
A common fix is to filter the ps results for not matching | grep -v, such as:
ps aux | grep java | grep -v --regexp=grep.\*java
If there are results above you could append commands to read the process ids and kill command:
kill -TERM $(ps aux | grep java | grep -v --regexp=grep.\*java | awk '{print $2}')
Note: the above will kill all processes with "java" in name so is not very useful if there are multiple java services for same account. You may need to add filter for specific Java VMs.

How to stop the process from running?

This question might be a bit similar to this or this question.
How do I stop a particular .jar file from running in Mac OS? When I open up the activity monitor, it does not show the process listed. But I am sure it is running because when I visit the localhost (I have developed a .jar from a Spring Boot application), I can still see the welcome message!
Could you please let me know how I could stop a particular .jar file from executing? Thanks.

You can use jps to get the pid (and jar name), awk to parse the pid and then kill it. Like, (with bash or similar)
kill -9 $(jps | grep -i "thejar.jar" | awk '{print $1}')
or
kill -9 `jps | grep -i "thejar.jar" | awk '{print $1}'`
The -i option to grep makes it case insensitive. Omit if that is not needed.

Step1: ps -aux | grep xxx, xxx is the name of .jar
Step2: kill -9 pid, pid you can get from the first command.

Getting PID of a process that has just started

I am working on a Gradle Java project. Which starts Tomcat for testing and stops it later.
I am supposed to kill this Tomcat instance when the test fails.
I tried using "ps aux| grep tomcat | grep -v grap | awk {print $2}" command to get the process id and kill the process.
But on Production, there will be so many Tomcat processes running simultaneously by many users, I just want the tomcat process started by my build.gradle for test execution.
So how can I accomplish the task? Please provide me some guidelines.

You need to find a unique string in the output of 'ps aux' which differentiates your test tomcat and others'.
I currently use the below script to run 'shutdown.sh' first and then kill the PID as most of the times, the application stops but the process does not stop.
PID=`ps -ef | grep $JAVA_HOME/bin/java | grep "$TOMCAT_LOC"/conf | grep -v grep | awk '{ print $2 }'`
if [ $PID ]; then
echo tomcat is running with PID:$PID.
# Stop or Kill running Tomcat
if [[ -f $TOMCAT_LOC/bin/shutdown.sh ]]; then
[[ ! -x $TOMCAT_LOC/bin/shutdown.sh ]] && chmod a+x $TOMCAT_LOC/bin/shutdown.sh
$TOMCAT_LOC/bin/shutdown.sh >>/dev/null
sleep 20
fi
kill -9 $PID
sleep 3
else
echo tomcat is not running
fi
You may also look at configuring a PID file by editing the 'catalina.sh' which you can read later to find out your PID.
# CATALINA_PID (Optional) Path of the file which should contains the pid
# of the catalina startup java process, when start (fork) is
# used

Java JRE has tool called jps in $JAVA_HOME/bin folder.
It's similar to unix ps command but for java only.
You can use it to determined exac java process you need.
Using this tool is more recommended and actually it is more useful, when you have more than one java applications is running on your host...
for example I have running h2 database and many other apps, but wanna kill only h2, so I can use jps to get it PID
$ jps
17810 GradleDaemon
17798 GradleWrapperMain
17816 h2-1.4.197.jar
17817 GradleDaemon
17818 GradleDaemon
18011 Jps
16479
and then just kill needed process:
kill -9 17816
and all other java apps will continue work normally. I not sure about tomcat, but I think it can be done in similar way, something like that:
kill -9 $(jps | grep tomcat | awk '{print $1}')
Lastly, little bit offtopic, but a specially to your case: correct way would be using start/stop/restart scripts provided by tomcat

The correct way to terminate a Tomcat instance is via its own shutdown command. You should not be thinking of processes, or PIDs, or kills, at all.

so if you want to kill tomcat from that user from which you have logged in then try following and let me know if this helps you.
ps -ef | grep -v grep | grep `whoami` | grep tomcat
So by ps -ef I am listing all the processes then grep -v grep will remove the grep command's process then grep whoami will look for your currently logged in user then grep tomcat will look only for tomcat process, test it once and if All is Well then you could kill it.
By the way how about tomcat stop script? In case it is there you could use that also.

You can use shell variable $!. It represents the PID of the most recent background command.
yourCommand &
CMD_PID=$!
echo $CMD_PID

Port 8005 Required by Tomcat, already in use

I am attempting to refresh my knowledge of Java. I've downloaded and started using Eclipse Mars. I was following a tutorial that uses Tomcat. I tried to create and start a server. I received the following message in the image: Port 8005 is in use.
I checked and surely it is but I don't know what is using it or how to either stop that process or make Tomcat use another port. Thank you in advance for the help.

Tomcat uses -
8005,8080,8009
Those three ports.
Open up command prompt -
C:\.....>netstat -o -n -a | findstr 0.0:8080
TCP 0.0.0.0:8080 0.0.0.0:0 LISTENING 1220
C:\....\username>taskkill /F /PID 1220
It will kill that task.Try it.

METHOD 1
ps -aef | grep java | grep apache | awk '8005'
list of process running with this port will display with its process id.
pick the process id say 1090.
kill -9 1090
METHOD 2
This will kill all the process with tomcat
kill $(ps -aef | grep java | grep apache | awk '{print $2}')

Jboss 7.1.1 start/stop script

Could someone tell how to start/stop the Jboss-7.1.1 server in MAC using Shell Script.
stop_viewer(){
echo "********* Stopping JBoss Server by killing the process **********";
ps | grep domain.sh | grep -v grep | awk '{print $1}' | xargs kill
ps | grep java | grep -v grep | awk '{print $1}' | xargs kill
ps -ef | grep superuser | grep java | grep -v grep | awk '{print $2}'| xargs kill
echo "********* Stopped JBoss Server by killing the process **********";
}
The above script is working fine in Jboss-7.0.2 to stop the server. But in Jboss-7.1.1, it doesn't stop the server. Please someone help to solve this.

1) First you need to have JBoss downloaded. (I assume you already have valid Java version installed).
2) Once it is downloaded, unzip the folder:
cd /Users/eugene/Downloads
mkdir JBOSS-7
cp /Users/eugene/Downloads/jboss-as-7.1.1.Final.zip /Users/eugene/Downloads/JBOSS-7
cd /Users/eugene/Downloads/JBOSS-7
unzip /Users/eugene/Downloads/jboss-as-7.1.1.Final.zip
3)
cd Users/eugene/Downloads/JBOSS-7/jboss-as-7.1.1.Final/bin
./standalone.sh
If you want to stop it:
ctrl + c
of course your path may be different. If you want to run it in background, then just do:
./standalone.sh &
Stopping it :
ps -ef | grep jboss
You will get an output close to this one:
eugene#eugenes-MacBook-Pro ~/D/J/j/bin> ps -ef | grep jboss
501 1471 1446 0 1:32AM ttys000 0:03.31 /usr/....
And then issue:
kill -9 1471
Finally with JBoss CLI you can execute:
./jboss-cli.sh --connect ":shutdown"
EDIT
The Script seems to do it's job, all you have to do is edit it a bit:
#!/bin/sh
echo "********* Stopping JBoss Server by killing the process **********";
ps -e | grep jboss | grep -v grep | awk '{print $1}' | xargs kill
echo "********* Stopped JBoss Server by killing the process **********";
Notice that I removed a few lines and changed java with jboss
Put this in a file called stopJboss.sh
Then :
sudo chmod +x stopJBoss.sh
Then invoke it when needed:
./stopJBoss.sh
This will work only if you have a single instance of JBoss running, for more you will need a different script.
P.S. I am not a guru in scripting but here is what this line does:
ps -e | grep jboss | grep -v grep | awk '{print $1}' | xargs kill
It is going to look for every process that contains the jboss keyword. But it also going to output the grep command itself, thus you will get an output of two commands, but you need only the first one.
You could run ps -e | grep jboss and see that the output contains two lines and not one.
That is why you invoke grep -v grep - which means : in those two lines found grep for "grep" but invert the result, in this way you omit the second unneeded result.
Then awk '{print $1}' splits the string into tokens and takes the first one, which is the PID that you need and then you pass this PID to the kill command using the xargs command.

To shutdown the server via command line
sh ./bin/jboss-cli.sh --connect command=:shutdown
assuming you are running on localhost and using the default native management port i.e. 9999
if not you need to specify the IP (jboss.bind.address) and the native management port(jboss.management.native.port) configured in standalone.xml
sh ./bin/jboss-cli.sh --connect controller=<IP>:<native-mgmt-port> command=:shutdown

This is how I do it:
ps -ef | grep jboss | grep -v grep | awk '{print $2}' | xargs kill -9
I have this in a bash file that i call killjboss and it works well with me.

After dive on the Google, i managed to put this work:
#!/bin/sh
### BEGIN INIT INFO
# Provides: jboss
# Required-Start: $local_fs $remote_fs $network $syslog
# Required-Stop: $local_fs $remote_fs $network $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start/Stop JBoss AS v7.1.1
### END INIT INFO
#
#source some script files in order to set and export environmental variables
#as well as add the appropriate executables to $PATH
export JAVA_HOME=/usr/lib/jvm/java-7-oracle
export PATH=$JAVA_HOME/bin:$PATH
export JBOSS_HOME=/home/gaspar/jboss-as-7.1.1.Final
export PATH=$JBOSS_HOME/bin:$PATH
case "$1" in
start)
echo "Starting JBoss AS 7.1.1"
#original:
#sudo -u jboss sh ${JBOSS_HOME}/bin/standalone.sh
#updated:
start-stop-daemon --start --quiet --background --chuid jboss --exec ${JBOSS_HOME}/bin/standalone.sh
;;
stop)
echo "Stopping JBoss AS 7.1.1"
#original:
#sudo -u jboss sh ${JBOSS_HOME}/bin/jboss-admin.sh --connect command=:shutdown
#updated:
sudo -u jboss sh ${JBOSS_HOME}/bin/jboss-cli.sh --connect command=:shutdown
;;
*)
echo "Usage: /etc/init.d/jboss {start|stop}"
exit 1
;;
esac
exit 0
:)