· Check if the JAVA process is running using following command
ps aux | grep java
It will show following output
"root 2929 39.1 5.0 3323548 204140 pts/0 Sl+ 12:51 0:09 java -D[Standalone] -server -Xms64m -Xmx2048M -XX:MaxPermSize=256m -XX:NewRatio=2 -XX:PermSize=64m -XX:+UseG1GC -noverify -Djava.net.preferIPv4Stack=true -Djava.util.Arrays.useLegacyMergeSort=true -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=false -Dorg.jboss.boot.log.file=/root/wildfly/standalone/log/server.log -Dlogging.configuration=file:/root/wildfly/standalone/configuration/logging.properties -jar /root/wildfly/jboss-modules.jar -mp /root/wildfly/modules org.jboss.as.standalone -Djboss.home.dir=/root/wildfly -Djboss.server.base.dir=/root/wildfly/standalone"
· In the above output the one that is marked with yellow is the process ID of the JAVA.
· To kill the Wildfly process run this command
kill -9 2929
· After executing above command run the "ps aux | grep java" again to verify that there is no JAVA process running
· The output should look like below which show that no JAVA process is running
"root 3037 0.0 0.0 13592 912 pts/1 S+ 13:00 0:00 grep --color=auto java"
2. Finding JDK location in Linux
· Execute the following command to find the JAVA Installed in the Linux
find / -name java
The above command will show following output depending upon the flavor of the Linux
· From the above output you have to look for line containing the oracle, that will be your JDK installed path.
· After you have found out JDK installed path you can now set JAVA environment variable, that will configure all JAVA application to use default JDK.
3. Command to remove tmp folder and empty log folder in Linux
· When you upgrade your Elegant JBI version or you have made some change in the EJBI data folder , sometime the changes are not reflected. In that case you need to delete temporary folder and restart Wildfly server.
· Log files takes up lot of disk space so it is good practice to delete the log files on regular basis.
· To delete Wildlfy tmp folder execute following command
cd WILDFLY_HOME/standalone ( To change the directory path)
rm -rf tmp
· To delete Data tmp folder execute following command
cd WILDFLY_HOME/standalone/deployments/elegantjbi.war/data ( To change the directory path )
rm -rf temp
· To delete the contents of the Wildfly Log folder execute following command.
cd WILDFLY_HOME/standalone/log ( To change the directory path )
rm -rf *
· To delete the contents of the Data log folder execute the following command
cd WILDFLY_HOME/standalone/deployments/elegantjbi.war/data/logs ( Change the Directory path )
rm -rf *
· To empty the contents of the log files execute the following command
cat /dev/null > logfile
4. Command to view log files in real time.
· You need to monitor the log files for errors. To view the log file in real time i:e the file is constantly changed as log is generated. To do this you have to use tail command available in Linux
· You can view last logs of file using tail command
tail -f logfile
· The above command will display only last 10 lines of log file , but suppose you need to view last 500 lines you can execute below mention command
tail -500f logfile
5. To view current port binding and TCP/IP Protocol used in Linux
· Your Wildlfly server is bind to particular port for example 80 , 8080 and so on. Bind port will be used to access Elegant JBI URL.
· In some cases you server is running multiple applications and if they are running on the same port as wildfly server, In that case wildfly server will throw HTTP listener error and will not start.
· To resolve the above issue you need to first check that the ports configured in Wildfly server is not used by other application.
· To do that run below mention commands.
netstat -tulnp | grep 80 ( Here we are checking if some application is utilizing port 80)
You will get following output if any application is configured to use port 80
As you can see from above output 80 port is being used by nginx web server and port 8080 is being used
JAVA (WIldfly) server.
To check you have to view the "Listening" parameter which show that port 80 and port 8080 is being used by some application
· In general to will all the ports used you can simply run " netstat -anb " or " netstat -tulnp " command without pipe parameter.
6. Create or Extract tar/zip folder in Linux
· In case there is no GUI available in Linux and you need to create backup of your current Elegant JBI version or Data folder. You can use tar or zip command to create compressed folder.
· To create tar use following command
tar -cvf output.tar /directory
For eg:- tar -cvf wildfly.tar /wildfly
· To extract the tar file use following command
tar -xzf wildfly.tar
· To extract the zip folder use following command
7. To view system resources utilization
· We need to view the CPU, RAM and other processes utilization
· "Top" command will display all the system resources
· You can view following parameter such as %CPU , % MEM utilization and how much memory is used by the processes.
· To view details in more human readable format you can use "htop" command.
· You have to installed "htop" utility in Linux
Installed htop in Debian based Linux (Ubuntu)
apt-get install htop
Installed htop in RPM base Linux ( Cent OS , Red Hat and Fedora )
Please refer the following URL to install "htop" in RPM based Linux
· You will get following output using "htop" command
· You can see the difference as "htop" command provides more detail information in human readable format.
8. Basic Commands in Linux
· To Rename folder in Linux
For e.g. we need to rename wildlfy folder to wildfly_old
mv wildfly wildfly_old
· To copy recursively in Linux
For e.g we need to copy wildfly folder contents to another location (/home)
cp -R wildfly/ /home/
· To Move folder to different location
For e.g you need to move wildfly folder to another location (/home)
mv wildfly_old /home
· To list folders Contents in Linux
For e.g To list the contents of wildfly folder
ls -al wildfly
· To view size of folder or file in Linux
For e.g To view size of Wildfly folder
du -sh wildfly
To view size of stanalone.xml file
du -sh standalone.xml
· To change ownership of folder/file in Linux
For e.g. To change the ownership of folder/file in Linux
chown -R root:root wildfly
· Restart Linux server using Terminal
· Changing permission of folder/files in Linux
For e.g. You want to give Read/Write/execute permission to particular folder or file in Linux
chmod -R 755 wildfly (This will give R/W/E permission to owner and R/W permission to other and group)
chmod -R 777 wildlfy (This will give R/W/E permission to owner, other and group)
chmod -R 644 wildfly (This will give R/W permission to owner and R permission to other and group)
· View Hard Disk space in Linux
df -h (This will display size according to the partition)
fdisk -l | grep Disk (This will display total HDD size)
· To check Memory size in Linux
Note: This article is based on ElegantJ BI Version 4.1. This may or may not be relevant to the ElegantJ BI version you may be using.