I wrote a simple JAVA application which runs as a service. When my application is up and running, I maintain the PID in a file which will be used while stopping the application.
Issue:
When I restart the OS the stop script is not called (not sure how to make this happen) and the old PID is left as it is in the PID file. Now, after reboot (which start my app) when I stop the app using stop script now my stop script will try to clean up all the PID listed in the file. Most of the time, I will get "No such process". But there are chance the same PID might have been used for some other process
Question:
How I can make sure my stop script will be invoked when I shutdown ore reboot the OS? I am looking a solution for RHEL environment.
I think your are looking for a init script. (startup/shutdown services at different run levels)
This is a good reference
http://blog.rimuhosting.com/2009/09/30/one-java-init-script/
this has a good refernce to Linux init.d scripts
http://coreymaynard.com/blog/creating-a-custom-initd-script-on-fedora/
Hope it helps
If you are looking for scripts that run after reboot, I guess you can write the script in /etc/rc.local and then you can start your service.
This script will run after all your init scripts have run while your machine starts. Using this you can delete the old PID file.
Related
I try to execute a java application at startup in a yocto based linux device. I added a script at /etc/init.d/etic and made it executable. If I call at the shell /etc/init.d/etic start or /etc/init.d/etic stop the application is started an stopped as expected. Then I called on the shell update-rc.d etic defaults and the symlinks were created. According to what I found on the web, this should be enough, but somehow the application is not started. What did I miss? How could I check what is going wrong or is there any minimal example which should work which I can try to extend?
Well, often such issues are due to a different environment when executing the start script by hand, as compared to when it's being run from the init system. For instance, your .profile and .bashrc won't have been sourced, when running from the init system.
You can use eg logger to easily log things from your init-script, and this rather easily find out what goes wrong.
I have a custom version of CENTOS that I need to run a perl script as a daemon in at all times.
To do this I want to get it to run on startup as a daemon.
When the machine is on I can daemonize the script with the command
daemonize /var/myfolder/myscript.pl
And this works fine.
So I have an rc1 script which has a number of commands that run when the machine starts, and the very last line in it is where I try to daemonize that script. Everything else in the rc1 script runs fine, and the script doesn't output any errors, however when I check to see if the daemon is running on start up, it isn't running.
Is there another way that I can get the script to run on startup? Or any ideas on why this method doesn't work?
Proc::Daemon offers what you're looking for.
See this previously asked question: How can I run a Perl script as a system daemon in linux?
The problem was that #INC hadn't fully loaded all of the modules by the time my script was called, and so my daemon wasn't running. I used the PERL5LIB command to add the appropriate directories.
PERL5LIB='/perl:/custom/lib:/usr/local/lib64/perl5' /var/myfolder/myscript.pl &
where /perl; /custom/lib and /usr/local/lib64/perl5 are the directories which were missing from #INC
I have written up a simple bash script that will copy the newest image from my ip camera into a directory, rename the file and delete the old file. The script loops every 10 seconds.
I want to have this script start running in the background and run continuously all the time that the server is up.
I understand the part about adding a & to the end of the command will cause it to run in the background.
Is init.d the best place to execute this?
I am running ubuntu server.
This sort of thing is normally done by service scripts, which you would find under /etc/init.d. Depending on the version, that might be a "System V init script", or one of the systemd scripts.
A simple service script of the sort you are asking about would start automatically (based on comments in the script's header that tell what run-levels it would use), create a file under /var/run telling what process-id the script uses (to allow killing it), and run the copying in a loop, calling sleep 10 to space the timing as indicated.
A typical service script should implement "start", "stop", "restart" and "status". Not all do, but there is rarely a good reason to not do this.
On my (Debian) system, there is a README file in the directory which is a good introduction to the topic. There are several tutorials available for the topic. Here are a few:
Linux: How to write a System V init script to start, stop, and restart my own application or service
Writing a Linux Startup Script
Manage System Startup and Boot Processes on Linux with Upstart
I am trying to start GUI application with upstart script on CentOS. I have test script located /etc/init/ folder.
start on desktop-session-start
stop on desktop-shutdown
respawn
script
export DISPLAY=:0
sleep 5
exec /.1/Projects/UpstartTest/start.sh &
end script
start.sh scripts is running binary files for GUI application.
After reboot my computer. When I typed:
[root#mg-CentOS ~]# initctl status test
test stop/waiting
So my upstart is not runnig. When i type
initctl start test
manually it works fine without any problem.
How can I run this upstart script after user login (desktop started) ? I am trying to find detailed documents for CentOS for upstart but there is no.
For this purpose, you can use the update-rc tool, which is builtin on linux distributions. It basically creates a symbolic link for the script you want to be executed at startup, or some other OS states, on the folder rc.X, where X is the number of the folder that determines a state that you want.
You may want to have a look at this answer: Update-rc.d custom script running too late, and also runs at shutdown
More information about can be found here:
http://www.linux.com/news/enterprise/systems-management/8116-an-introduction-to-services-runlevels-and-rcd-scripts
Detailed information about the CentOS booting process can be found here: https://www.centos.org/docs/5/html/Installation_Guide-en-US/s1-boot-init-shutdown-process.html;
the rc is being explained at this document as well.
i want to run my application on board(i.MX233 EVK) after all modules loaded.i want to add auto log-in.i got this link but the procedure not working.
Running a script after startx automatically
where can i add small script to load my application(C language) automatically after boot-up of board.
Your question has been literally answered million times on Internet. Please have a look at How to run a shell script at startup for instance.
Put your script in /etc/init.d/rcS or rc file init process will automatically execute it.
/etc/init.d/rcS
your_script.sh &