What happens when we double click an application at OS level. I understand that this is highly OS dependent. But i think that in windows
The currently executing process will fork() a new child process and the Process Control Block of the newly created child process will be initialized with the data required for the application and the new process would be scheduled or would be executed immediately
Any suggestions.
Thanx in advance
Like fork() on linux , we have CreateProcess on windows. Similarly all the initialization will happen ... for more details you can refer http://msdn.microsoft.com/en-us/library/ms682425(v=vs.85).aspx. Like in linux we use command ps to list the running processes , here in windows we have tasklist.
Related
I have a process in windows which i am running in startup. Now i need to make it if somehow that process get killed or stopped i need to restart it again in Windows 10?
Is there any way. Process is a HTTP server which if somehow stopped in windows i need to restart it. I have tried of writing a power-shell in which I'll check task-list status of process and then if not found I'll restart but that is not a good way. Please suggest some good way to do it.
I have a golang exe; under a particular scenario my process got killed or stopped i need to start it up again automatically. This has to be done imediately after the exe got killed. What is the best way to achieve this?
I will give you a brief rundown. You can enable Audit Process Termination in local group policy of the machine as shown below. In your case, success audits would be enough. Please note that the pic is for Windows 7. It may change with OS.
Now every time a process gets terminated, a success event will be generated and written to the security eventlog.
This will allow you to create a task scheduler that triggers on the generation of this event that calls a script that would run the process again. Simple right?
Well, you might have some trouble setting that task up especially when you want to pass details about the generating event to the script. This should help you get through that.
You can user Task scheduler for this purpose. There is a option of "restart on failure" which can be selected and whenever your process get failed it will restart again.
Reference :- https://social.technet.microsoft.com/Forums/windowsserver/en-US/4545361c-cc1f-4505-a0a1-c2dcc094109a/restarting-scheduled-task-that-has-failed?forum=winserverManagement
If I run the following command in my session...
(Get-Process -Id $pid).CloseMainWindow()
I am able to gracefully shut down a process (no modal windows or other popups arise).
If, however, the pid is in another user's session on the same machine (running RDS), the process does not close, and CloseMainWindow() returns FALSE (it returns TRUE if it's running in my own session). It also works if I run the powershell from the other user's session.
I specifically need a way to gracefully shut down the program as the program has a few important cleanup actions required to keep its database in order. So stop-process or process.kill() will not work.
After lengthy research, it does not seem possible to do this. There is, however, a solution which met at least some of my requirements.
You can create a Windows Scheduled Task which is triggered on session disconnect. This allows you to run a cleanup job as the user, rather than as the administrator, which allows programs to exit gracefully.
It has two major drawbacks....
It is called even if the user just has a minor network interruption (so you have to build a wait() function in the script to sleep for a bit and then check if it is still disconnected - not a clean solution.
It isn't called during a log-off event. For that you need to use a logoff script triggered by GPO.
Hope this helps someone in the future.
I have defined two tasks in VS code (flash, monitor) that uses same COM port.
I would like to automaticaly kill monitor task (terminal), before running flash task.
How can I do this ?
Regards,
Boris Makovecki
Not sure if that's possible, but you might be able to run them both in same terminal using make flash monitor?
The problem statement in short: Is there a way in LSF to pass a signal SIGCONT/SIGTSTP to all processes running within a job?
I have a Perl wrapper script that runs on LSF (Version 9.1.2) and starts a tool (Source not available) on the same LSF machine as the Perl script.
The tool starts 2 processes, one for license management and another for doing the actual work. It also supports an option where sending SIGSTSP/SIGCONT to both processes will release/reacquire the license (which is what I wish to achieve).
Running bkill -s SIGCONT <JOB_ID> only resumes the tool process and not the license process, which is a problem.
I tried to see if I can send the signals to the Perl script's own PGID, but the license process starts its own process group.
Any suggestions to move forward through Perl or LSF options are welcome.
Thanks,
Abhishek
I tried to see if I can send the signals to the Perl script's own PGID, but the license process starts its own process group.
This is likely your problem right here. LSF keeps track of "processes running within the job" by process group. If your job spawns a process that runs within its own process group (say by daemonizing itself) then it essentially is a runaway process out of LSF's control -- it becomes your job's responsibility to manage it.
For reference, see the section on "Detached processes" here.
As for options:
I think the cgroups tracking functionality helps in a lot of these cases, you can ask your admin if LSF_PROCESS_TRACKING and LSF_LINUX_CGROUP_ACCT are set in lsf.conf. If they aren't, then you can ask him to set them and see if that helps for your case (you need to make sure the host you're running on supports cgroups). In 9.1.2 this feature is turned on at installation time, so this option might not actually help you for various reasons (your hosts don't have cgroups enabled for example).
Manage the license process yourself. If you can find out the PID/PGID of the license process from within your perl script, you can install custom signal handlers for SIGCONT/SIGSTP in your script using sigtrap or the like and forward them to the license process yourself when your script receives them through bkill. See here.
I tried to run JConsole to analyze the memory used by a running process, but JConsole doesn't show me processes even though I am absolutely sure that one is running (in addition to that it should show JConsole in the process list as well but it doesn't).
Does anyone have an idea why it doesn't show any processes?
Cheers
at window prompt, run echo %TMP%, it will give you default temp dir. Go to that directory and find directory named hsperfdata_user where user is your login. This is directory to store your process id. Any new process you created such as java application will have a new file named by process id. Jconsole will pick up the process ids from this directory. If you cannot create a file in this directory, that means you need change permission to allow write. Once done that, start a new java application to see if new process id file is in the dir. Once confirmed, start jconsole
I have the same problem. But if I explicitly specify the PID, as in jconsole 1234, jconsole is able to analyze the process.
If you are running jconsole on windows - simply :
Find jconsole.exe
Right click it
Select run as administrator.
In my case, removal of hsperfdata_USERNAME directory (in %TMP% directory) and closing all the JVMs has helped.
This happens when %TMP% value is different for monitored JVM and the monitoring tool (JConsole/JMC/Java Mission Control, maybe even VisualVM).
This may be the standard scenario with Cygwin (at least in my case: Cygwin+Babun)
Easiest solution is to set value of the TMP environment variable to the default value used by Windows, at least in scope of shell launching the JVM.
You have to start jconsole with the same user as the process you want to analyze is started by.
Just ran into this issue
If you are using multiple jdk's by any chance (ex. SDKMAN), then make sure that jconsole is run using the same jdk as the application
8 years later... I had the same problem. I could only see certain processes but couldn't see and monitor any java processes running in a docker container in Linux.
Inspired by the Windows solution by RoyalBigMack:
Solution 1. Run terminal as super user (su command) and run jconsole
Solution 2. Run solution 1 as one command, sudo jconsole
Only the first solution worked for me, and once the jconsole UI popped up- all the hidden processes were now visible.