Re: [Wrapper-user] Linux daemon question

[Anat H. <an...@en...>]

Hi again,

I didn't get any reply to my last question, so I'm gonna nag again:
Is there any way I can avoid disconnecting the GUI, and still have the 
service functioning on Linux?
Any idea is welcome.

Thanks,
Anat

Anat Halpern wrote:
> Hi Leif,
> It seems you were right - the window is causing this :-(
> I'm attaching 2 log files - one is with a hidden window, and one wo 
> GUI. The first shuts down on logout, while the second continues.
>
> Leif Mortenson wrote:
>> Anat,
>>> The process terminates when I logout, or at least that's how it 
>>> seems. I know the wrapper is not shutting it down, however I thought 
>>> the wrapper is supposed to intercept those signals so that the JVM 
>>> doesn't get them.
>> The Wrapper is capable of catching and handling many signals, but the 
>> JVM
>> is a separate child process of the Wrapper.  If it receives a kill 
>> -9, there is not
>> anything that can be done about it.  At that point, the os is killing 
>> the process
>> at a very low level.  This is true on Windows as well if the user 
>> kills the java
>> process from the task manager.  Processes in both platforms are 
>> protected
>> by user privileges.  But if the user has the privilege to kill the 
>> process, it goes
>> bye bye.
>>> I think the wrapper wouldn't be able to restart the application for 
>>> other reasons as well, but in any case restarting is not the 
>>> solution for this problem.
>> I agree, the reason for the restart not working makes sense in your 
>> case.
>> The question is, who is killing the initial java process?
>>> The original invocation also had a window, but hidden. I am checking 
>>> whether running in service mode, and if so I have the window hidden. 
>>> This is currently easier for me to do than to disentangle the GUI 
>>> code from the application. I plan to separate them, but I hope it 
>>> will not be necessary to do it now. Please let me know if it is...
>> I wonder if the JVM is creating some hooks into the window manager 
>> simply
>> by allocating the resources for a window, even if that window is not 
>> being
>> displayed?
>>
>> Could you create a simple headless application and try this out on your
>> machine?  I would like to find out if this is being caused by hidden 
>> GUI.
>>
> so I'd have to disconnect the GUI, or do you have some other solution 
> in mind?
>> I'll try this out on my home linux machine over the weekend.  I only 
>> have
>> access to remote systems today.
>>
>> Cheers,
>> Leif
>>
> Thanks,
> Anat
>
>
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