Re: [Wrapper-user] How to properly handle WRAPPER_CTRL_TERM_EVENT?

[Leif M. <lei...@ta...>]

David,
The controlEvent method gives you a chance to either handle or ignore
the signal within the JVM process.  This is a very old API and the
problem with it is that the Wrapper process may also receive a TERM
signal.  If that happens, the Wrapper will proceed to initiate the
shutdown process regardless of what this method does.   For this
reason, this method is more useful as a reporting method.

To prevent your application from responding to TERM signals, you will
want to use the wrapper.ignore_signals property
http://wrapper.tanukisoftware.com/doc/english/prop-ignore-signals.html

On UNIX, the recommended way of doing this is to set the
IGNORE_SIGNALS variable at the top of the shell script that comes with
the Wrapper.  Make sure the Wrapper is stopped when this change is
made as it changes the way the script controls the Wrapper.
Please see the above page for more details.

Let me know how this works for you.

Cheers,
Leif

On Tue, May 17, 2011 at 5:16 PM, David Hoffer <dho...@gm...> wrote:
> I have the wrapper installed on Linux as a service and need as close
> to 100% up time as is possible.  The wrapper recently received a
> WRAPPER_CTRL_TERM_EVENT and shut the app and wrapper down.  My
> controlEvent() is like this...as copied from some JSW sample code...
>
> public void controlEvent(int event) {
>
>         try {
>             if (WrapperManager.isControlledByNativeWrapper()) {
>                 // The Wrapper will take care of this event
>             } else {
>                 // We are not being controlled by the Wrapper, so
> handle the event ourselves.
>                 if ((event == WrapperManager.WRAPPER_CTRL_C_EVENT) ||
> (event == WrapperManager.WRAPPER_CTRL_CLOSE_EVENT) || (event ==
> WrapperManager.WRAPPER_CTRL_SHUTDOWN_EVENT)) {
>                     log.warn("We are handling the received event
> ourselves and we are stopping the service");
>                     WrapperManager.stop(0);
>                 }
>             }
>         }
>     }
>
> Now I see that recent javadocs say to use...(unless one knows what
> they are doing)
>
> public void controlEvent( int event )
>  {
>       if ( ( event == WrapperManager.WRAPPER_CTRL_LOGOFF_EVENT )  &&
> WrapperManager.isLaunchedAsService() )
>        {
>            // Ignore
>        }  else   {
>           WrapperManager.stop( 0 );
>        }
>  }
>
> It seems neither of these handle WRAPPER_CTRL_TERM_EVENT in a way that
> provides 100% up time, rather it just shuts things down cleanly.
>
> What is the right way to handle this?  I.e. should I ignore the
> signal?  should I restart after shutdown?  How?
>
> Thanks,
> -Dave