Re: [Wrapper-user] How To Pause A Service

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

Ok.  It probably needs some more testing due to the scale of the 
modifications.  But the
new pause/resume feature has been committed to CVS if you want to try it 
out.

The changes were all as I described.

Cheers,
Leif

Leif Mortenson wrote:
> Joos, Heather,
>     I am working on it as we speak.  It will be in the 3.2.1 release.   
> There are some major
> changes to the state engine that are required so it is turning out to be 
> a little more work than
> I had expected.  I think I have everything worked out though.
>
>     The Wrapper will allow 2 modes of operation.  The first will stop 
> the JVM whenever
> the service is paused.  This stoppage will reset the failed invocation 
> count and allow
> restarts from that state even if restarts have been disabled.  A special 
> case.
>     The second mode will keep the JVM running while paused.  But send an 
> event to
> the JVM so it can handle it.   If the JVM crashes for any reason while 
> in this state,
> it will stay down until the service is continued.  When continued, the 
> exit will be
> counted and handled as a regular restart.  If restarts are disabled or 
> the restart count
> exceeds the configured max, the wrapper will stop at that point.
>
>     In either mode, the service can be stopped while paused.  If the JVM 
> is running
> at the time, it can initiate the stop.
>
>     The WrapperListener class itself can not be modified to handle the 
> pause/continue
> events as the addition of such a method would break things for existing 
> users.  I had
> added a new event/listener hierarchy for 3.2.0 that is much more 
> flexible.  This new
> method allows you to handle this as follows:
>
> WrapperManager.addWrapperEventListener( new WrapperEventListener() {
>     public void fired( WrapperEvent event ) {
>        if ( event instanceof WrapperServiceControlEvent ) {
>           WrapperServiceControlEvent scEvent = 
> (WrapperServiceControlEvent)event;
>           switch ( scEvent.getServiceControlCode() ) {
>           case WrapperManager.SERVICE_CONTROL_CODE_PAUSE:
>              myPauseCallback();
>              break;
>           case WrapperManager.SERVICE_CONTROL_CODE_CONTINUE:
>              myContinueCallback();
>              break;
>           }
>        }
>     }
> }, WrapperEventListener.EVENT_FLAG_SERVICE );
>
> You can write the above code in 3.2.0, but those event values will never 
> be received
> as things are implemented in that version.  I haven't compiled the 
> above, so hopefully
> there are no typos. :-)
>
> Cheers,
> Leif
>