Re: [Wrapper-user] RE: Disabling JVM ping

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

Clement, Nathan wrote:

>Thanks for your quick reply!  The application was trying to output about 9MB
>worth of log data at the time (something we're obviously going to try and
>reduce).  I have installed the 3.0.1 version of wrapper and have not seen
>the problem since.  I will monitor it closely over the coming days and let
>you know if the problem re-occurs.
>
Good, it sounded like the same problem.  This new version should not have
any more problems with restarts related to large amounts of output.

>My original question still stands - I'm uncomfortable with the idea of the
>application being restarted automatically.  I'd rather our support people
>have to restart the application manually in the rare event of a JVM hang.
>Would it be possible to disable pinging completely as an option for advanced
>users?  Just a suggestion of course.
>
Wow, you want to disable the feature that led me to create the Wrapper in
the first place...  Having just had problems with restarting I can 
understand
your concern.  But in general, the Wrapper is quite good about only 
restarting
the JVM when it is really necessary.  The ability to sleep well at night and
put the old pager in the bottom drawer where it belongs should be viewed
as a good thing :-)

The wrapper.ping.timeout property controls how long the Wrapper will allow
to pass without the JVM responding to a ping.  The problem was inverted
in your case.  The Wrapper process was busy and failed to ping the JVM.
The JVM side of the Wrapper has a feature that will cause it to exit and let
the Wrapper restart it if it ever fails to be pinged for a long period 
of time.
The thinking there was to avoid the JVM turning into a zombie process if
the Wrapper process ever died abnormally.
The fact that this Java side timeout is hard coded at 30 seconds was an
oversight.  It should have been the same as the ping timeout on the
Wrapper side.   A fix is now in CVS and will be in the 3.0.2 release.   
I don't
want to do a release just for this as it is not a critical problem. 
 Unless you
really need this immediately for some reason, I'll wait until there are more
things needing to be released.  You can also do a build from CVS to get
it sooner.

Cheers,
Leif