perfsonar development work

[Uros Juvan <>]

Roman Lapacz wrote:
> Uros Juvan wrote:
> > I will be adding perfSONAR services initialization and uninitialization
> > routines, implemented as ServletContextListeners.
> > I am planning to add class
> >
> > org.perfsonar.commons.container.listeners.StartupInitializer
> >
> > for which we have to add the following lines to AXIS's WEB-INF/web.xml:
> >
> > <listener>
> >     
> > <listener-class>org.perfsonar.commons.container.listeners.StartupInitializer</listener-class> 
> >
> > </listener>
> >
> > right after the last <listener> entry.
> >
> > This code has two methods:
> >
> > * contextInitialized:
> >   takes care of initialization of service components:
> >   AuxiliaryComponentManager.getInstance();
> >
> > * contextDestroyed:
> >   takes care of uninitialization of service components
> >   by walking over a Map of components implementing
> >   AuxiliaryThreadedComponent
> >
> > For StartupInitializer to compile, I have to add servlet-api.jar 
> > artifact to
> > libs-download-targets.xml. Thank you Loukik for adding it to our 
> > repository
> > the other day :)
> >
> > I had to add another interface extending AuxiliaryComponent, called
> > AuxiliaryThreadedComponent, which must be implemented by all components
> > running in infinite loop of a spawned thread. AuxiliaryThreadedComponent
> > interface just adds stopThread method, used to terminate thread and
> > effectively a infinite loop.
> > I also changed interface simple Scheduler implements from 
> > AuxiliaryComponent
> > to AuxiliaryThreadedComponent and added method stopThread, which in turn
> > calls stopScheduler method.
> >
> > componentsIterator method was added to AuxiliaryComponentManager 
> > class to
> > support iteration over all the initialized components. This is needed 
> > for
> > contextDestroyed of StartupInitializer class to properly call stopThread
> > method for all components implementing AuxiliaryThreadedComponent.
> >
> >
> > Consequence of these modifications:
> > 1. Start LS Registration scheduler at tomcat startup
> > 2. Bugfix of Tomcat not stopping if LS Registration scheduler started
> >    already
> >
> >
> >
> > Do you think I can commit those changes to SVN? Maciej already agreed,
> > Loukik, Roman, others?
> >   
>
> Looks fine for me. I would also think on this how to automate adding 
> this new listener to web.xml (I would put it somewhere in deploy target).

It looks reasonable to me. I just have to check if Tomcat is shipped 
with classes, which already implement some kind of web.xml handling, 
which I am almost sure it does. I then need to evaluate if it seems 
reasonable potentially adding another Tomcat/Servlet jar file to our 
jar-repository, or does it seem easier to XML parse web.xml by myself 
and insert new <listener> if necessary.

This target may change a bit when Loukik changes the way services are 
installed into Tomcat (multiple services in the same Tomcat instance).

I will commit changes I made so far. If you do not add <listener> 
entries to AXIS's web.xml, then you do not have (un)initializer, i.e. 
everything should work as it did before.

IMPORTANT: You should run libs-generic ant target, when updating your 
copy of perfSONAR code with the perfSONAR's SVN trunk, otherwise you 
might be faced with weird errors about missing classes from 
javax.servlet namespace!

> Roman
>
>
>
> > Regards,
> >   

Regards,

--
Uroš Juvan
Arnes