[jbossws-dev] Eliminate the EndpointRegistry and consolidate the management

[Alessio Soldano]

Hi Jim,
CC-ing ws dev list, as this is possibly of wider interest.


On 05/21/2013 09:29 AM, Jim Ma wrote:
> Hi Alessio,
> 
> As we discussed yesterday, these are my two proposals we might can think
> about and refactor a bit in this  or future release after complete
> jax-rpc removal.
> 
> 1) Eliminate the EndpointRegistry, use EndpointService to get Endpoint info
>    ATM, each deployed endpoint will be created with an EndpointService,
> and each EndpointService will be also registered into serviceContainer.
>    With MSC's getServiceNames() and getService() we can get all the
> deployed endpoint information. ServiceContainer is a registry , so we
> don't need
>    create our own registry to maintain the endpoint map.
>    To resolve the stack/container depends issue ,  we can create similar
> spi api and factory class in integration layer, and return the endpoint
> list to cxf stack .

I've been thinking a bit about this proposal; the way I would possibly
see it implemented is in having a new implementation of the existing
EndpointRegistry SPI interface that internally relies on the container
services (through ServiceContainer). That would be created in the
existing EndpointRegistryService instead of the default impl that's
created now (we'd also need a managed version of it btw, implementing
ManagedEndpointRegistry).
There's no need for a new abstraction interface, given we already have
the EndpointRegistry one (the interface is fine and keeping it would
allow us to avoid touching the stack).
If we did this new impl, we'd not need to explicitly register/unregister
endpoints in the registry in start/stop methods of EndpointService. So
far so good.
The problem is that in change of saving the memory of a map instance,
with the new impl we need to process the whole set of AS services each
time and filter out the WS endpoints ones through name matching, which
is possibly not very good performance-wise. Moreover, we actually lose
control over the actual time an endpoint is registered/unregistered and
is hence available/unavailable for invocation.
So we have pros and cons, I'd say this needs to be properly evaluated...


> 2) Consolidate the jbossws-cxf and cxf management
>    We now have ManagedEndpoint MBean to expose the management info to
> monitor the processTime, requestCount etc. If the cxf management is
> enabled in jboss-webservices.xml,
>    some of the info are duplicate.  We'd think about how to consolidate
> these two kind of management bean. Enable the cxf management by default
> is the way to go ?

The problem I see now is that cxf management is jmx / managed bean
based, and I think I remember the AS might run without the mbean server on.
To be better analysed, also considering that the stats needs to be
available through the Endpoint (they're exposed in the AS managemen, see
org.jboss.as.webservices.dmr.WSEndpointMetrics).



This said, speaking of cleanups, there's actually something I thought
about I'd love to simply and just remembered while looking at your
registry proposal. That's the jbossws SPI resolution mechanism.
Currently we have a double resolution, so e.g. to get Foo we do:

SPIProvider spiProvider = SPIProviderResolver.getInstance().getProvider();
Foo foo = spiProvider.getSPI(Foo.class);

or (when a specific classloader is to be used):

SPIProvider spiProvider =
SPIProviderResolver.getInstance(classLoader).getProvider();
Foo foo = spiProvider.getSPI(Foo.class, classLoader);

both SPIProviderResolver#getInstance and SPIProvider#getSPI internally
rely on the jbossws ServiceLoader, which goes through the usual 3
resolution mechanism (service loader, propfile and sysprop). Moreover,
the default SPIResolver impl in jbws-common (which is what is actually
always used) allows using default values if nothing is found.

I'd like to simplify this; we could remove the SPIProviderResolver
indirection level by having a singleton in SPIProvider returned by a
static getInstance() and resolved once using the jbossws-spi
classloader. No need to try resolve the resolver each time; no need for
such a verbose api.
Something like:

public abstract class SPIProvider
{
   private static SPIProvider me;

   public static SPIProvider getInstance() {
      if (me == null) {
          me = SPIProviderResolver.getInstance().getProvider();
      }
      return me;
   }

   public <T> T getSPI(Class<T> spiType)
   {
      return getSPI(spiType, SecurityActions.getContextClassLoader());
   }

   public abstract <T> T getSPI(Class<T> spiType, ClassLoader loader);
}


and the use it as follows:

Foo foo = SPIProvider.getInstance().getSPI(Foo.class, classLoader);

WDYT?
Cheers
Alessio


-- 
Alessio Soldano
Web Service Lead, JBoss