Re: Object pooling

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <>
Mon, 20 Sep 2010 22:20:08 -0400
On 20-09-2010 05:09, Robert Klemme wrote:

On 19 Sep., 23:24, Arne Vajh?j<> wrote:

On 19-09-2010 14:13, Tom Anderson wrote:

On Sun, 19 Sep 2010, Robert Klemme wrote:

On 19.09.2010 15:49, Tom Anderson wrote:

I have some heavyweight objects that i would like to try pooling.

To be specific, they're JAX-WS (actually JBossWS) Service (and/or
port) objects. My observations so far are that they take hundreds of
milliseconds to make (if you count instantiation of the service,
instantiation of the port, and extra time taken the first time a
method on the port is called, it seems to be 200-800 ms, depending),
and that the spec doesn't guarantee that they're threadsafe (and as
it happens, i believe that in the JBossWS implementation, neither the
service nor the port is threadsafe).

Since you are using web services which is a pretty much standard way
of accessing business logic I would expect some prepackaged solutions
to be available.

So would i. I haven't come across any, though.

Axis allows you to define the scope of the service to request,
session or application.

The last will reuse. But it does require the service methods
to be individually thread safe. If that does not work for
you, then you need to look for another solution.

That means you either create a bottleneck or have to do the pooling


If the methods are thread safe you can make parallel calls
on the same object.

If not, you could wrap your client code in a JCA connector which then
will be pooled almost automatically by your application container

Man, it's all JCA today!

JCA does not seem to be a good fit for your requirement. You don't
need anything JCA specific. And you can do pools without it.

Why not? Since you are talking to a remote system and _if_ there is
no built in solution in the app server used, then JCA seems like the
exact fit. Basically, talking to remote systems and exchanging
information is exactly what JCA was created for. And you can even
make it transactional. What makes you say it's not a good fit?

JCA is for connecting to systems.

But you don't need it for the standard supported protocols: EJB,
Web Service, JMS etc..

And you don't need any of the special privileges of JCA: using
JNI, starting threads, listening to sockets etc..

And the CCI interface would make the API more cumbersome
not less cumbersome.


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