[jboss-user] [JCA] New message: "Re: Network boundaries in JCA?"
User development,
A new message was posted in the thread "Network boundaries in JCA?":
http://community.jboss.org/message/525640#525640
Author : Vicky Kak
Profile : http://community.jboss.org/people/vickyk
Message:
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ljnelson wrote:
It is for this reason of course that the connection factory (little c, little f) needs to
be both Serializable and Referenceable. All fine and good.
It is referencable since
the CF needs to be bound to JNDI and implements seriablizable so that the remove clients
can get the refernce over wire. The JCA specs explicitity indicates that the CF should
implement Referencable interface.
So the client asks its JNDI implementation to look up my connection
factory. This all takes place, I presume, on the client VM. What I mean to say is that
when the lookup completes, the client will have an instance of my connection factory,
which was serialized over the wire, either at lookup time or at deployment time
(doesn't really matter to me, although I'm curious here too).
It is at the
deployment time that the CF implemeting the Serializable interface gets bound to the JNDI,
and during the usage of the CF by remote client at run time CF would be serialized over
wire.
Question #1: Is this guaranteed to be a network call? Is
ConnectionManager a remote stub? Or does it drag along the entire connection pooling
machinery with it when it crosses the wire?
ConnectionManager#allocateConnection() now brings the flow back into the application
server, which roots around, does some matching algorithms, and finally results in my
ManagedConnectionFactory implementation having its createManagedConnection() method
called.
Yes it is a n/w call. The JCA infrastruture like the pooling implementation does
not passed to the remote client. The remote client should get the proxy of the CF via JNDI
along with the proxy of CM. Check the implemetation of the jdbc RA in Jboss, check this
class
https://anonsvn.jboss.org/repos/jbossas/branches/Branch_4_2/connector/src...
Question #2: Does this call take place on the server, or on the client? If it takes
place on the server, why is ManagedConnection not mandated to be Serializable? Or my user
connection implementation, for that matter? Neither needs to be Serializable, which tells
me that therefore they don't need to cross the wire. And since the user connection
needs to be on the client side, then because it retains a reference to its
ManagedConnection, then that also tells me that the ManagedConnection is on the client
side.
You should get the Connection Proxy and the MCF/MC calls will happen on server.
The Connection implementation should implement the Serializable interface, it does if you
check the jdbc rar implementation in Jboss
https://anonsvn.jboss.org/repos/jbossas/branches/Branch_4_2/connector/src...
https://anonsvn.jboss.org/repos/jbossas/branches/Branch_4_2/connector/src...
Finally the usage of JCA is not intended to be used remotely, it is suppsoed to used by
the jee components so that they get the infrastruture benefit like pooling,tx and
security. In your case your need seems to get conneted to the EIS via JCA for a standalone
java client, you could do it without the JCA tier.
Ideally from the standalone application you should make a SLSB call which would delegate
the calls to the JCA.
In case of jdbc RAR you could use the thin client to connect to the EIS and need not to go
via JCA tier, similar approach should be applicable with other EIS.
Regards,
Vicky
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