Hi,
Anatoly Akkerman wrote:
> In the light of Marc's answer, I was wondering, exolab (www.exolab.org)
> has a functioning distributed transaction manager called Tyrex. It
> implements the necessary specs and has been tested (near 1.0 version at
> this point) and should be pluggable into JBoss. Can the future
> implementation of JBossTX be based on Tyrex, instead of reinventing the
> wheel?
IMO, JBoss should be independent of the
transaction service used.
Most of the required independence is
already in place, and only the thread
association in the interceptor chain
still use constructs specific to the
current JTA implementation. But that
shouldn't be hard to change.
On the wire (with the JRMP transport),
the transaction propagation context
is of type java.lang.Object, so any
serializable object can in principle
be used as the transaction propagation
context (TPC).
To support another transaction service
that implements the JTA api, all you
need is to write a MBean for it. An
example MBean is the current MBean
implementation in org.jboss.tm.
The MBean should add three entries to
JNDI:
1) A TransactionManager instance
reference. This makes it possible for
JBoss to look up the TM.
2) A TPC Factory. This converts the
internal transactions to TPCs that can
be transported over the wire.
3) A TPC Importer. This converts TPCs
to Transactions that can be used in
the local VM.
Please note that no UserTransaction
needs to be available. For CMT, the
UT is part of the container who
intercepts UT invocations and end up
calling the TM.
For stand-alone clients, with no
local transaction service, I am
working on a service that delegates
to the server TM, and is also
independent of the transaction service
used in the server.
So once the last calls to the TxManager
specific methods disassociateThread()
and associateThread() have been
replaced with calls to suspend() and
resume(), adding support for other
transaction service implementations
should be simple.
> And if not, then as a temporary solution:
> Would others find it useful if I try integrating Tyrex as an MBean for
> JBoss?
I think that a lot of people would
find that *very* useful, myself
included.
Not just as a temporary solution.
Even if we end up also supporting
other transaction service
implementations: If Tyrex can run
as a MBean under JBoss, no format
conversion is needed when
interoperating with other servers
that use Tyrex, so interoperability
here would be smoother and faster.
If you think you are game for such
a project, I wouldn't mind helping
out as best I can.
Best Regards,
Ole Husgaard.
