Spring Transaction management and app server clustering

[liuzh]

a few questions regarding to transaction and clustering:
1. if we use spring transaction management in SLSB, and rely on app server to perform clustering, will the spring tx break? or do we need to take any special care?
2. is it true to say that if we use spring transaction mgt in SLSB, we are using bean managed transaction?
3. (not so spring specific) could we make use of the app server's clustering without using EJB?
4. (a more general question) what are the recommended approaches for using Spring transaction in a clustered environment?

Thanks

[Rod Johnson]

1. No.
2. Yes.
3. Yes and no. HTTP Session clustering works without EJB. Good ORM solutions can handle a distributed cache without EJB, better than EJB CMP. Remote SLSBs and SFSBs offer clustering services unique to EJB for now. However, remote access is often overused.
4. No special considerations. The hard work is done by the database, not in J2EE land.

These issues are discussed in more detail in J2EE without EJB.

[gyArch]

A bean called- 'Account' is in clustered environment deployed/Alive in two deployments A and B in a cluster.
User sends a request Account.deduct(50) twice .
First request lands in deployment A checks the balance and deducts , second in B checks the balance and deducts but an exception is thrown as the balance is now less than 50.

So what is the way to do transaction management with spring to avoid such an exception, clearly Database doesnt help here.

-Gyan