Second transaction in the background in an EJB3 application?

Question

Hi!
Is there any way (preferrably with container-managed persistence, but even manually) to implement 2 transactions in EJB3 that fullfil the following criteria:
a)
pseudo-code:
T1 {
doSomething1
start T2 in background
doSomething2
commit
T2 {
doSomething
commit
b)
conditions: T2 "depends" on T1 in the sense that
1. T2 starts during T1
2. if T1 is rolled back ==> T2 must be rolled back, too
(==> this implies: T2 ends after T1 OR T2 waits for T1 to finish before committing)
3. if T2 is rolled back ==> doesn't cause T1 to rollback
c)
graphically: (intended for viewing with a fixed-width font)
("_" = "commit", "." = waiting)
T1
[ ]---> T2
OR
T1
[ ]---> T2
[_]      _The hardest part seems to me to make T2 wait until T1 finishes (in the otherwise unlikely but possible case that T1 finishes first). You can safely presume that the two transactions run on the same JVM, but of course a solution that doesn't rely on this presumption would be even better.
I have tried to find ways for T2 to somehow monitor T1, but on my first half-hearted try I couldn't find anything.
Any ideas?
Thanks,
Agoston
Edited by: 994954 on Mar 19, 2013 11:36 PM

Answer 1

2. if T1 is rolled back ==> T2 must be rolled back, tooI don't think that's possible, the nested transaction is going to be isolated. Otherwise what would be the point of creating it!
The hardest part seems to me to make T2 wait until T1 finishesImplying that T2 is created in a different thread, otherwise T1 would be suspended until T2 finishes in a normal container managed transaction environment. Why thread them when it matters in which order they finish?
I have tried to find ways for T2 to somehow monitor T1, but on my first half-hearted try I couldn't find anythingPerhaps because you've been looking in the context of EJB technology, while you should have been researching 'java concurrency'.