Hi everybody,
First of all, it's the fourth time I am asking for your opinion on this list, but until now no one replied. I don't know why this happens, since all my previous problems were related to simple OJB usage scenarios that failed to work in my case (just as an idea, we had to do some 'workarounds' to avoid these really annoying problems, so they were never considered fixed).
I thought some of you have already experienced those problems. Maybe the problem was the fact that I am using OJB's JDO API (the plugin to JDORI). Who knows... The fact is that I found this particular API incredibly immature. I definitely don't recommend it to anybody. In my case, it is for sure the first and last time when I am using OJB's JDO API. I cannot say anything about PB API, but JDO API is a nightmare.
But anyway, I am sharing my problems again, maybe this time I will get lucky. So, as I said, I am using JDO API for developing a web application that needs multithreading support. My question is: what is the recommended approach for having multithreaded persistence managers?
We've already tried 2 approaches and both of them fail misserably:
1. we tried to get one persistence manager (for all clients) from the persistencemanagerfactory and set it to multithreaded (i.e., setMultithreaded(true)), but during concurrent access (i.e., multiple browser accessing same data at the same time), this fails with "transaction not active" or "transaction already started to commit"-like exceptions.
2. we tried to get one persistence manager per thread (i.e., each tread with its own persistence manager --- using ThreadLocal to store each thread's persistence manager). This works better than the first approach, but from time to time, we get "Instance .... not bound to the persistence manager of the query" exceptions. We couldn't create a step-by-step algorithm to reproduce the problem, but it seems that most of the times this exception appears after the appplication server (we use BEA"s WebLogic) switches the thread on which the web app runs (for us, new thread -> new persistence manager -> probably OJB's cache gets mixed up?!).
Any comments are greatly appreciated.
Thanks in advance, George.
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
