ejbLoad "NoSuchEntityException" error

[iaguirre]

We have a session bean accessing to an Entity Bean.
This could be the pseudo-code:
"
Take a collection of entities (with find... method)
for each entity do
if condition A then
update value
else
remove entity

end_for
"

Two parallel executions of the same call take the same entities collection but one of both removes it and the other one generates an error "NoSuchEntityException" for
each entity in the collection.


Jboss should serialize the calls to a method of an EJB, shouldn´t it? It seems that it doesn´t do it.

Has somebody any idea about wich can be the problem.

TIA.

Idoia Aguirre

[jrramon]

Hi,

May this be a bug?

Jose R.

[wolfc]

You say the loop runs parallel (in two Threads possibly).
Let's say the find method returns a collection with 1 entity "MyEntity".
Thread 1: collection = { "MyEntity" };
Thread 2: collection = { "MyEntity" };
Thread 1: remove "MyEntity";
Thread 2: update/remove/query "MyEntity";

Since the entity is not in memory (it's removed), Jboss
will try to load it with ejbLoad. But allas it's also removed from storage, so NoSuchEntityException.

[jrramon]

So, is this a normal behaviour?

I thougth this shouldn´t happen in the execution of the same method of the same EJB.

Jose R.

[wolfc]

It is normal behaviour if you have two Threads/clients calling this bean. You can make your session bean a singleton then the problem would be solved. (At the cost of performance.)

Changing the container configuration in your jboss.xml with the following should do the trick:

<instance-pool>org.jboss.ejb.plugins.SingletonStatelessSessionInstancePool</instance-pool>

<container-pool-conf>
   true
</container-pool-conf>