Hello,
Unfortunately, this functionality disappeared in JPPF 3.2, following a complete redesign of the load-balancing in the client. We never even realized it, shame on us

I might be able to put it back in the code and release it in the next maintenance release v3.3.8, but it could take quite some time and then I will also have to port it to the 4.0 branch and to the trunk.
Maybe there are ways to achieve what you need without this functionality. Would you mind providing more details on your debugging and testing requirements in this regard?
For instance, the effect provided with "jppf.local.execution.accumulation.size" could be reproduced with specific load-balancer settings in your configuration.
Concretely, instead of:
jppf.local.execution.accumulation.size = 8
you could set:
jppf.load.balancing.algorithm = manual
jppf.load.balancing.profile = manual
jppf.load.balancing.profile.manual.size = 8
This will result in the JPPFResultCollector getting no more than 8 tasks at a time.
Sincerely,
-Laurent