First I don't know if my problem is solvable with boinc.
Persistent data which have to be on each host is documented and getting individual persistent data would be automatically solved if the data would be requested on demand. But this is a minor problem.

To show the problem I will try to explain along an example.
- On startup X workunits will be created, and H hosts will download the units one after another. Number of hosts ist constant and are all available during project time.
- Creating a set of workunits is called a 'round'. The complete Project has to be considered as a training. So we hava basedata distributing to the workunits and a list of weights. For simplicity in all rounds the basedate won't change but the weights will be change in each round.
- computing the piecewise basedata is very expensive
The idea is to produce local caches.
But to benefit from those caches I need to get the same workunits in the next round.
It is possible to request preferred workunits. Or better is there a way that a server component selects the right workunit depending on the host

---