On 10-12-15 3:03 PM, Manik Surtani wrote:

I'm gonna cc infinispan-dev as well, so others can pitch in.

But yeah, good start. I think your dissection of the use cases makes sense, except that I think (a) and (c) are essentially the same; only that in the case of (c) the task ignores any data input.  This would raise the question of why would anybody do this, and what purpose does it solve. :-)  So yeah, we could support it as a part of (a), but I am less than convinced of its value.  

Ok, no problem. We just have to somehow bootstrap EntryStreamProcessorContext with no access to cache for c case.

And as for data locality, perhaps this would work: don't define the necessary keys in the Task, but instead provide these when submitting the task. E.g.,

CacheManager.submitTask(task); // task goes everywhere, and receives an input Iterator of all local entries on each node.
CacheManager.submitTask(task, K...); // task goes to certain nodes that contain some or all of K.  Receives an input Iterator of all local entries on each node.

WDYT?

Yes, I agree except I'd rather not submit task using CacheManager API. I'd rather just obtain DistributedTask through CacheManager and use task#execute. That we we do not overpollute CacheManager API.

CacheManager cm = ...;
DistributedTask task = cm.newDistributedTask(...);
task.execute();
task.execute(K...);

Ok, if we agree on this what else remains to be resolved? What did you have in mind for further discussion?