Dear All : I designed a master-worker framework with boost MPI, in which the master can schedulemultiple tasks (numTaskPerWorkerNode) to each worker and then collects results from workers. if the numTaskPerWorkerNode = 1, it works well. But, if numTaskPerWorkerNode > 1, the master cannot get the results from workers. But, the workers can get the tasks from master. why ? I have used different taskTag to distinguish the tasks, but still does not work. Any help is appreciated. Thanks, Jack July 4 2010 _________________________________________________________________ Hotmail has tools for the New Busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:W...