1) The 2.2 standard was an update to the 2.0 standard which predates the 2006 paper you referenced. 2.2 only introduced new functions where there was an urgent need. New features are intended for the forthcoming 3.0.
The forum was unable to reach a consensus, and rather than make a poor specification, they left it undefined.
Now I completely got the "Why?" answer. Thanks.
2) The resource control paragraph is in the context of process creation and my quick 1 minute scan of the paper you referenced indicates that it is discussing reconfiguring communication and does not talk about dynamic processes.
Note that the info argument to the spawn routines, for example, provides a way to communicate with a resource manager; it was an explicit goal of the design of info to provide this way to communication information that is outside of the specification
As you said, That paragraph is in the context of process creating and yes! my question was about runtime reconfiguration of an MPI cluster (whole) based on dynamic application requirements. But I think that would be impossible without having a flexible resource control. When a new node joins a cluster some pre-works must be done to enable that new node act as a member of that cluster (in run time), also, some one must be informed about new resources which just have been added to the cluster by entrance of new node and I think all these preparations need that missing flexible resource manager. Regards, Siavash *