The goal of this task seems a bit ill-defined to me. I think it'd be good to select one object type, have one person work through a draft, send it to the list, and then review that as a group to have a template of how to handle the remaining objects. Also, my guess is that we'll generally end up saying that any MPI object may be invalid after any failure, in fact even failures outside the scope of the user's MPI processes. This can be true for objects that are generally thought of being "local" to the MPI rank, such as information contained in an info object. For example, there is nothing preventing an MPI implementation from storing the contents of an info object on a remote node, such that simple key/value queries may not work after this node has failed. In fact you might have cases where all ranks can talk with one another just fine, but one particular rank can't read its info objects. At very large scales, certain objects like groups will have to be stored in a distributed manner, so that a call to inquire group information will have to access memory on a remote node which may have failed. Thus even a "local MPI call" like MPI_GROUP_TRANSLATE_RANKS might suddently start to return errors when it didn't before. -Adam Howard Pritchard wrote:

Hi Folks,

Here's the list of mpi opaque objects and a few additional constructs for consideration of states in the presence of process failures:

communicators - Aourelian, Wesley groups - Rich G. data types - Sayantan RMA windows - Howard files (file handles) - Darius B. info object - Darius error handler - Darius message obj. - David S. request - Manjo status - Manjo op - Darius port (mpi-2 dynamic) - David S. user buffers attached to MPI for bsends - Sayantan

Need to define lifecycle of the object in the case of no process failures, and in the case when one or more process failures occur while the object exists.

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