[gridrpc-wg] questions about function handles

[Laurent Philippe]

All,

After the last GridRPC meeting in Seoul, we promised to send a new 
proposal for data management in GridRPC and an answer to Hidemoto's 
comments. However, in our discussions we still face a problem on the 
definition of function handles.

There two ways to initialize a function handle.

- first, we can do it with grpc_function_handle_init. In this case, the
  server is explicitly given by the client. As data location is known
  (client, server or data repository), there no problem to bind the data
  to the server. All data management can be done by the client:
  placement, transfers or removal. The location will be given in the data
  management functions.

- second, the function handle could be initialized by
  grpc_function_handle_default. In that case, the GridRPC API document
  says: "This default could be a pre-determined server or it could be a
  server that is dynamically chosen by the resource discovery mechanisms
  of the underlying GridRPC implementation". Does that mean, the function
  handle will contain a server reference in it after
  grpc_function_handle_default call ? Or does that mean, the function
  handle will reference a default discovery (or GridRPC server) while the
  computational server will be chosen during grpc_call ?

  If the function handle contains a reference to a server, then the data
  management can be done in the same way as for
  grpc_function_handle_init. If the function handle does not reference
  the computational server, there no way to know where to place data
  before issuing grpc_call. This is the way function handles are
  implemented in Diet and Netsolve (2.0, any changes ?)
  GridRPC interfaces.

However, we should provide a way to dynamically choose a server...
Any comments ?

    L. Philippe & B. DelFabbro

-- 
Laurent PHILIPPE  http://lifc.univ-fcomte.fr/~philippe
philippe at lifc.univ-fcomte.fr               Laboratoire d'Informatique (LIFC)
tel: (33) 03 81 66 66 54                                     route de Gray
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