Sun-Spots Digest, v10n86 [Miscellaneous] - RPC clarification and recommendations

[Basile STARYNKEVITCH]

1) RPC sources are publicly available (send a "help" message to archive-server at rice.edu for details).
2) Every NFS implementation uses RPC above UDP
3) Possibly, NFS implementations have a different RPC lib, but they are supposedly compatible
4) as far as I know RPC libraries are therefore compatible (both protocol and source API levels).
5) RPC also exists above TCP - e.g. for long arguments calls (more than 8kbytes in XDR).
However, note that RPC is a Remote Procedure Call protocol: thsi means
that during a RPC call, the client is waiting for the server's answer.
If you need both machine working at the same time, plain RPC is not for
you. But you could still use the XDR (eXternal Data Representation)
package inside RPC to exchange portable data between different machines
(Sun, Vaxen, PC..) . Better, starting from the RPC/XDR sources, you
could use the xdrstream struff (which handles XDR messages exchanges
above TCP) to implement a (event) message oriented protocol (similar in spirit to X11 protocol..) if this is what you want.

To summarize: if you just want a true RPC paradigm, just use RPC. If you want an event driven message facility, you could use XDR.. You could also look at isis (from ken at cs.cornell.edu (Ken Birman) which adresses similar problems (or ASN1/X409 from OSI?) but I don' know them well. AS far as I know, all these (RPCXDR, ISIS, X409) are above a transport level (such as TCP/IP, sockets, TLI..).


Basile STARYNKEVITCH
Commissariat a l'Energie Atomique
DMT/SERMA
CE. Saclay bat470
91191 GIF/YVETTE CEDEX
France

email: basile at soleil.saclay.cea.fr