How does SUNRPC/UDP work?

[Flame Bait]

murthy at thir.cs.cornell.edu (Chet Murthy) writes:
>X-Sun-Spots-Digest: Volume 8, Issue 148, message 4 of 10
>
>I have some questions about SUNRPC (the UDP transport layer) that I can't
>figure out the answers to from the documentation or source.
>
>First, does SUNRPC/UDP allow arbitrary-length messages?  If not, what is
>the maximum-length message?

Sun UDP does not allow arbitrary-length messages.  The documentation
claims that RPC/UDP can handle calls with up to 8K of data.  In fact, it
can support data up to the size of a UDP packet (not surprizing).  This is
not always 8K!  I've used a version of AIX, which supported Sun RPC, but
the UDP packets were only 2K.

>Basically, I'm trying to find out if SUNRPC is suitable for operation in
>an environment where machines can crash pretty often, without degrading
>performance for those machines which are still left running.

This is pretty hard to do with an RPC system.  I suspect that if you make
an RPC call to a machine that is down, it will take awhile for the calling
machine to time out.  You might want to look at broadcast systems, like
Sun's RBT (Reliable Broadcast Toolkit). Talk to Raj Benjaram or Saul Wold
at Sun about getting a copy.  

Joshua Levy                          joshua at atherton.com  home:(415)968-3718
                        {decwrl|sun|hpda}!athertn!joshua  work:(408)734-9822