Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mailrus!ulowell!apollo!mishkin
From: mishkin@apollo.HP.COM (Nathaniel Mishkin)
Newsgroups: comp.protocols.misc
Subject: Re: A comparison of Commercial RPC Systems
Keywords: RPC comparison apollo sun netwise
Message-ID: <44cba282.1d6d5@apollo.HP.COM>
Date: 2 Aug 89 22:00:00 GMT
References: <6569@joshua.athertn.Atherton.COM> <449d9c67.12879@apollo.COM> <118445@sun.Eng.Sun.COM> <44c030ef.1d6d5@apollo.HP.COM> <9574@joshua.athertn.Atherton.COM>
Reply-To: mishkin@apollo.com (Nathaniel Mishkin)
Organization: Apollo Computer, Chelmsford, MA
Lines: 45

In article <9574@joshua.athertn.Atherton.COM> joshua@atherton.com writes:
>    1. If for any reason UDP does not work, a person using Sun's RPC system
>       can use TCP.  (This option is not available to Apollo's RPC users,
>       but is available to Netwise RPC users.)  

Look:  The theory is that the option is simply not necessary.  You pose
the point as if it is a deficiency with that the application isn't obliged
to make the consideration as to what underlying protocol to use.  I just
don't see it that way.  If NCS/RPC (on UDP) is slower -- is intrinsically
slower -- than some other RPC running on TCP, then that's bad for NCS.
I claim that NCS/RPC is not intrinsically slower.  There's no reason
it can't be at least comparable to (if not faster than) TCP/IP in bulk
throughput.  And in short interchanges (a single client making single calls
in turn to a number of servers), it should be noticably better than TCP/IP.

>    2. The fragmentation which Nat is worried about is happening at the IP
>       layer, which is two protocol layers below RPC.  I think it is
>       unfair to blame the RPC implementor for fragmentation which is 
>       happening outside of his control in the protocol stack.  I might 
>       complain to Sun's UDP implementation group about the fragmentation, 
>       but not to their RPC group.

As I thought had been made clear, the problem isn't the UDP implementation --
it's in the nature of UDP and in IP fragmentation.      

>    3. Apollo is much slower than Sun:
>
>           For half K packets Sun TCP is about the same speed as Apollo.
>           For 8K packets Sun TCP is about three times faster than Apollo.
>           For 16K packets Sun TCP is about four times faster than Apollo.

I know you make it clear in your paper, but I want to make it explicit
here:  Your tests were run with a version of NCS that simply did bulk
data throughput in the most naive way conceivable, under the assumption
that the primary use of RPC was not to move tons of data.  I recognize
this to be a very small-minded assumption, but that's life.  In any case,
I've repented for my sins and my observations are that the latest version
of NCS (released on Apollos, in beta on non-Apollos) has increased its
bulk data throughput by 2-3 times.  Performance work continues and I
hope to be able to provide some new numbers soon.

-- 
                    -- Nat Mishkin
                       Apollo Computer Inc., Chelmsford, MA
                       mishkin@apollo.com