Newsgroups: comp.os.mach Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mstar!mstar.morningstar.com!bob From: bob@MorningStar.Com (Bob Sutterfield) Subject: Re: Mach RPC Throughput... In-Reply-To: ast@cs.vu.nl's message of 15 Mar 91 20:43:27 GMT Message-ID: Sender: usenet@MorningStar.COM (USENET Administrator) Reply-To: bob@MorningStar.Com (Bob Sutterfield) Organization: Morning Star Technologies References: <9332@star.cs.vu.nl> Distribution: comp Date: Mon, 18 Mar 91 18:01:53 GMT Lines: 16 In article <9332@star.cs.vu.nl> ast@cs.vu.nl (Andy Tanenbaum) writes: The protocol used [by Amoeba] on the Ethernet ... is not IP ... The loss of performance when going through the TCP/IP server is not so important because usually the TCP connections go over a narrow-band wide-area link anyway, so there is no way to get high-performance no matter what. In essence, we have chosen to optimize the local case, and accepted worse performance when one specifically wishes to speak TCP/IP. What about when the non-"local" case involves RPC with a machine on a different Ethernet in the next room, accessible via a high-bandwidth IP router? IP is useful in environments other than wide area networks. Local distributed computing environments might involve multiple networks connected by routers, rather than bridges or repeaters, and it seems that you're designing in a penalty for Amoeba users whose clusters grow too big for one Ethernet.