Messages in this thread | | | Date | Mon, 22 Jan 2001 15:36:38 -0800 | From | "H . J . Lu" <> | Subject | Re: [NFS] [CFT] Improved RPC congestion handling for 2.4.0 (and 2.2.18) |
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On Tue, Jan 23, 2001 at 12:00:29AM +0100, Trond Myklebust wrote: > >>>>> " " == H J Lu <hjl@valinux.com> writes: > > > I got a report which indicates it may not be a good idea, > > especially for UDP. Suppose you have a lousy LAN or NFS UDP > > server for whatever reason, some NFS/UDP packets may get lost > > very easily while a ping request may get through. In that case, > > the rpc ping may slow down the NFS client over UDP > > significantly. > > Hi HJ, > > Could you clarify this? Don't forget that we only send the ping after > a major timeout (usually after 3 or more resends). > > IOW: If the ping gets through, then it'll have cost us 1 RPC request, > which is hardly a major contribution when talking about timescales of > the order of 5 seconds which is what that major timeout will have cost > (Don't forget that RPC timeout values increase geometrically). >
Michael Kriss <kriss@fnal.gov> is having this problem. I think this problem may be very specific to his network setup. I couldn't duplicate his problem. My guess is for his case, every ping sent is a loss of a potential working retry packet. He is using Solaris NFS sever with Linux client. I had an impression that packets from Solaris NFS server was dropped quite often. I don't know what happened.
-- H.J. Lu (hjl@valinux.com) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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