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From: Robert Watson <rwatson@FreeBSD.org>
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To: Kris Kennaway <kris@FreeBSD.org>
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Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/nfsclient nfs_socket.c
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On Thu, 23 Mar 2006, Kris Kennaway wrote:

>  Fix a bug in the NFS/TCP retransmission path.
>
>  The bug was that earlier, if a request was retransmitted,
>  we would do subsequent retransmits every 10 msecs.
>
>  This can cause data corruption under moderate loads by reordering
>  operations as seen by the client NFS attribute cache, and on the
>  server side when the retransmission occurs after the original request
>  has left the duplicate cache, since the operation will be committed
>  for a second time.
>
>  Further work on retransmission handling is needed (e.g. they are still
>  being done sent too often since they are scaled by HZ, and the size of
>  the dup cache is too small and easily overwhelmed on busy servers).

Wow.  Nice catch.

Robert N M Watson