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From: G.Eustace@massey.ac.nz (Glen Eustace)
Newsgroups: comp.protocols.nfs
Subject: Re: Avoiding resource waits on unavailable hard mounted fs
Summary: nfsping
Message-ID: <1991Feb17.195507.29832@massey.ac.nz>
Date: 17 Feb 91 19:55:07 GMT
References: <1991Feb14.035507.28805@massey.ac.nz> <978@nih-csl.nih.gov>
Organization: Massey University, Palmerston North, New Zealand
Lines: 25
X-Reader: NETNEWS/PC Version 2.2

My thanks to those responding to this query.  The most sensible
solution seems to be to attempt an RPC operation against the NULL
procedure in one of the nfs daemons on the server in question.

I liked this approach and it ought to work in theory, but I am having
a bit of difficulty in practice.  The program in question, is itself
an rpc daemon.  It is checking another server as part of performing a
service for a PC.  Hence the rpc code in the daemon is being executed
within a routine which is itself an rpc service.

The problem I am experiencing is as follows.  If the target server is
up and running everything works fine.  I query the NULL proc, which
succeeds almost instantly and carry on constructing the reply to the
original request.  However, if the server is not there, the original
request times out and then the target query completes, even though
the timeouts are set so that this should not occur.  It would appear
that the failure of the nested call somehow interfers with the other.

Can anyone shed any light on this behaviour ?

-- 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Glen Eustace, Software Manager, Computer Centre, Massey University,
Palmerston North, New Zealand.        EMail: G.Eustace@massey.ac.nz
Phone: +64 63 69099 x7440, Fax: +64 63 505 607,    Timezone: GMT-12