On Apr 4, 2008, at 1:28 PM, Trond Myklebust wrote:
On Fri, 2008-04-04 at 12:49 -0400, Talpey, Thomas wrote:
I think a second or two is way too short, but I do wonder if it can't
issue the unregisters asynchronously, and in parallel. Then it can
wait for them all, with a timeout maybe on the order of 10 to 15
seconds. A couple of retries while waiting sounds reasonable.
Making the wait interruptible seems dicey. Once the deregistration
is started, it seems like it should always make a best attempt to
complete it. Also, nfsd is usually started as a service, so there's
not likely to be a user.
I'd say that making the RPC call asynchronous, but doing an
interruptible wait on completion is probably the best solution.
Making the process entirely asynchronous can be problematic if you
decide to restart the service due to the potential for reordering
between the unregister/register RPC calls.
Another approach that doesn't address interruptibility, but does
prevent waiting for a timeout if rpcbind isn't listening:
Use TCP instead of UDP to contact the local rpcbind daemon. If
rpcbind isn't listening, the connection is refused immediately, and
the RPC client can tell without waiting for a timeout.
We would have to create a new RPC_CLNT_CREATE_FOO flag that tells the
client to fail an RPC immediately if the connection is refused (kind
of like the old "one shot" flag). This shouldn't be the default
behavior.
--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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