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Subject: [OMPI devel] Device failover in dr pml
From: Mouhamed Gueye (mouhamed.gueye_at_[hidden])
Date: 2009-04-15 08:47:30


Hi all,

We are currently working on the dr pml component and specifically on
device failover. The failover mecanism seems to work fine on different
components, but if we want to do it on different modules of the same
component - say 2 Infiniband rails - the code seems to be broken.

Actually, when the first openib module fails, the progress function of
the openib component is deregistered and progress is no longer made on
any openib module. We managed to circumvent this by keeping the progress
function as long as an openib module might be using it and it seems to
work fine.

So I have a few questions :

1. Is there already work in progress to support multi-module failover on
the dr pml ?
2. Do you think this is the correct way to handle multi-module failover ?

Also, the fact that the "dr" component includes many things like
checksuming bothers us a bit (we'd like to lower performance overhead as
far as possible when including device failover). So,

3. Do you plan to fork this component to a "df (device failover) only"
one ? (we would like to, but maybe this is not the right way to go)

That's all for now,
Mouhamed