RE:Keep-alive traffic (was iSCSI: more on StatRN)

[Charles Monia <cmonia@NishanSystems.com>]

Hi:

I assume the objection is only to mandatory keep alive.

In high-availabilty scenarios, pinging of some sort goes on all the time to
detect when an otherwise long-dormant node loses connectivity or becomes
brain-dead.

I assume the issue is detection and cleanup of dead iSCSI sessions.  In that
case, why not have the node issue a ping to a dormant session when it has
reason to believe that the session may be blown.

Charles
> -----Original Message-----
> From: Stephen Bailey [mailto:steph@cs.uchicago.edu]
> Sent: Monday, October 30, 2000 3:25 PM
> To: ips@ece.cmu.edu
> Subject: Re: iSCSI: more on StatRN 
> 
> 
> > What probe rate on a waiting response without other confirmation of
> > connection happening would you specify?
> 
> Upon further reflection I'm not sure I analyzed the situation
> correctly.  I know you all think everything through completely before
> you start typing, so you can just stone me right now for not doing the
> same.
> 
> I don't see why free running keep-alives are necessary at all in
> iSCSI.
> 
> Targets only care if the connection is lost when they are returning
> something to the initiator.  Attempting to send anything from target
> to initiator will detect a lost connection, so a keep-alive is not
> necessary.
> 
> Initiators will maintain task timers on outstanding SCSI operations,
> and when a task timer expires, whatever action the initiator performs
> (Abort Task exchange, ping, whatever) will discover the lost
> connection.  Again, no keep-alive is necessary.
> 
> Steph
>