Re: iSCSI: Canonical Targets

[Stephen Bailey <steph@cs.uchicago.edu>]

Jim,

> I have a question for you (and the list) about a long Text response (as
> might be needed for SendTargets).  Can the Text response come in multiple
> PDUs?  

As I interpret the spec (emphasis on interpret---I don't think the
spec says anything clearly one way or another), yes.

> In particular, can one "key=value" pair span multiple PDUs?

Not as I interpret the spec.

> And if so, does this help address your resources concerns?

No.  The problem I'm talking about is handling an unbounded TOTAL
amount of data returned from a single request.  It doesn't matter
whether it comes in a single PDU or broken into a million, unless you
can offer a finer grain of flow control for the million PDUs than for
the one.  In either case the data returned may a) clog the channel b)
possibly consume resources necessary for other operational purposes.

Again, if we disallow SendTargets (and other interactions with
indeterminate, potentially large uncontrolled flows) in an operational
login, we can allow the transport to provide the flow control.  In an
operational login we don't want to engage transport flow control in
this way because it interferes with other operational communication.

Steph