Global Lambda Integrated Facility

Subject Re: [GLIF controlplane] RE: Network Control Architecture
From Gigi Karmous-Edwards <gigi@xxxxxxxx>
Date Thu, 19 Apr 2007 07:12:39 -0400

Hi Admela,

I agree, there are two phases, 1) check availability from xRM, and 2) If all xRMs give an ack. then go th second phase of commit, 2') if one or more xRM gives a nack, then do not proceed to the phase two commit. In the architecture sent out, the responsibility of coordinating and administering the two phases is in ONE RB per request. Each xRM will rely on the RB to tell them whether to proceed to a commit or not. If they get a commit from an RB, it then becomes the xRM's responsibility to make the reservation and allocation in the actual resources. I think if for example RB-A talks to an xRM in domain "B", then it may be the responsibility of the xRM-B to tell its own RB-B of its interaction with RB-A. Is this in line with your thoughts?

Gigi

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Gigi Karmous-Edwards
Principal Scientist
Advanced Technology Group
http://www.mcnc.org
MCNC RTP, NC, USA
+1 919-248 -4121
gigi@xxxxxxxx
--------------------------------------------



Admela Jukan wrote:

May I post one more comment.

I think the point of confusion may be that there is no distinction between two phases, i.e., "resource reservation" (Gigi's point B) and "resource allocation" (Inder's point).

In Gigi's architecture, it is a process which reserves a resource and this can be implemented in various ways, e.g., Web services, or so that RM for example only has to discover the IP address of the Resource Controller (a device which controls the resource, NOT the resource itself). If a resource controller advertises its corresponding "resource", similar to UCLP, this resource can be reserved, regardless of the domain it belongs. Strictly speaking, this is done in Layer 7, and locally at every advertised NE. Really no need for any RB to know this.

The problem may happen when the "actual path" has to be established (phase 2), i.e., if there is no agreement between two domain's RB's (e.g., due to firewalls or policy, as Inder rightfully states).

I can think of this as the following. You go to Web and book a flight over a (rogue) airline, you pay (phase 1), and (phase 2) go to the airport, but there is neither the airport nor the airline there (not visible to you (due to RB not being aware of your deal!).

In my view, these two phases are somewhat blurred right now.

On Apr 18, 2007, at 11:34 AM, Gigi Karmous-Edwards wrote:

Hi Inder,

Thank you for your comments.

A) We use Grid in terms of the concept of "resource sharing". In terms of the the interfaces that we all will develop together there will be no Grid relevance. The framework only shows functions and tries to specify interfaces to be standardized. Implementations of the resource broker (RB) and resource mangers (xRM) could be completely independent of Grid technology. We are assuming that a network resource manager could be implemented in various ways which may or may not include Grid components. An example of an Domain Network Resource Manager (DNRM) could be based on DRAC, UCPL, or GMPLS, etc

Another reference to Grid came from the name of the GLIF group, "GLIF Control Plane and Grid Middleware" working group. In my personal opinion, we can just call it middleware rather than Grid middleware. To conclude, the interfaces will not have Grid specific attributes but will accommodate Grid applications.

B) I understand your concerns. This topic was discussed at great length, and I do not think we are all on the same page on this topic. The motivation for allowing a resource broker (RB) access to another domain's resource manager (xRM) is due to the transaction problem associated with the coordination of multiple resources. The implementation of the phase commit is currently the responsibility of the resource broker and not the resource managers. Therefore, if a request comes to a RB for multiple resources across multiple domains, the complexity of the transaction problem will greatly increase if each of the domain's RBs had an independent phase commit and then follow that with an overall phase commit for all the resources across all required domains. In contrast if only one RB was responsible for the phase commit for all the requested resources (across all domains) will simplify the transaction problem. Also, it is assumed that an RB's access to a xRM in its domain has no particular advantage that is not reflected in the policy of the resources (which will be advertised by the xRM).



C) Thank you very much for sharing your document; it is very informative.

I am not sure I addressed all your concerns.... look forward to hearing from you.

Gigi

--------------------------------------------

Gigi Karmous-Edwards
Principal Scientist
Advanced Technology Group
http://www.mcnc.org
MCNC RTP, NC, USA
+1 919-248 -4121
gigi@xxxxxxxx
--------------------------------------------



Inder Monga wrote:

Dear Gigi and All,

I was not present at the last GLIF meeting and plan to remedy that going
forward. I apologize for maybe bringing up the same issues again, but
these are my initial reactions in looking at the slides:

A) I am surprised to see such a deep Grid flavor to the interfaces. I do
understand Grids are an important application of the GLIF network,  but
can't GLIF define generic interfaces that can be used by non-grid
applications, management platforms, automated scripts? To choose this
path because OGF as a likely standardization body is not the right
reason. The defined generic interfaces need to fit into the "grid"
resource management model.

B) In examining the multi-domain proposal, it looks like the RB from one domain can request access to resources directly from the specific RM of the next domain without notifying the RB of the other domain? This model does not appeal to me. I am concerned about the case when resources are required across "n"
domains (say),  RBi (where i belongs to N) needs to access and  request
resouces from xRMj where x = Network, Compute, Storage, Instrument and j = 1 .. n, {n <=N} ? In this case, the RB needs to have knowledge of and
have access to (through firewalls) to all those RMs.

In the multi-domain model we have demonstrated (detailed document
attached) that having each domain manager manage the resources within
its own domain makes the best architecture. With that model you have the
advantage of having only ONE multi-domain resource request entry  point
(and corresponding AAA policies).

I look forward to discussions on the mailing list.

Thanks,
Inder


-----Original Message-----
From: owner-tech@xxxxxxx [mailto:owner-tech@xxxxxxx] On Behalf Of  Gigi
Karmous-Edwards
Sent: Tuesday, April 17, 2007 4:18 PM
To: controlplane@xxxxxxx; GLIF-tech
Subject: [GLIF tech] Network Control Architecture

Dear All,

At the last GLIF control plane meeting in Minneapolis (meeting  minutes
will be sent tomorrow to the list) we had several discussions on
interoperability between the different networks. We drew a diagram on
the white board with input from the participants. The outcome was an
action item on me to send out a high level functional diagram on the
framework for interoperability (sorry for the delay). We expanded the
notion of network resource in the control plane working group to include
other resources as well, such as compute, storage, instruments, etc.

Enclosed are three very high level slides discussing the framework  and
the high level functional components included in a "Resource Broker " and a "Network Resource Manager". Several of you in the meeting had
comments on the interfaces we need to standardize. I propose we start
with the "Grid Network Interface"  GNI, first.

We also agreed to work with both the GLIF community and standard bodies
like OGF to develop these interfaces. I look forward to your  comments.

Kind regards,
Gigi

--
--------------------------------------------

Gigi Karmous-Edwards
Principal Scientist
Advanced Technology Group
http://www.mcnc.org
MCNC
RTP, NC, USA
+1 919-248 -4121
gigi@xxxxxxxx
--------------------------------------------