[acs-wg] Replication discussion material

[Ziu, Peter]

Sachiko, to answer your questions (got carried away last email), see
inserted comments... 

-----Original Message-----
From: owner-acs-wg at ggf.org [mailto:owner-acs-wg at ggf.org] On Behalf Of
Sachiko Wada
Sent: Wednesday, August 10, 2005 12:58 PM
To: acs-wg at ggf.org
Subject: Re: [acs-wg] Replication discussion material

Hi Pete,

I read your document.

Slide 3:
This diagram seems to represent a generic replication concept.
Concerning ACS replication, I assume that an ACS corresponds to a
Replication Element. Am I correct?

-- Not really.  See previous email (it can be applied however).  This
content may be more appropriate for the ogsa-d team to comment on.

If so, GUID is AA ID or AA EPR in ACS term, and ElementValue is
Application Content.
Yes, I agree that ACS should handle change history meta data.

-- As I wrote in the previous mail, I prefer the replication specific
information be maintained by an outer replication service rather than
ACS itself, since those information varies according to the QoS of the
replication service. 

For simplicity sake I agree, however, something will need to coordinate
the control over distribution of ACS content.  Where do you suggest this
is accomplished?  It does not seem natural to do this outside of the ACS
interface.  Perhaps some type of ACS management interface separate from
ACS basic functions?   

Slide 4:
Is this a scenario of replicating multiple AAs controled by a single
policy?

-- It is a structure and methodology ( described in last email) that is
intended to support multiple ACS's replicating multiple AA's, to a level
of granularity as small as ACS-WG desires.

Sachiko

At Wed, 10 Aug 2005 11:18:43 -0400,
Ziu, Peter wrote:
> 
> [1  <text/plain; us-ascii (quoted-printable)>] Sachiko, this is very 
> helpful, as usual, thanks so much for the valuable input.  I have 
> attached a few new slides that I hope might serve to provide the 
> necessary data elements required by a replicative data storage 
> service.  I had hoped to include all of the rules that would apply to 
> maintaining the element values for bi-directional replication (when 
> updating, when creating, when deleting), but they are fairly complex, 
> and I just haven't found adequate time so far.  But, for what it's 
> worth, (see attached).
> 
> Pete.
> 
> -----Original Message-----
> From: owner-acs-wg at ggf.org [mailto:owner-acs-wg at ggf.org] On Behalf Of 
> Sachiko Wada
> Sent: Wednesday, August 10, 2005 11:07 AM
> To: acs-wg at ggf.org
> Subject: [acs-wg] Replication discussion material
> 
> Pete and all,
> 
> Here is the input material for the replication discussion.
> 
> The purpose of this document is to examine the feasibility of 
> constructing a replication service on top of ACS.
> There are the two scenarios:
>  Scenario 1:  One-way synchronization, triggered by modification of 
> the master ACS.
>  Scenario 2:  Two-way synchronization, triggered periodically.
> 
> Conclusion:
>  The replication service can work with ACS if it supports the update 
> event notification as far as considering the two scenarios.
> 
> My impression and proposal:
>  The replicator is supported to be highly sophisticated especially in 
> case of bi-directional synchronization. So I propose that ACS should 
> provide infrastructural functionalities such as notification mechanism

> for the outer replication services instead of supporting replication 
> capability by itself.
>  This time I examined two scenarios to find out that the event 
> mechanism is required to realize them. There may be more replication 
> scenarios which have requirements for ACS spec. For example, the 
> capability to get change histories of an AA should be useful.
> 
> Your comments are very much welcomed.
> 
> Sachiko
> 
> [2 ReplicaElement.ppt <application/vnd.ms-powerpoint (base64)>]
>