[Cloud] RE: [IPP] Where is the Cloud Print Manager in the PWG: Cloud Model

[Cloud] RE: [IPP] Where is the Cloud Print Manager in the PWG: Cloud Model

Petrie, Glen glen.petrie at eitc.epson.com
Fri Apr 6 21:47:32 UTC 2012


 

Glen,

 

I'm struggling with a number of statements, I agree the connection
between the user and the cloud is one part of the model, and the other
part is the connection of the cloud to a logical print something or
other (within my system).   Since the model started as an imaging model,
I believe the cloud to print connection should also be usable for a scan
to cloud, with different elements.

 

[gwp] The User connects to either the Cloud Provider's Print Client (a
Cloud Print Client) or an independent Print Client that connects to the
Cloud Provider.  The key is that connection is the User to a Print
Client. 

 

[gwp] Other imaging service would following exactly the same model
without loss of generality; namely,   

 

            User <-----> Print Client          <=> Print Service
<------> Physical Printer

            User <-----> Scan Client           <=> Scan Service
<------> Physical Scanner 

User <-----> Transform Client <=> Transform Service <------> "Physical"
Transforms

 

Users    register

Service register

Users <=> services are associated 

 

As a user and implementer I'm focusing on where the connection to the
cloud originates, and where the connection from the cloud is terminates.

 

[gwp]  As an user you are should have the following concerns

Assumption: The User is a member (registered) with the Cloud Provider -
i.e. has a User account. 

 

1.	Does my (the User's) Cloud Provider support (have
APIs/interfaces) to support an internal or external Print Client
2.	How do I (the User) "install" (register) my (the User) Physical
Printer with the Cloud Provider under my (the User) account
3.	Can/How to set up default Print Settings
4.	Can/How to allow others to use my Physical Printer.

 

Complete actions:

1.	I (the User) have "installed" (registered) my Physical Printer
in my account with my Cloud Provider.

 

Usage:

1.	Using an internal/external Print Client, I (the User) can select
an individual Physical Printer from my of installed Physical Printers
2.	I (the User) can "create" a Print Job for my document using the
capabilities of the selected Physical Printer. 

 

So the User does not know about or care Print Service; the User only
understands the Physical Printer they want to use.

The User certainly does not know how printing is "handled" within the
Cloud and beyond. 

 

The User "just wants to print".

 

[gwp]  As an implementer you are should have the following concerns

First of all: What are you the implementer of?

1.	An application developer invoking a print action from a print
menu selection

	a.	The application will actually invoke a Print Client 

2.	An internal/external Print Client developer capturing Print
Intent and creating a Print Job.
3.	A printer vendor developer wanting to provide Cloud Print
support for my printers.
4.	A Cloud Provider developer wanting to support Printing.

 

In all the implementer cases above you want the APIs for interfacing
with the Print Service associated with a Physical Printer.   And you
don't know, want to know or care "where" the Print Service is; you only
want to know how to access it and that it uses a common (defined,
standardized) set of API for printing.   You don't know, want to know or
care how the Print Service communicates with the Physical Printer; only
that the Print Service can communication with the Physical Printer.  The
Print Service will support the implementer (ultimately the User) by
providing capability information, Print Job submission, reporting
Printing Status, State & Error information and there is likely some
security issues.   Note that Print Service does not know, want to know
or care if specific User has access to the Physical Printer or not; that
is job of the Cloud Provider to support (secure) association.   If a
print vendor provides a fully implement Cloud; then that Cloud is
classified as a Cloud Provider. 

 

So, does the implementer know if there is fan-out or fan-in; that there
is "Print Manager"?  No.

Does implementer know about common or individual queues? No, the Print
Service API provides Print Jobs info (queue info) for the specific
Physical Printer.  (Yes, there may be a system rollup; but that is an
admin operation.)

 

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

In summary: Users see Print Clients

                        Implementers see Print Services 

 

So Print Client <=> Print Services !!!!

 

Also, how does all of this work with federation between Clouds?!?!?! (If
allowed) A Print Service of any Cloud Provider could be "registered"
with the Users' Cloud Provider.  This is a complete transparent
functionality (yes, there a security issues) but the User set their
Print Intent and the Print Client sends the Print Job the User's Cloud
Provider who federates (forwards) the Print Job to the other Cloud
Provider and, so, forth. 

 

So where you have in the last drawing - Vendor M and Vendor N, are those
print services from different print vendors or?

 

Yes

 

 

Larry

 

From: cloud-bounces at pwg.org [mailto:cloud-bounces at pwg.org] On Behalf Of
Petrie, Glen
Sent: Friday, April 06, 2012 10:35 AM
To: Michael Sweet
Cc: ipp at pwg.org; cloud at pwg.org
Subject: [Cloud] RE: [IPP] Where is the Cloud Print Manager in the PWG:
Cloud Model

 

Mike,

 

Thanks for the update.   I was reviewing the diagram again and I had
noted there was no actual print entity "in the cloud"; that is, as an
SAAS in cloud terminology; so adding the Cloud Print Service at least
provides a cloud print SAAS.

 

 

Some more discussion ----------

 

I am still having a problem with the use of a Cloud Print Manager (in
the printer) concept (an the name) in the general context of being a
cloud citizen and with associating a User with an individual Print
Service (Printers).  That is, it is not modeled from User's, use-case or
Cloud Provider developers' point of view.  As currently defined, the
current Cloud Print Manager is an artifact of a particular
implementation (like DocuPrint; maybe even CUPS) for a fan out with a
single controller (Print Servcie?); from a reference model or
architecture point of view it should not matter if there is such an
entity providing this function.  This means your simple diagram reduces
to 

 

 

                         Cloud Print Provider

    Client  <--->  Cloud Print Service <---> Printer

 

With """"""maybe""""" the Printer = [ Cloud Print Manager <--->
Printer(s) ]  as seen from Cloud Print Provider

 

Actually, I see no reason to add the Print qualifier to the Provider;
that is,

 

                             Cloud Provider

    Client  <--->  Cloud Print Service <---> Printer

 

This model states that a Client, as a proxy for the User, can access a
Print Service, of the User's Cloud Provider, to print to a User's
register print device. 

 

This model can be used to represent several different solutions or
implementations:

 

1.	The "Cloud Provider" is Print Cloud (like HP's or Epson's or)

                          Print Cloud Provider

    Client  <--->  Cloud Print Service <---> Printer

	a.	A good and bad model - requires other Cloud Solution to
federate with Print Cloud Provider.   This would be a big development
effort for print vendors. 

 

 

 

2.	Cloud Print Services are integrated into a Cloud Provider like
Google Cloud

                             Cloud Provider

    Client  <--->  Cloud Print Service <---> Printer

	a.	Again, good and bad.   Good for print vendor in that the
Cloud Provider manages Print Service; bad for the same reason.

 

 

 

3.	The Cloud Print Service is a "mini-cloud" or a "plug-in cloud"
(but still in the Cloud) that is callable by a Cloud Provider. 

 

                             Cloud Provider

    Client  <--->    \             \           

                              \            \

  \ Cloud Print Service <---> Printer

Where there is cloud around both Cloud Print and Cloud Print Service

 

	a.	Yes, this looks like model in the current specification
but with some slight differences.

                                                               i.
The Cloud Print Services are in the cloud; thus, they are cloud SAAS 

1.      Yes, the Print Service could be in the physical printer but
virtually linked ("registered") in the Cloud

                                                             ii.      A
printer is associated with a single Cloud Print Service

1.      >From the User's and the Cloud Provider's point-of-view, one
Print Service is associated with one Printer.   The User and Cloud
Provider developers never know about fan-out, fin-in, fan-up, fan-down
or any kind of fan; they know there an associated Print Services for a
specific Printer.  

a.       Internally, an individual "Print Service" can support 2,
700,039 Printers; that is something the print vendor does as part of
their implementation detail.   It will not affect the API's the Cloud
Provider developers uses to print to the printer.  And has nothing to do
with the PWG Cloud Print specification.

2.      >From the User's and the Cloud Provider's point-of-view, one
Print Service (associated with one Printer) has its own queue.   

a.       If a print vendor wants to have individual queues (the "bucket"
of Print Jobs) for each printer or have one giant queue (a big "bucket")
that individual printers pull jobs from, this again, is a print vendor
implementation detail.   And has nothing to do with the PWG Cloud Print
specification.

                                                           iii.
From the Cloud Provider's point-of-view, the above definitions makes all
Cloud Print Service interfaces look the same; that it,

1.      An individual Printer is registered and has an associated a
single Print Service

2.      The Cloud Provider only talks to the Printer's Print Service for
all APIs and actions. 

3.      Print Jobs are submitted to the Print Service for the target
printer (no matter how the queue is implemented)

                                                           iv.
Thus, the goal of the PWG Cloud activity is to define the API's and data
for the Cloud Provider to/from a Cloud Print Service

1.      I know - use IPP

a.       I don't think IPP will be used by everyone.   (Who is using it
now for Cloud?)  What "will be used" is the PWG:PJT, which does not
require IPP to be useful.   PWG:PJT make federation of the Print Jobs
very simple.  In general PWG:PJT is a perfect candidate for cloud print.


 

So the final model is something like

 

                             Cloud Provider                    |-------
a Directory/Registry of Vendor Print Clouds

    Client  <--->    \             \ < -------------------- register
Printers (and its Print Service) to a User 

                              \            \

                                      \ Vendor M Print Cloud
\ Vendor N Print Cloud

                                                Print Service <--->
Printer                                            Print Service <--->
Printer

                                                Print Service <--->
Printer                                            Print Service <--->
Printer

                                                Print Service <--->
Printer                                            Print Service <--->
Printer

                                                Print Service <--->
Printer                                            Print Service <--->
Printer

                                                Print Service <--->
Printer                                            Print Service <--->
Printer

                                                Print Service <--->
Printer                                            Print Service <--->
Printer

 

glen

 

 

 

 

________________________________

From: Michael Sweet [mailto:msweet at apple.com]
<mailto:%5bmailto:msweet at apple.com%5d>  
Sent: Friday, April 06, 2012 9:00 AM
To: Petrie, Glen
Cc: Peter Zehler; Ira Mcdonald; ipp at pwg.org; cloud at pwg.org
Subject: Re: [IPP] Where is the Cloud Print Manager in the PWG: Cloud
Model

 

[Adding cloud at pwg.org since this is a cloud discussion]

 

Glen,

 

In the original BOF-generated functional model, the Cloud Print Manager
is either located in the Printer or attached to the Printer (e.g. in the
local print server).  The Cloud Print Manager manages communications
between the lower-level printer interface and the Cloud Print Provider.

 

Based on our last telecon, we have introduced a Cloud Print Service into
the model which is the service in/under the Cloud Print Provider (which
acts as a System Control Service in the Semantic Model sense) that
manages the jobs/queue in the cloud for the Cloud Print Manager.  The
rough ASCII art diagram in my mind looks like this:

 

 

                   Cloud Print Provider

    Client  <--->  Cloud Print Service  <--->  Cloud Print Manager <--->
Printer(s)

 

Thus, Clients and Cloud Print Managers talk directly to the Cloud Print
Provider and corresponding Cloud Print Service, but never directly to
each other, and only the Cloud Print Manager actually talks directly
with the Printer(s) (physical or logical) it is registering/sharing with
the Cloud Print Provider/Service.

 

There can potentially be multiple logical or physical printers behind
the Cloud Print Manager (think traditional fan-out configurations and
reprographic services) and those printers *may* be addressable using the
IPP/SM output device attributes/elements, but there is only a single
Cloud Print Service per Cloud Print Manager and to the Client it will
appear to be a single "queue" with one or more output devices associated
with it.

 

 

On Apr 6, 2012, at 8:34 AM, "Petrie, Glen" <glen.petrie at eitc.epson.com>
wrote:

 

Ira, Pete,

 

I believe it was stated in the last conference call that the Cloud Print
Manager in the cloud model diagram "is not in the cloud".   Is this
true?  If so, where is it "located"? 

 

Glen

 


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Michael Sweet, Senior Printing System Engineer, PWG Chair

 


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