Web-based Imaging Management Services: RE: WIMS> Prototype q

RE: WIMS> Prototype questions

From: Wagner,William (WWagner@NetSilicon.com)
Date: Tue Aug 03 2004 - 19:02:32 EDT

  • Next message: McDonald, Ira: "RE: WIMS> Prototype questions"

    Ira,

    I agree about the confusion, and some of this has been in the spec for a long time. Hopefully we can address it in the conference call tomorrow.

    If I understand you correctly:

    SendReport and SendAlert operations are sent by agent, but each instance deals with but one managed entity (e.g., a printer). The managed entity is identified by the "SoureURI" parameter, which may or may not bear an commonality with the agent. The spec has defined "SourceURI" as the agent so this has been confusing. "TargetURI" in this case has been defined as referring to the manager...but is that correct and of so, why is this reference necessary?

    It would appear that these meanings for source and target URI also apply to RegisterForManagement and UnRegisterForManagement.

    Schedules include actionTargetURI's, which also identify the managed entity (or entities, if a given action is applicable to multiple entities)

    Then what do the SourceURI and TargetURI in GetSchedule identify? Schedules deal with multiple managed entities. Indeed, schedules are applicable to agents not to managed entities. So in this case, does SourceURI refer to the agent? That may be a confusing and subtle distinction.

    By the same reasoning, in SetSchedule, SourceURI is the manager and TargetURI is the agent.

    In ExecuteAction, SourceURI is still the Manager but TargetURI must identify managed entity? And it is single valued?

    And I need help on the use of target objects (such as Job Object) and the distinction in reference from WMSManagedObjects (which I apparently mistook as referring to the actual variables being managed ..i.e., MIB Objects)

    Bill Wagner

    -----Original Message-----
    From: McDonald, Ira [mailto:imcdonald@sharplabs.com]
    Sent: Tuesday, August 03, 2004 6:02 PM
    To: Wagner,William; Harry Lewis; 'wims@pwg.org'
    Subject: RE: WIMS> Prototype questions

    Hi Bill,

    Serious confusion here about systems, agents, managed entities
    (such as Printer object, application services/devices), and
    managed objects (such as Job object, contained _within_ managed
    entities).

    Both the spec and Schedule schema are currently wrong.

    ActionTargetURIs is a set of URIs of _legacy_ or WIMS agents
    (that is they identify management agents on systems, not just
    WIMS management agents). The documentation in the Alert schema
    for NotifyTargetURIs (for Subscription) shows examples:

    <xsd:element name="NotifyTargetURIs">
      <!-- OPTIONAL - MAY be multi-valued -->
      <!-- list of legacy or WIMS agent URIs to be monitored -->
      <!-- (sources of all later notifications for this subscription) -->
      <!-- e.g., 'pwg-wims://example.com' (a WIMS agent) -->
      <!-- or 'snmp://example.com:162' (an SNMP trap generator) -->
      <xsd:complexType>
        <xsd:sequence>
          <xsd:element name="NotifyTargetURI" type="xsd:anyURI"
            minOccurs="0" maxOccurs="unbounded"/>
        </xsd:sequence>
      </xsd:complexType>
    </xsd:element>

    And the corresponding NotifySourceURI in Alert schema says:

    <xsd:element name="NotifySourceURI" type="xsd:anyURI"/>
      <!-- REQUIRED - MUST be single-valued -->
      <!-- source legacy or WIMS agent URI for this notification -->
      <!-- see notify-printer-uri - section 5.4.5 [IPP-NOT] -->

    It is the TargetURI element that unambiguously names the
    system to be managed (not just the WIMS proxy intermediary).

    The WIMS proxy forwards a given action to a legacy device
    (in SNMP, or whatever) and retrieves the data to formulate
    a correct SendReport (for GetElements) or SendAlert (for
    admin actions or warnings/errors).

    Whereas, the TargetObjects is _already_ in all Report and
    Alert instances, because it's part of 'PlanAction' which
    is returned in a Report or Alert.

    In the near-term managed devices will ALL be legacy and
    WIMS proxies will always have to convert operations and
    elements accordingly.

    I hope this helps. A good diagram of the URIs and the
    addressed entities would obviously be an improvement
    in the spec.

    Cheers,
    - Ira

    Ira McDonald (Musician / Software Architect)
    Blue Roof Music / High North Inc
    PO Box 221 Grand Marais, MI 49839
    phone: +1-906-494-2434
    email: imcdonald@sharplabs.com

    -----Original Message-----
    From: Wagner,William [mailto:WWagner@NetSilicon.com]
    Sent: Tuesday, August 03, 2004 4:37 PM
    To: McDonald, Ira
    Subject: RE: WIMS> Prototype questions

    Ira,

    Seeing your comment to Harry, note that end of fourth paragraph should refer
    to alert schema rather than event schema.

    Bill Wagner

    -----Original Message-----
    From: Wagner,William
    Sent: Tuesday, August 03, 2004 4:27 PM
    To: McDonald, Ira; Harry Lewis; wims@pwg.org
    Subject: RE: WIMS> Prototype questions

    Ira,

    That was pretty much the gist of the question I ask last Friday. As with
    the schedule actions, there are other places where perhaps the distinction
    between the agent and the managed entity should be made. First, let me seek
    to confirm that we have agreement on the following:

    1. Since we have added the TargetObjects parameter to all schedule actions
    that relate to managed objects (as distinguished from agent actions such as
    UpdateSchedule), it can be assumed that a single schedule may refer to many
    managed objects. Further, since the specific actions identify the managed
    entity, the schedule itself is agent oriented.

    2. We agreed that the parameters "Source URI" and "Target URI" refer to the
    Agent and Manager respectively in operations and actions executed by the
    Agent and that these parameters refer to Manager and Agent respectively in
    operations executed by the Manager. But that the term TargetURI must not be
    interpreted to refer to the managed entity. Rather, the new term
    TargetObject will always refer to the managed entity. (you do not seem to
    agree with this in your answer to Harry)

    3. The SendReport and SendAlert Operations from a given agent may deal with
    multiple manageable entities, and these entities are not identified by the
    Target URI term. Rather, they must be identified by a TargetObject term in
    the Send Report or Send Alert Operation (which is not now included) or e4ach
    report or alert entry must include a TargetObject term. I may just be
    missing it but I do not see this terms in either the report or event
    schemas.

    If indeed, a given SendReport (or SendAlert) conveys the results of the
    atomic action for a single one of the ActionTargetURI values, I think we
    need to add the TargetObjects parameter to this operation. Alternatively, if
    each report or alert entry includes the TargetObject, then a given operation
    can handle multiple managed entities.

    But I think we need to distinguish the agent from the managed entity.

    Bill Wagner

    -----Original Message-----
    From: McDonald, Ira [mailto:imcdonald@sharplabs.com]
    Sent: Tuesday, August 03, 2004 3:31 PM
    To: 'Harry Lewis'; wims@pwg.org
    Subject: RE: WIMS> Prototype questions

    Hi Harry,

    My intent all along (I guess not well-documented) is that a given
    SendReport conveys the results of the atomic action for a single
    one of the ActionTargetURI values (identified by the parameter
    'sourceURI' and also the element ReportSourceURI embedded
    in the Report object instance).

    Note that the Source URI identifies EITHER a WIMS Agent
    (such as the proxy running the Schedule) OR a legacy agent
    (such as the SNMP URI of a legacy printer). That's why the
    source is NOT implicit in the originator of the connection.

    Does that help?

    Cheers,
    - Ira

    PS - A refinement would be to have SendReport send a SET
    of Report object instances (one or more), one for each target.

    Ira McDonald (Musician / Software Architect)
    Blue Roof Music / High North Inc
    PO Box 221 Grand Marais, MI 49839
    phone: +1-906-494-2434
    email: imcdonald@sharplabs.com
    -----Original Message-----
    From: owner-wims@pwg.org [mailto:owner-wims@pwg.org]On Behalf Of Harry Lewis
    Sent: Tuesday, August 03, 2004 1:09 AM
    To: wims@pwg.org
    Subject: WIMS> Prototype questions

    I've run into the following question

    When the schedule specifies more than one ActionTargetURI, how do we
    differentiate (in ReportRequestedElements) which ReportElementAny
    corresponds to which ActionTargetURI?

    ----------------------------------------------
    Harry Lewis
    IBM STSM
    Chairman - IEEE-ISTO Printer Working Group
    http://www.pwg.org
    IBM Printing Systems
    http://www.ibm.com/printers
    303-924-5337
    ----------------------------------------------



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