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Subject: RE: [wsdm] [UPlat] Spec updates
Hi Heather, I am still not comfortable with the "already" in the definition of addressing. It gives the impression that there is a timeline in which one must first understand the acceptable messages and only then look at the addressing data to find out how to invoke the service. As we agreed on the call, the addressing data can include a link to the WSDL of the service, so a possible sequence would be that one gets the addressing data, from there retrieve the WSDL (or parts of the WSDL) and only then goes back to the addressing data to find the endpoint URL. For this reason, I would like the word "already" struck down. Regards, William > -----Original Message----- > From: Heather Kreger [mailto:kreger@us.ibm.com] > Sent: Thursday, November 06, 2003 10:56 AM > To: Andreas Dharmawan > Cc: wsdm@lists.oasis-open.org > Subject: [wsdm] [UPlat] Spec updates > > > > > > > Andreas, > Please replace section 2.1.5 with: > > 1.1.1 Addressing > 1.1.1.1 What? > > An address or reference is the data structure to refer to a unique Web > service with sufficient information to be able to locate and invoke it > given that the supported messages are already understood. The > reference > must include the ability to locate the description of the > service. In this > context address and reference are used synonymously. > > 1.1.1.2 Why? > > It is necessary for management because we need to be able to refer to > manageability services and manageable services in > relationships, events, > and operation signature in an interoperable manner. > > 1.1.1.3 How? > > WS-Addressing > > > WSDL Service Element - per WSDL WG, William to write up > > > WSDL 1.0 URL - Hommayun > > > > > > Please replace 2.1.14 with > > > 1.1.1 Name Resolution > > 1.1.1.1 What? > Name resolution service - A service which accepts an > identifier (URI) and > returns an address/reference. > ?? Is it also necessary to accept a reference and return the > identifier for > it? ?? > > > > 1.1.1.2 Why? > It is necessary for management because resources and > manageability services > have identifiers (from existing instrumentation and > technologies) and it > will be necessary to be able to get a reference for that resource > identifier so that the manager can interact with a resource > through its > > manageability interface. > > Heather Kreger > STSM, Web Services Lead Architect for SWG Emerging Technologies > Author of "Java and JMX: Building Manageable Systems" > kreger@us.ibm.com > 919-543-3211 (t/l 441) cell:919-496-9572 > > > > "Andreas Dharmawan" <andreas@westbridgetech.com> on > 11/03/2003 07:06:51 PM > > To: <homayoun@hp.com> > cc: <wsdm@lists.oasis-open.org> > Subject: RE: [wsdm][UPlat] Meeting Agenda > > > > > Homayoun: > > I sent you wsdm-uplat.doc this afternoon. I transferred the > aggregated > list > of definitions into the template. > > Here I attached it again. It may be easier to read on the > .doc than email > text. > -----Original Message----- > From: M. Homayoun Pourheidari [mailto:homayoun@hp.com] > Sent: Monday, November 03, 2003 4:00 PM > To: Andreas Dharmawan > Cc: wsdm@lists.oasis-open.org > Subject: Re: [wsdm][UPlat] Meeting Agenda > > > Folks, > > Here are the logistics for the uplat 'extra edition' meeting > tomorrow. > > Topics: > > Uplat Document Template (Homayoun) > Notifications (Igor) > Addressing and Name Resolution (Heather) > Transactions (Andrea) > > Time: > > 11:00 am EST / 8:00 am PST > > > Call In Info: > > Toll Free: 866-639-4730 > Toll: 574-948-0377 > Code: 4475012 > > A proposed document template is attached. > > Regards, > H. > --- > > Andreas Dharmawan wrote: > > Here is an updated list based on what we have discussed till 11/3/03. > I am working with Homayoun will get this into the OASIS template doc. > > In the mean time, you may use this to prepare for tomorrow's meeting. > > Change since last time: > - Added Transaction to Medium priority section above cut line > - Modified Versioning based on input from Bryan and Igor > - Added definitions and description to Security from John DeCarlo > - Added Notification from Igor > > > ----- > High: > ----- > > * Identification: > - Definition(s): > Identification is a way to represent that one element is same or > different than the other without necessarily looking at the > contents or definition of the element. Applied to Web resources > in general, as defined by W3C, a Uniform Resource Identifier > (URI) can be used to represent the identity of a Web resource. > Applied to Web services, every element which Web service > description is composed of (service, interface, endpoint, > location, etc.), is required to be identifiable by a URI. > Such URI must be unique by definition. Identity is not required > to be an addressable location, so a dereferencing mechanism > may be required to actually locate the corresponding resource. > > - Management Need(s): > Manageable resources need to be uniquely identified for > the manager to tell one from the other and also to > consistently refer to. Therefore a standard representation of > a unique identity is required. > > * Versioning: > - Definition(s): > Versions: A sequence of copies of (Functional and Manageability) > Webservices incorporating new modifications. Each version is > identified by the version information, following a certain > specified format signifying the major version number and the > release number, embedded in the targetNamespace of the resource > (no need to invent another mechanism in WS). > > Typically an increment in the major version signifies a > substantial increase in the function of the Webservice or a > partial or total re-implementation. > > Whereas the release number increases each time the Webservice > is changed in any way and re-released. > > Versioning information must also contain change description > that describes what has changed in a revision compared to > the previous one. > > All (functional and manageability) resouces can be versioned > to enable maximum flexibility and to anticipate future uses. > The versionable resources are: interfaces, endpoints, and > services. So a service may contains functional and > manageability endpoints and interfaces. The versions of > functional and manageability endpoints and interfaces may > be different due to partial upgrades. > > - Management Need(s): > 1. Version numbers are useful so that the manager can know > if the manageable Webservice interfaces have changed > (bugs have been fixed or new functions added) since she > obtained her copy. She could also learn whether a bug > report relates to the current version. > 2. A manager of manageable resources must have the ability to > query the available endpoints' revisions along with the > corresponding change descriptions such that the manager > can discern the most appropriate and compatible interface of > a particular manageability function that her management > client can use. > > * Attributes: > - Definition(s): > Schema to describe attributes of a Web service and portType > operations to access and set the attributes. Attributes should be > introspect-able at design time and runtime. Attribute is > synonymous with property. For manageability, a property is a name, > type, value triple that is part of the advertised manageability > interface for a resource. An attribute can be used to represent > configuration values, metrics, identifiers, etc. > > * Metadata: > - Definition(s): > Attribute Metadata - schema that defines how to describe metadata > about attributes, operations, events, or interfaces of a Web > service. This metadata for attributes could include > includes units, > volatility, modifiability. Metadata about operations may include > idempotency, endState. Metadata should be introspect-able > at design > time and runtime. > > Note that metadata applies to more than just attributes. > Operations and events. And interfaces. > > Do we need a definition of metadata? Should it include policies? > WSDL documents? Is it settable? "Data about data". "Definition of > data that provides information about what is being managed." > Don't want to include metadata that is "related" to the data, > just the metadata that is "about" the data. Or Definitional. > > From Dictionary.com: > <data> /me't*-day`t*/, or combinations of /may'-/ or > (Commonwealth) /mee'-/; /-dah`t*/(Or "meta data") Data about > data. In data processing, meta-data is definitional data > that provides information about or documentation of other data > managed within an application or environment. > > For example, meta-data would document data about data > elements or attributes, (name, size, data type, etc) and > data about records or data structures (length, fields, > columns, etc) and data about data (where it is located, how it > is associated, ownership, etc.). Meta-data may include > descriptive information about the context, quality and > condition, or characteristics of the data. > > * Addressing: > - Definition(s): > Addressing is the ability to reference an identified entity > so that it can be accessed. In the case of a web service, > "being accessed" means getting hold of its WSDL description > and any extra information that might be needed to route > messages to the service. > > Addressing is the ability to reference another entity. One > examples of where a reference is required is in a relationship > to refer to the entities that have an association with each other. > Another example is to refer to the Web service where asynchronous > notifications should be sent. In general, the Web service > exposing the manageability interfaces for a resource may need > a reference to the resource. Since not all resources are Web > services, a reference must be defined such that non-Web service > entities can also be referred to. The special case of referring > to a Web service entity should refer to the WSDL for the Web > service such that a manager can choose which Web service endpoint > it wants to send messages. > > - Management Need(s): > Addressing is required to provide references to other entities. > Other entities may include resources, Web services, WSDL > documents, > policy descriptions, as well as other documents and services. > Addressing defines the mechanism used to specify the reference. > Management using Web services requires a standard mechanism for \ > referring to other entities. > > * Notification: > - Definition(s): > Notification is a method of conveying information from a source to > recipients that expressed interest in that information. In terms > of Web services it means delivering an XML message from the source > to addressable recipients. An interest in receiving those messages > must be established by the recipients, or by third > parties on behalf > > of the recipients. When registering interest, address(es) of > recipient(s) must be provided (see Addressing). > > - Management Need(s): > Manageable resources need to convey information to the managers. > In certain cases, it is unreasonable for the manager to explicitly > poll (request) the information, and it has to be sent to the > manager by the resource. For example, a manager may be interested > when a service receives a new message. The resource representing > the service has to notify the manager when it happens (event). > The resource needs to know which managers are interested in which > information and what are the deliverable addresses of the managers > to send the notification message when an event occurs. > > When considering requirements on the platform with regards to > means of notification, it is important to separate capability of > simple message exchange for the purposes of notification from the > complex event processing (CEP). The former may be achievable with > a little effort and the later is a discipline of its own and > usually requires a lot of supporting infrastructure that has > nothing to do with means of notification, per se. To be concrete > simple notification is required to efficiently provide > manageability of resources. CEP can be built on top of simple > notification and may be considered out of scope for now. > > To make simple notification possible the folowing has to happen > 1. recipient has to know how to register interest with the > source of information > 2. source has to know how to deliver information to recipient > 3. recipient needs to know that is it being notified ans also > by which source > > Assuming that both the source and recipient are implemented and > run on Web services platforms with Web services tools. Assume > that both source and recipient want to implement notification > using Web services. Web services tools/platforms are designed > to facilitate easy creation and deployment of a client and a > service type of applications, in which case, traditionally, a > client is an initiator and a service is the responder in the > interactions. To make it possible, service provides a > description how it expects the interaction to happen and client > understands it. The interesting difference is that boh > recipient and the source have to be initiators and responders > to be able to implement the three requirements outlined above. > Therefore both recipient and source need to provide > descriptions how the interactions need to happen. Each side > can only provide descriptions of interactions it will respond > to. The source can provide description of how a recipient > needs to register its interest in available information, and > the recipient can provide description how a sourc can deliver > information to it. Definitely, both sides need to have an > apriori agreement on (and knowledge of) both of the > descriptions to allow the bidirectional interaction to happen. > > The claim is that if the above three requirements are satisfied > by a standard, that is both recipients' and sources' side > descriptions are standardized, it is possible to use existing > Web services tools and platforms to implement recipient and > source as Web services. In that case each Web service is > actually a client and a service to the other one, but both > are aware of ecah other's abilities as a recipient or the > source. > > Such standard would have to define source's side description > with > - how to register an interest in an identifiable > information (e.g. name, QName, URI, etc.) > - how to convey address of a deliverable recipient > (e.g. WS-Addressing, URL, etc.) > - how to verify registration of the interest > - how to cancel registration of the interest > - how a source can notify of the unilateral > cancellation of the interest recipient's side > description with > - how to deliver infromation and identify that > it is a notification > - how to tell what source it came from and possibly > what is the context at the source " > > * Relationship: > - Definition(s): > schema to describe relationships between resource types, > resources, interfaces, and endpoints; including portType > operations to get and modify the current set of relationships > from a participant in the relationship. Static relationships and > relationships between types and interfaces should be > introspect-able at design time and runtime. All relationships > should be introspect-able at runtime. > > - Management Need(s): > - design vs. runtime. > - "Static relationships should be introspect-able at design time." > > ---------------------- > Medium above cut line: > ---------------------- > > * Security: > - Definition(s): > Information/Computer Security. There are many ways to categorize > information security, but the most common today is represented > by the letters C, I, A: Confidentiality, Integrity, and > Authentication. Additional concepts that can be arguably kept > separate are: Access Control, Nonrepudiation, Availability, > and Privacy. > > Confidentiality: Preventing unauthorized entities from accessing > information or resources. > > Integrity: Making sure that when authorized entities access > information, it is either not changed or any changes are > detectable. > > Authentication: Making sure that entities are who/what they > claim to be. > > Access Control: Making sure that entities can only access > services, resources, or information that they are authorized > for. > > Nonrepudiation: Making sure the sender of a message can not deny > having sent the message. > > Availability: Making sure a service or resource can be accessed > by authorized users. While this goes beyond security, security > is expected to address denial of service attacks. > > Privacy: Making sure that information on entities is used only > for the express purposes allowed. > > Primarily the issue with Security is that while the requirement > for Security within manageability is extremely important, it is > not unique to manageability. All the same issues arise with > any other Web Services endpoint. Every manageability endpoint > and many business endpoints will have requirements for > confidentiality, integrity, and authentication, as well as > access control, availability, and privacy (see the definition > of Security). > > Also, there is the issue of location. Security may be > implemented in various ways. For example, there could be a > security filter/proxy in front of every Web Services endpoint > (including the manageability endpoint) that only allows > messages through that are valid, authenticated, authorized, > and have no integrity problems identified. Or all of those > functions could be performed by the endpoint itself. > > Thus, the main concern for Security is that the specification > allow for external Security infrastructure mechanisms that are > composable on top of the manageability expsed via Web Services. > This will require examining other standards like WS-Security > to ensure nothing done in the specification precludes the > composability of Security. > > Another external effort is to work with standards groups > developing interoperable Security infrastructure mechanisms. > It is desirable that these mechanisms provide manageability > exposed via Web Services. > > - Management Need(s): > Resources have to be manageable in a secure way (see definition > of security). Security is composable on top of the manageability > exposed via Web services, similar to securing any other > capability of a resource exposed via a Web service. For example, > access to a manageability operation can be granted to only > clients that present "manager's identity" in a request message. > > Security must be manageable, preferably via Web services. > For example, identity or access assertion can be verified by > issuing a request to a security Web service. > > * Registration/Discovery: > - Definition(s): > Registration is a method of advertising an existence of an element > so that it can be discovered. Discovery is a method of locating an > existing element so that it can be used or operated. Discovery > can be based on a selection criteria or simply a name or identity > of an element. Location is a method of obtaining an address of an > element. > > For example, location may mean translating an identity of an > element into an address of an existing useable element. In the > Web services sense, registration, discovery and location can be > represented by a set of operations and schema which may be > implemented by a Registry. A Web service can register itself or > can be registered by a third party by sending a request to the > Registry. A Web service can be discovered by sending a request > to the Registry. The Registry can return the description of a > Web service with location address included in a description or > it may return the location address directly. > > - Management Need(s): > 1. Manageable resources have to be discoverable by the managers. > 2. Manageable resources exposed via Web services can be > registered, > discovered and located via a Registry. > > * Policy: > - Definition(s): > 1. is a course of action, guiding principle, or procedure > considered expedient, prudent, or advantageous for a given > condition or event. > 2. describes a broad range of service requirements, preferences, > and capabilities. > 3. provides a set of requirements to a manageable resources > in a specific context. > > There are various policies that can be specified to a manageable > resources (Webservice functional and manageability endpoints) via > MUWS such as: authentication, access control, privacy, non- > repudiation, service level agreement, quality of service, > routing, content inspection, auditing, etc. policies. > > - Management Need(s): > MUWS must leverage as much as existing Webservices > specifications and technologies in applying policies to the > manageable resources. MUWS should endorse a list of such > specifications and technologies, and should specify the > compatibility and interoperability requirements (i.e. must meet > WS-I). > > * Transaction: > - Definition(s): > A "unit of work" that consists of multiple actions against a > single resource, the same action applied to multiple resources, > or multiple actions against multiple resources. The "unit of > work" should be executed once and only once, even if due to > transmission failures or other errors, the request may be > received multiple times. > > - Management Need(s): > Grouping actions against resources and assuring their execution/ > failure is very valuable. Activities such as IETF's NetConf > discuss "transactions". The goal is for MUWS to be a superset > of the functionality in NetConf - avoiding the need for multiple > protocols/solutions in implementations. > > Manager may request to perform multiple operations on the > manageable resource and integrity of combined request may need > to be preserved. Also that transactions are part of regular WSs > and implementations of manageability merely makes use of those > existing capabilities of WSs. > > ---- > Low: > ---- > > * Collection: > - Definition(s): > A collection is an entity which acts as a proxy to zero or more > other entities. A manager can send a single request to a > collection where the result is that zero or more members of the > collection are acted upon as specified in the request. The > members of a collection are managed entities in their own right > and have their own management interfaces. The result of a > manager sending a single request to a collection must e the > same as a manager sending a separate message to each of the > selected members of the collection individually. It is not > necessary that the collection actually send separate messages > to each of its members, only that the result to the members > is the same. A collection provides a mechanism to perform the > same action on many managed entities at once, and acts > as one scalability mechanism in a management system. > > - Management Need(s): > As the number of managed resources grows, it becomes more > important for a management system to provide a mechanism to > allow a manager to perform the same action on many resources > at once. For instance, with a collection a manager can query > for the state of all resources in the collection at once > rather than one at a time. Also, it is possible for a > collection to reset the state of metrics for the resources > in the collection using a single request. A collection > provides the ability for a management system to scale much > better than a system not supporting collections. Also, there > are cases where the exact membership of a group is better > known by an entity, such as a collection, that may be closer > to the group than a manager. This allows the manager to defer > to the collection to determine the exact entities to act upon. > > * (Work)Flow: > - Definition(s): > the capability to describe a sequence of web services > interactions, where each interaction is fully or partially > determined by the sequence description and the result of > previous interactions in that sequence. > > * Negotiation: > - Definition(s): > Negotiation is the act or process of arranging for or bringing > about through conference, discussion, and compromise. For Web > services, negotiation refers to the process of coming to agreement > on the advertised aspects of a service (e.g., quality of service). > > - Management Need(s): > Negotiation of QoS for a manageability interface seems far off > in the distance from the current work of this group. > > * Relationship Service: > - Definition(s): > A relationship repository or registry which may be responsible > for creating, inventorying, tracking, and validating > relationships. This service is not a participant in the > relationships. If relationships are rule based, then it would > also be responsible for altering relationship members based on > the rules. This would include portType operations for querying, > adding, finding, and validating relationships. This service > would build on the Relationships schema above. > > * Logging: > - Definition(s): > Logging is the action in which message producers generate log > artifacts, i.e., atomic expressions of diagnostic information, > that may or may not be used at a later time by other, > independent, message consumers. Secure logging is required for > audit trails needed to fulfill judiciary and organizational > policy requirements, to reconcile security related > inconsistencies, and to provide for forensic evidence both > after the fact and real-time. > > * Policy Decision Point: > - Definition(s): > A program with a repository that stores and calculates various > (overlapping) policies that can be applied to various > (associated) manageable resources. > > * Policy Enforcement Point: > - Definition(s): > A program that enforces various set of policies on (associated) > various manageable resources. > > ---- > TBD: > ---- > > * Lifecycle: > - Definition(s): > Lifecycle is a set of states that a resource can be in and the > valid transitions between those states. A resource goes > through a set of states and transitions throughout its life. > Lifecycle provides the capability to manage the actual > operational state of a resource, operations to influence a change > in the state of a resources, and events indicating when a > state change has occurred. An application or management tool > uses the lifecycle information for a resource to better manage > that resource. > > For example, valid operations or valid property values of a > resource may be determined through introspection of a resource's > state to aid the application or management tool in doing > those actions only in the state in which those actions are valid. > This is important in autonomic systems where actions taken do not > expect exceptions to be thrown. > > * Name Resolution: > TBD > > > > To unsubscribe from this mailing list (and be removed from > the roster of > the OASIS TC), go to > http://www.oasis-open.org/apps/org/workgroup/wsdm/members/leav > e_workgroup.php > . > > > > > -- > M. Homayoun Pourheidari > Web Services Management Operation > HP OpenView Division > 408.447.5012homayoun@hp.com > > > > To unsubscribe from this mailing list (and be removed from > the roster of > the OASIS TC), go to > http://www.oasis-open.org/apps/org/workgroup/wsdm/members/leav > e_workgroup.php > . >
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