Announcement Resources ARC Announcement_Issues Group Name: WG2 Source: Barbara Pareglio, NEC Meeting Date: Agenda Item: Input Contribution

Problem statement Missing a clear description of what is the reason of having “announced resource” Incomplete information for the reader on how to handle these announced resources Not clear how the resources looks like and what to do. © 2013 oneM2M Partners 2

Current state A resource can be announced to one or more remote CESs to inform them of the existence of the original resource Not clearly stated in the TS but the hypothesis is that by means of announcing resources the discovery of a resource is optimized. The announced resource has a limited set of attributes though, and a limited set of child resources from the original resource The announced-resource has a link to the original resource at the resource hosting-CSE, thereby allowing access to the attributes that are not available at the announced-resources © 2013 oneM2M Partners 3

Section 9 Observations: 1.not specified when a resource is eligible to be announced 2.Each annc resource shall be of a new resourceType, the term “corresponding” doesn’t indicate what it should be. The notation of such of such resource is “originalRecourceType”+Annc. (Once a resourceType is assigned it is clear that it belongs only to that specific resource Type.) 9.1.1Resource Announcement The following are the resource specification guidelines for the resource announcement:  Some resource types are announce-able, while others are not. For the announce-able resource type, an additional column shall be specified following the resource template in the section  For an announce-able resource type, suffix "Annc" to the original resource type shall be used to indicate its corresponding announced resource type. For example, resource shall indicate the announced resource type for resource ; shall indicate announced resource type for resource, etc.

Section 9 Child Resource Name of Child Resource Type Multiplicity Description Child Resource See clause where the type of this child resource is described. ; where the is the child resource type in the second column> See clause where the type of this child resource is described. ; where the is the child resource type in the second column> The child resource table for the announce-able resource shall include an additional column titled ' Child Resource', indicating that resource is announce-able. See the section for further details. Table : Child Resources of Observations: 3.An annc resource seems to have children and these children MUST be the announced child resources of the original

Section 9 Attribute Name of Multiplicit y RW/ RO/ WO Description (MP/OP/NP) Provide description of this attribute…to be moved later to a common attribute section. Provide description of this attribute…to be moved later to a common attribute section. Provide description of this attribute.. to be moved later to a central attribute table that also defines the type of the attribute, allowed ranges etc. Provide description of this attribute.... to be moved later to a central attribute table that also defines the type of the attribute, allowed ranges etc. The attributes table for the announce-able resource shall include an additional column titled 'Attribute for ', indicating that resource is announce-able. See the section for further details. Table : Attributes of Observations: 4.An annc resource seems to have a subset of the attributes of the original resource 5.The description only speaks about the presence of the attribute but not the content. The attributes for in the attribute table can have the following set of values:  MP (Mandatory Present): This attributes in the original resource shall be present in the announced resources.  OP (Optional Present): This attributes in the original resource may or may not be present in the announced resources depending on the contents of the announcedAttribute attribute of the original resource.  NP (Not Present): This attribute shall not be present in the announced resource.

Section 9: common attributes Observations: 4.An annc resource shall have the “link”  mandatory for Annc resources 5.Original resource MAY have the announceTo and the announceAttribute  optional for normal resources (cannot be mandatory since announcement is an optional feature)

Example from the TS Child Resource Name of Child Resource Type MultiplicityDescription Child Resource Type [variable] 0..nSee clause Table : Child resources of resource What this means? If the AccessControlPolicy resource is announced, do we also need to announce the subresources? What is the reason for doing that?

Example from the TS Attribute Name of Multiplicity RW/ RO/ WO Description Attribute resourceType (rT)1ROSee clause where this common attribute is described. MP parentID (pID)1ROSee clause where this common attribute is described. MP expirationTime (eT)1RWSee clause where this common attribute is described. MP labels (lBs)0..1RWSee clause where this common attribute is described. MP creationTime (cT)1ROSee clause where this common attribute is described. MP lastModifiedTime (lMT)1ROSee clause where this common attribute is described. MP link1WOSee section where this common attribute is described. This is only for. MP announceTo1RWSee section where this common attribute is described. NP announcedAttribute1RWSee section where this common attribute is described. NP privileges (ps)1RWThe list of privileges defined by this resource. These privileges are applied to resources referencing this resource using the accessControlPolicyID attribute. OP selfPrivileges (sP)1RWDefines the list of privileges for the resource itself. OP Table : Attributes of resource It just indicate that is mandatory, not present or optional but it gives no information about the actual meaning and value

Section 10 The following clauses are defined: – Procedure for AE and CSE to initiate the creation or deletion of the Announced Resource CREATE and UPDATE request for an “Annc resource”, over Mca. Response missing – Procedure for original resource hosting CSE to Announce Resource The hosting CSE CREATing the real Annc resource only acting on announceTo, over Mcc – Procedure for original resource hosting CSE to delete the Announced Resource Hosting CSE DELETing the real Annc resource based on removal of some announceTo, over Mcc – Procedure for AE and CSE to initiate the creation or deletion of the Announced Attribute Originator UPDATE the content announceAttribute for requesting announcing attribute, over Mca. Response missing. – Procedure for original resource hosting CSE to Announce Attribute The hosting CSE CREATing the real Annc attribute only acting on announceAttribute, over Mcc – Procedure for original resource hosting CSE to delete the Announced Attribute Hosting CSE DELETing the real Annc attribute based on removal of some announceAttribute, over Mcc

RETRIEVE &Discovery There is no procedure for reading the announced resource, what is the returned value? What is the result of the discovery procedure for Announced Resource? – There is no description about that – Shall the annc resource be returned of the original resource?

Issues from section 9 Define what is the purpose of announcing a resource clearly, there is only some text in section but it should be said early on the definition of such type of resources. More clarification is needed for: 1.Which resource can be announced, what are the criteria, if any 2.Adding a column on the table for the attribute and resource does not say what the value should be and it creates confusion with the original resource 3.Common attributes needs clarification: Link: contains the URI of the original resource, this is clear announceTo: list of the announced resource. it is confusing the value that can be given in the request and the value that should be provided in the response. announceAttribute: list of announce attributes. Why do we need to announce the resource and also more attributes that are not discoverable directly? Announced resources are not a copy of the original resources and they are not a cache.

Issues on attributes According to only labels attribute is synchronized with the original resource. Clearly the link attribute is needed and it points to the original resource It is not clear what is intended for the other attributes that are not clearly indicated in the same section. The text on child resource is conflicting with the normal announce procedure. If we take the example in slide 8 the Originator could request to announce the child resource without announcing the and if later the latter is announced there might not be a relation between the 2 resources since the Receiver will choose the location of the “annc” resources. This will have a different effect if the Originator has chosen to announce the resource first. Right now “annc” resource cannot contain any “regular” resources as child resource. Is that intentional?

Proposal for the way forward

Proposal Proposal is to define these set of attributes for announce resource: – resourceType: mandatory but not the same of the original resource – parentID: mandatory but it is not the same of the original – expirationTime: mandatory but not the same as the original – accessControlPolicyID: mandatory and the same as the original resource – Labels: mandatory and the same as original – creationTime: mandatory not the same as original – lastModifiedTime: mandatory not the same as original There are 2 type of attributes: – Real attributes with content and not synchronized with the original resource – Synchronized with the original resource: labels and accessControlPolicyID This means that a “annc” resourceType has a very specific set of attributes therefore it would be beneficial to have these attributes described separately in clause and not in the “original resource”

Proposal Do not announce any of the specific resource attribute. Announcing such attributes just complicate the announce procedure for a non specified benefit. Announce child resources independently and not as part of the parent resource. The request over Mca may ask to also announce the child resource, but each resource needs to be created independently over Mcc. Make clear that the attribute “announceTo” may either contains CSE-ID list or the actual location of the new “annc” resource on the request. The attribute however always contains URIs of the actual “annc” resources in the resource representation which will be the only value returned. – Handled the error scenario in case of request with a specific URI that cannot be accepted.

Proposal Describe the procedure in clause clearly as 2 procedures one potential over Mca (if requested by AE) and one over Mcc. These procedures are correlated, so also the handling of response and error need to be very clear. Right now only who knows how the procedure works can understand how the Originator is informed of successful request. (No clear indication of error cases) Make clear if announced resource cannot have any regular resource as child resources or it can.

Proposal Remove procedures on specific attribute ( , , ) Describe how RETRIEVE and discovery works for the announced resource. The proposal is to: – Provide the original as default – Use rc request parameter to specify if the AnncResource or the the link shall be received. There are actual CR already proposed in ARC#10 for fixing some of the issues listed