Hi Richard,

Thanks for your comments and some clarifications.

On Mon, Jul 8, 2019 at 12:10 PM Y. Richard Yang <[email protected]> wrote:

> Some quick additional comments. Please see inline.
>
> On Fri, Jul 5, 2019 at 6:02 PM Jensen Zhang <[email protected]>
> wrote:
>
>> Hi ALTOers,
>>
>> After some internal discussions, we are happy to update to WG that we are
>> finalizing the unified properties draft. And below are some key design
>> points:
>>
>> ---
>>
>> 1. Consider UP (Unified Property Map) service as a unified ATLO
>> information resources query mechanism
>>
>> ALTO defines different types of information resources, which have
>> different representation formats. But every information resource can map
>> some kinds of entities to some kinds of properties. e.g., a network map can
>> map ipv4 to pid.
>>
>
> Slight clarification. So far it is not every type of information resource.
> For example, cost may cannot yet, unless we introduce flow/connection, but
> we may say some for now.
>
>
Agree. We will clarify it is extensible. The future document can define new
mappings for existing ALTO information resources.


>
>
>> UP provides a query mechanism to allow clients to get different ALTO
>> information resources in the unified representation format.
>>
>>
> We should clarify that UP provides 3 functions, as we did in the quad
> chart: export, extend, and define. The preceding may give others an
> impression that it limits us to only the first.
>
>
It will be clarified in the document.


> 2. Each UP resource declares a set of (resource_i, DT) -> { (resource_ok,
>> Pk) } mappings
>>
>>
> Can we use r_i, d_i -> r_o, p_o?
>
>
>> Here, resource_ok MUST be either resource_i or this (the current UP
>> resource itself).
>>
>> - When resource_ok == resource_i, the mapping means the client can query
>> the property mapping DT -> Pk defined by resource_i. e.g., "ipv4" -> "pid"
>> defined by "networkmap-1".
>> - When resource_ok == this, the mapping means the client can query
>> entities in the entity domain resource_i.DT, and UP will return the
>> property P defined in its own backend database.
>>
>> The semantics of entity domain resource_i.DT MUST be defined in the IANA
>> registry of resource type of resource_i
>> The semantics of mapping DT -> Pk MUST be defined in the IANA registry of
>> resource type of resource_ok.
>>
>> 2.1. Use DT -> { (resource_ok, Pk) } as a shortcut of the aggregation
>>
>> A UP resource can declare "ipv4" -> { ("net1", "pid"), ("net2", "pid") }.
>> It is equivalent to the outer join of ("net1", "ipv4") -> ("net1", "pid")
>> and ("net2", "ipv4") -> ("net2", "pid"). In this UP, "ipv4" indicates the
>> union of entity domain "net1.ipv4" and "net2.ipv4".
>>
>>
> I do not know what the outer join is. A simple rule is a kind of
> *inheritance* rule:
>
> d_i -> (ro1, po1), (ro2, po2), ...,
>
> <=>
>
> (ro1, d_i) -> (ro1, po1);
> (ro2, d_i) -> (ro2, po2),
> ...
>
> In words, the result is to use the output resource.
>
> Thanks for your clarification. *inheritance* may be a better
clarification. the (ro1, po1) of d_i:e_i (an entity in d_i) inherits (ro1,
po1) of ro1.d_i:e_i (the entity in (ro1, d_i) with the same id).


>
>
>> 3. The client sends the UP query based on the declaration
>>
>>
> It helps that we make clear the declare-use consistent design. Hence the
> final format of capability may be:
>
> // design 1
> query-capability:         a list of mapping
> mapping:                    domain -> properties
>
> properties:                  a list of properties
> property:                     resource-prop | this-prop
> resource-prop:           r_o.p_o    // (r_o, p_o)
> this-prop:                   .p_o         // (this, p_o)
>
> domain:                     resource-domain | generic-domain
> resource-domain:     r_i.d_i
> generic-domain:       d_i
>
> Semantics:
> - resource-domain (r_i, d_i) -> properties
>   is equivalent to (r_i, d_i) -> each property in properties
>
> - generic-domain -> properties
>   use the inheritance rule above
>
> Consistency requirements:
> Export consistency, which applies to
>        an individual-mapping (r_i, d_i) -> (r_o, p_o), where r_i == r_o !=
> this
>      1.1 Capability announcement consistency:
>             d_i -> p_o must be supported by resource r_i
>      1.2. Content consistency
>             (r_i, d_i) -> (r_o, p_o) lookup result is the same as one uses
> r_i itself.
> Extend consistency, which applies to
>       an individual-mapping (r_i, d_i) -> (r_o, p_o), where r_o == this
>    The domain (r_i, d_i) must be supported by r_i
>
> Thanks for your clarification again. I agree with the requirements above.
The document will include them.

Jensen


> Make sense?
>
> Richard
>
>
>> The client queries a list of entities in resource_i.DT or DT, and a
>> subset of properties { (resource_ok, Pk) }.
>>
>> ---
>>
>> We will finish the document revision in the next two days. In the
>> meantime, your comments and feedback are highly welcomed.
>>
>> Thanks,
>> Jensen
>>
>
>
> --
> --
>  =====================================
> | Y. Richard Yang <[email protected]>   |
> | Professor of Computer Science       |
> | http://www.cs.yale.edu/~yry/        |
>  =====================================
>
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