[alto] Some considerations about the unified property

[Jensen Zhang <[e-mail]>]

Hi all,

I'd like to resume the discussion about the unified property. From the
discussion [0] between Wendy and Richard, the argument is about: 1) the
hierarchy and inheritance issue. 2) the consistency of the same property
across domains. Here I have some more considerations about this topic.

1. The hierarchical data scheme. The current data scheme is like {Entity ->
{PropertyType -> PropertyValue}}. I'm thinking about if it is possible to
define a more general scheme. Wendy proposed a new approach about unified
cost scheme [1]. And the main argument I remembered is that this approach
is not downward compatible. I do not also want to deprecate the legacy ALTO
services. But why not propose this approach as an extension of the property
map?

2. More general query filter. The unified-prop draft proposes the filtered
property service whose filter is a set of entities. Why not allow the
client to query the property map by setting the constraints of property
values (like constraints in filtered cost map)? Furthermore, we can
introduce an SQL-like feature for the filtered property map service. The
following gives a potential example:

Request:

{
  "entities": [ "flow:1", "flow:2", "flow:3" ],
  "propertyies": [ "ip_src", "ip_dst", "tcp_src" ],
  "constraints": [ "[2] eq 80" ] // Means only selecting the flows whose
tcp_src is equal to 80
}

Welcome to give any comments or propose some new points to discuss.

Best,
Jensen

[0] https://mailarchive.ietf.org/arch/msg/alto/aSg36442jx4-Qtz7mBvfxDsqGSE
[1] https://mailarchive.ietf.org/arch/msg/alto/2l31OYpqzREMe2vBMApZmdhrR80