Edge Rules

Owned by Jane Threefoot
Last updated: Aug 21, 2017
2 min read

Edge Rules Location

The edge rules json files are located in aai-common/aai-core/src/main/resources/dbedgerules.

How to Interpret an Edge Rule

Mentally Constructing an Edge

Read the from/to/direction as a recipe for how to construct the edge.

{

"from": "tenant",
"to": "vserver",
"label": "owns",
"direction": "OUT",
"multiplicity": "One2Many",
"contains-other-v": "${direction}",
"delete-other-v": "NONE",
"SVC-INFRA": "!${direction}",
"prevent-delete": "${direction}"

}

  1. Start by drawing the "from" node.

  2. Draw an edge off this node in the specified. So if it's OUT, point the edge out away from the from node, if it's IN, point it into the node.

  3. Draw the "to" node on the empty end of that edge.



Essentially, "from" and "to" do not imply direction. Think of them as more like "NodeA" and "NodeB".

Quick guide for which is your in node and which is your out node

direction

in node

out node

direction

in node

out node

OUT

to

from

IN

from

to

How to Read Multiplicity

Multiplicity, by itself, has nothing to do with the edge direction or the from/to nodes. Think of it as a property of the edge label. It defines how many IN edges of this label and how many OUT edges of this label are allowed. The format we use is defined by Titan to be In2Out.

Ex: One2Many means on a node, there may be only one IN edge, and many OUT edges.

The from and to node types come in on top of this at the A&AI layer. A&AI's code defines which node types may have those IN and OUT edges of this label.

{

"from": "tenant",
"to": "vserver",
"label": "owns",
"direction": "OUT",
"multiplicity": "One2Many",
"contains-other-v": "${direction}",
"delete-other-v": "NONE",
"SVC-INFRA": "!${direction}",
"prevent-delete": "${direction}"

}

In this example, the vserver gets the IN edge, so it may have only one edge from a tenant. The tenant gets the OUT edge, so it may get many edges to vservers.

Internal Edge Properties

A&AI uses the following edge properties for internal processing.

  • contains-other-v

    • This property defines whether or not the other vertex is contained within another when rendering the resources view

    • This property was previously known as isParent

    • If contains-other-v=OUT, this means that the outVertex contains the inVertex

    • Or in other words, you can read contains-other-v=OUT as "I am an edge, my OUT vertex contains my IN vertex"

  • delete-other-v

    • defines whether or not the other vertex is automatically included in delete processing

    • this property was previously known as hasDelTarget

    • if delete-other-v=IN, this means that when deleting the inVertex also delete the outVertex

  • SVC-INFRA

    • what direction should the traverser continue in when running edge-tag-query

    • if SVC-INFRA=OUT, when on the outVertex traverse to the inVertex and continue

  • prevent-delete

    • defines whether or not this edge can be deleted from a particular direction

    • if prevent-delete=IN, prevent the deletion of the inVertex of the edge, allow the outVertex to be deleted.

    • Or in other words, you can read it as "I am an edge, my IN vertex cannot be deleted"

Quick guide to our direction syntax:

${direction} = same as value of "direction" property

!${direction} = opposite