NETMOD Working Group M. Wang
Internet-Draft Q. Wu
Intended status: Standards Track Huawei
Expires: June 12, 2020 I. Bryskin
Individual
X. Liu
Volta Networks
B. Claise
Cisco
December 10, 2019
A YANG Data model for ECA Policy Management
draft-wwx-netmod-event-yang-06
Abstract
RFC8328 defines a policy-based management framework that allows
definition of a data model to be used to represent high-level,
possibly network-wide policies. Policy discussed in RFC8328 are
classified into imperative policy and declarative policy, Event
Condition Action (ECA) policy is an typical example of imperative
policy. This document defines a YANG data model for the ECA policy
management. The ECA policy YANG provides the ability for the network
management function (within a network element) to control the
configuration and monitor state change and take simple and instant
action on the server when a trigger condition on the system state is
met.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 12, 2020.
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Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 4
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 5
3. Relationship to YANG Push . . . . . . . . . . . . . . . . . . 5
4. Overview of ECA YANG Data Model . . . . . . . . . . . . . . . 6
4.1. ECA Policy Variable and Value . . . . . . . . . . . . . . 6
4.2. ECA Event . . . . . . . . . . . . . . . . . . . . . . . . 7
4.3. ECA Condition . . . . . . . . . . . . . . . . . . . . . . 9
4.4. ECA Action . . . . . . . . . . . . . . . . . . . . . . . 11
5. ECA YANG Model (Tree Structure) . . . . . . . . . . . . . . . 13
6. ECA YANG Module . . . . . . . . . . . . . . . . . . . . . . . 18
7. Security Considerations . . . . . . . . . . . . . . . . . . . 37
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38
9. Acknowledges . . . . . . . . . . . . . . . . . . . . . . . . 38
10. Objectives for existing and possible future extension . . . . 38
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 39
12. Normative References . . . . . . . . . . . . . . . . . . . . 40
Appendix A. ECA Model Usage Example . . . . . . . . . . . . . . 42
Appendix B. Usage Example of Reusing Trigger-Grouping in smarter
filter . . . . . . . . . . . . . . . . . . . . . . . 44
Appendix C. Changes between Revisions . . . . . . . . . . . . . 47
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 48
1. Introduction
Network management consists of using one or multiple device-,
technology-, service specific policies to influence management
behavior within the system and make sure policies are enforced or
executed correctly.
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[RFC8328] defines a policy-based management framework that allow
definition of a data model to be used to represent high-level,
possibly network-wide policies. Policies discussed in [RFC8328] are
classified into imperative policy and declarative policy.
Declarative policy specifies the goals to be achieved but not how to
achieve those goals while imperative policy specifies when Events are
triggered and what actions must be performed on the occurrence of an
event. Event Condition Action (ECA) policy is a typical example of
imperative policy.
Event-driven management of states of managed objects across a wide
range of devices can be used to monitor state changes of managed
objects or resource and automatic trigger of rules in response to
events so as to better service assurance for customers and to provide
rapid autonomic response that can exhibit self-management properties
including self-configuration, self-healing, self-optimization, and
self-protection. Following are some of the use-cases where such ECA
Policy can be used:
o To filter out of objects underneath a requested a subtree, the
subscriber may use YANG Push smart filter to request the network
server to monitor specific network management data objects and
send updates only when the value falls within a certain range.
o To filter out of objects underneath a requested a subtree, the
subscriber may use YANG Push smart filter to request the network
server to monitor specific network management data objects and
send updates only when the value exceeds a certain threshold for
the first time but not again until the threshold is cleared.
o To provide rapid autonomic response that can exhibit self-
management properties, the management system delegate event
response behaviors (e.g., auto-recover from network failure) to
the network device so that the network can react to network change
as quickly as the event is detected. The event response behaviors
delegation can be done using ECA policy,e.g., to preconfigure
protection/ restoration capability on the network device.
o To perform troubleshoot failures (i.e., fault verification and
localization) and provide root cause analysis, the management
system monitoring specific network management data objects may
request the network device to export state information of a set of
managed data objects when the value of monitored data object
exceeds a certain threshold.
o To set up an LSP and reserve resources within the network via
NETCONF protocol operation, Path Computation API RPC model can be
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invoked to calculate a path meeting end-to-end network performance
criteria.
This document defines a ECA Policy management YANG data model. The
ECA Policy YANG provides the ability for the network management
function (within a network element) to control the configurations and
monitor state parameters and take simple and instant action on the
server when a trigger condition on the system state is met.
The data model in this document is designed to be compliant with the
Network Management Datastore Architecture (NMDA) [RFC8342].
2. Conventions used in this document
2.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. In this
document, these words will appear with that interpretation only when
in ALL CAPS. Lower case uses of these words are not to be
interpreted as carrying [RFC2119] significance.
The following terms are defined in [RFC7950] [RFC3460] and are not
redefined here:
o Server
o Client
o Policy variable
o Policy value
o Implicit policy variable
o explicit policy variable
This document uses the following terms:
Event: Something that happens which may be of interest or trigger
the invocation of the rule. A fault, an alarm, a change in
network state, network security threat, hardware malfunction,
buffer untilization crossing a threshold, network connection
setup, an external input to the system, for example.
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Condition: Condition can be seen as a logical test that, if
satisfied or evaluated to be true, cause the action to be carried
out.
Action: Updates or invocations on local managed object attributes.
2.2. Tree Diagrams
Tree diagrams used in this document follow the notation defined in
[RFC8340].
3. Relationship to YANG Push
YANG-push mechanism provides a subscription service for updates from
a datastore. And it supports two types of subscriptions which are
distinguished by how updates are triggered: periodic and on-change.
The on-change push allow receivers to receive updates whenever
changes to target managed objects occur. This document specifies a
mechanism that provides three trigger conditions:
o Existence: When a specific managed object appears,disappear or
object change, the trigger fires, e.g. reserved ports are
configured.
o Boolean: The user can set the type of boolean operator (e.g.
unequal, equal, less, less-or-equal, greater, greater-or-equal,
etc) and preconfigured threshold value (e.g. Pre-configured
threshold). If the value of a managed object meet Boolean
conditions, the trigger fires, e.g., when the boolean operator
type is 'less', the trigger will be fired if the value of managed
object is less than the pre-configured Boolean value.
o Threshold: The user can set the rising threshold,the falling
threshold, the delta rising threshold, the delta falling
threshold. A threshold test regularly compares the value of the
monitored object with the threshold values, e.g., an event is
triggered if the value of the monitored object is greater than or
equal to the rising threshold or an event is triggered if the
difference between the current measurement value and the previous
measurement value is smaller than or equal to the delta falling
threshold.
In these three trigger conditions, existence with type set to object
change is similar to on Push change.
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In addtion, the model defined in this document provides a method for
closed loop network management automation which allows automatic
trigger of rules in response to events so as to better service
assurance for customers and to provide rapid autonomic response that
can exhibit self-management properties including self-configuration,
self-healing, self-optimization, and self-protection. The details of
the usage example is described in Appendix A.
4. Overview of ECA YANG Data Model
A ECA policy rule is read as: when event occurs in a situation where
condition is true, then action is executed. Therefore ECA comprises
three key elements: event, associated conditions, and associated
actions. These three elements should be pushed down and configured
on the server by the client. If the action is rejected by the server
duing ECA policy execution, the action should be rolled back and
cleaned up.
4.1. ECA Policy Variable and Value
ECA policy variable (PV) generically represents information that
changes (or "varies"), and that is set or evaluated by software. ECA
policy Value is used for modeling values and constants used in policy
conditions and actions. In policy, conditions and actions can
abstract information as "policy variables" to be evaluated in logical
expressions, or set by actions, e.g., the Policy Condition has the
semantics "variable matches value" while Policy Action has the
semantics "set variable to value".
In ECA, two type of policy variables are defined, implicit variable
and explicit variable. Explicit variables are bound to exact data
object instance in the model while implicit variables are defined and
evaluated outside of a model. Each ECA policy variable has the
following attributes:
o Name with Globally unique or ECA unique scope ;
o Type either implicit or explicit; The implicit or explicit type
can be further broken down into global or local.
o Value data stored in the policy variable structured according to
the PV type. This structure can be used to keep intermediate
results/meta data during the execution of an ECA policy.
The following operations are allowed with/on a PV:
o initialize (with a constant/enum/identity);
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o set (with contents of another same type PV);
o read (retrieve datastore contents pointed by the specified same
type XPath/sub-tree);
o write (modify configuration data in the datastore with the PV's
content/value);
o insert (PV's content into a same type list);
o iterate (copy into PV one by one same type list elements)
o function calls in a form of F(arg1,arg2,...), where F is an
identity of a function from extendable function library,
arg1,arg2,etc are PVs respectively, the function's input
parameters, with the result returned in result policy variable.
PVs could be used as input/output of an ECA invoked RPC and policy
argument in the func calls. PVs could also be a source of
information sent to the client in notification messages.
PVs could be used in condition expressions
The model structure for the Policy Variable is shown below:
+--rw policy-variables
| +--rw policy-variable* [name]
| +--rw name string
| +--rw type? identityref
| +--rw explict-variable? yang:xpath1.0
| +--rw implict-variable? identityref
| +--rw policy-value? union
4.2. ECA Event
The ECA event are used to keep track of state of changes associated
with one of multiple operational state data objects in the network
device. Typical examples of ECA event include a fault, an alarm, a
change in network state, network security threat, hardware
malfunction, buffer utilization crossing a threshold, network
connection setup, and an external input to the system.
Each ECA Event has the following attributes:
o name, the name of ECA event;
o type, either one time or peridic scheduling;
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o group-id, which can be used to group a set of events that can be
executed together,e.g., deliver a service or provide service
assurance;
o scheduled-time,configuration scheduling - scheduling one time or
periodic.
Nested-event are supported by allowing one event's trigger to
reference other event's definitions using the call-event
configuration. Called events apply their triggers and actions before
returning to the calling event's trigger and resuming evaluation. If
the called event is triggered, then it returns an effective boolean
true value to the calling event. For the calling event, this is
equivalent to a condition statement evaluating to a true value and
evaluation of the event continues.
All events specified in the ECA policy model are continuously
monitored by the server.
The model structure for the ECA Event is shown below:
+--rw event* [name type]
+--rw name string
+--rw type identityref
+--rw event-description? string
+--rw group-id? group-type
+--rw explict-variable* leafref
+--rw clear? boolean
+--rw scheduled-time
| +--rw type? identityref
| +--rw periodic
| | +--rw interval uint32
| | +--rw start? yang:date-and-time
| | +--rw end? yang:date-and-time
| +--rw calendar-time
| +--rw month* string
| +--rw day-of-month* uint8
| +--rw day-of-week* uint8
| +--rw hour* uint8
| +--rw minute* uint8
| +--rw second* uint8
| +--rw start? yang:date-and-time
| +--rw end? yang:date-and-time
+--ro last-event? -> /eca/event/name
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4.3. ECA Condition
Condition can be seen as a logical test that, if satisfied or
evaluated to be true, cause the action to be carried out. In this
model, condition can be specified as logical combinations of the
following three condition expressions:
o Existence: An existence condition monitors and manages the
absence, presence, and change of a data object, for example,
interface status. When a monitored object is specified, the
system reads the value of the monitored object regularly.
* If the existence test type is Absent, the system triggers a
network event and takes the specified action when the monitored
object disappears.
* If the existence test type is Present, the system triggers a
network event and takes the specified action when the monitored
object appears.
* If the existence test type is Changed, the system triggers a
network event and takes the specified action when the value of
the monitored object changes.
o Boolean: A Boolean test compares the value of the monitored object
with the reference value and takes action according to the
comparison result. The comparision hierarchy is logical
hierarchies specified in a form of:
<policy-variable> <relation> <policy-value> or
<policy-variable1> <relation> <policy-variable2>
relation is one of the comparison operations from the set:
==, !=, >, <, >=, <=
o The operation types include unequal, equal, less, lessorequal,
greater, and greaterorequal. For example, if the comparison type
is equal, an event is triggered when the value of the monitored
object equals the reference value. The event will not be
triggered again until the value becomes unequal and comes back to
equal.
o Threshold: A threshold trigger condition regularly compares the
value of the monitored object with the threshold values , with one
of the following mechanisms:
* A rising event is triggered if the value of the monitored
object is greater than or equal to the rising threshold.
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* A falling event is triggered if the value of the monitored
object is smaller than or equal to the falling threshold.
* A rising event is triggered if the difference between the
current measurement value and the previous measurement value is
greater than or equal to the delta rising threshold.
* A falling network event is triggered if the difference between
the current measurement value and the previous measurement
value is smaller than or equal to the delta falling threshold.
* A falling event is triggered if the values of the monitored
object, the rising threshold, and the falling threshold are the
same.
* A falling event is triggered if the delta rising threshold, the
delta falling threshold, and the difference between the current
sampled value and the previous sampled value is the same.
If the value of the monitored object crosses a threshold multiple
times in succession, the managed device triggers an event only for
the first crossing.
In addition, logical operation type can be used to describe complex
logical operations between different condition lists under the same
event, for example, (condition A & condition B) or condition C.
The model structure for the condition is shown below:
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+--rw condition* [name]
| +--rw name string
| +--rw condition-description? string
| +--rw logical-operation-type? identityref
| +--rw call-event? -> ../../name
| +--rw (test)?
| +--:(existences)
| | +--rw existences
| | +--rw type? enumeration
| | +--rw policy-variable? leafref
| +--:(boolean)
| | +--rw boolean
| | +--rw operator? operator
| | +--rw policy-value
| | | +--rw policy-argument
| | | +--rw (argument)?
| | | +--:(explict-variable)
| | | | +--rw explict-variable? leafref
| | | +--:(implict-variable)
| | | | +--rw implict-variable? leafref
| | | +--:(value)
| | | +--rw policy-value? leafref
| | +--rw policy-variable
| | +--rw policy-argument
| | +--rw (argument)?
| | +--:(explict-variable)
| | | +--rw explict-variable? leafref
| | +--:(implict-variable)
| | +--rw implict-variable? leafref
| +--:(threshold)
| +--rw threshold
| +--rw rising-value? leafref
| +--rw rising-policy-variable* leafref
| +--rw falling-value? leafref
| +--rw falling-policy-variable* leafref
| +--rw delta-rising-value? leafref
| +--rw delta-rising-policy-variable* leafref
| +--rw delta-falling-value? leafref
| +--rw delta-falling-policy-variable* leafref
| +--rw startup? enumeration
4.4. ECA Action
The action list consists of updates or invocations on local managed
object attributes and a set of actions are defined as follows, which
will be performed when the corresponding event is triggered:
o sending one time log notification
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o (-re)configuration - modifying a configuration data in the
conventional configuration datastore.
o adding/removing event notify subscription (essentially, the same
action as performed when a client explicitly adds/removes a
subscription)
o executing an RPC defined by a YANG module supported by the server
(the same action as performed when a client interactively calls
the RPC);
o performing operations and function calls on PVs (such as assign,
read, insert, iterate, etc);
Multiple ECA Actions could be triggered by a single ECA event.
Any given ECA Condition or Action may appear in more than one ECAs.
The model structure for the actions is shown below:
+--rw actions
+--rw action* [name]
+--rw name string
+--rw (action-type)?
+--:(set)
| +--rw set
| +--rw policy-variable? leafref
| +--rw value? <anydata>
+--:(logging)
| +--rw logging
| +--rw type? logging-type
| +--rw policy-variable? leafref
+--:(function-call)
| +--rw function-call
| +--rw function-type? identityref
| +--rw policy-argument* [name]
| | +--rw name string
| | +--rw (argument)?
| | +--:(explict-variable)
| | | +--rw explict-variable? leafref
| | +--:(implict-variable)
| | | +--rw implict-variable? leafref
| | +--:(value)
| | +--rw policy-value? leafref
| +--rw result
| +--rw (argument)?
| +--:(explict-variable)
| | +--rw explict-variable? leafref
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| +--:(implict-variable)
| | +--rw implict-variable? leafref
| +--:(value)
| +--rw policy-value? leafref
+--:(rpc-call)
+--rw rpc-call
+--rw name? string
+--rw input
| +--rw policy-argument* [name]
| +--rw name
| | string
| +--rw (argument)?
| +--:(explict-variable)
| | +--rw explict-variable? leafref
| +--:(implict-variable)
| | +--rw implict-variable? leafref
| +--:(value)
| +--rw policy-value? leafref
+--rw output
+--rw policy-argument* [name]
+--rw name
| string
+--rw (argument)?
+--:(explict-variable)
| +--rw explict-variable? leafref
+--:(implict-variable)
| +--rw implict-variable? leafref
+--:(value)
+--rw policy-value? leafref
5. ECA YANG Model (Tree Structure)
The following tree diagrams [RFC8340] provide an overview of the data
model for the "ietf-eca" module.
grouping start-end-grouping
+-- start? yang:date-and-time
+-- end? yang:date-and-time
grouping existences-trigger
+-- existences
+-- type? enumeration
+-- policy-variable?
-> /policy-variables/policy-variable/name
grouping boolean-trigger
+-- boolean
+-- operator? operator
+-- policy-value
| +-- policy-argument
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| +-- (argument)?
| +--:(explict-variable)
| | +-- explict-variable? leafref
| +--:(implict-variable)
| | +-- implict-variable? leafref
| +--:(value)
| +-- policy-value? leafref
+-- policy-variable
+-- policy-argument
+-- (argument)?
+--:(explict-variable)
| +-- explict-variable? leafref
+--:(implict-variable)
+-- implict-variable? leafref
grouping threshold-trigger
+-- threshold
+-- rising-value?
| -> /policy-variables/policy-variable/policy-value
+-- rising-policy-variable*
| -> /policy-variables/policy-variable/name
+-- falling-value?
| -> /policy-variables/policy-variable/policy-value
+-- falling-policy-variable*
| -> /policy-variables/policy-variable/name
+-- delta-rising-value?
| -> /policy-variables/policy-variable/policy-value
+-- delta-rising-policy-variable*
| -> /policy-variables/policy-variable/name
+-- delta-falling-value?
| -> /policy-variables/policy-variable/policy-value
+-- delta-falling-policy-variable*
| -> /policy-variables/policy-variable/name
+-- startup? enumeration
grouping trigger-grouping
+-- (test)?
+--:(existences)
| +-- existences
| +-- type? enumeration
| +-- policy-variable?
| -> /policy-variables/policy-variable/name
+--:(boolean)
| +-- boolean
| +-- operator? operator
| +-- policy-value
| | +-- policy-argument
| | +-- (argument)?
| | +--:(explict-variable)
| | | +-- explict-variable? leafref
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| | +--:(implict-variable)
| | | +-- implict-variable? leafref
| | +--:(value)
| | +-- policy-value? leafref
| +-- policy-variable
| +-- policy-argument
| +-- (argument)?
| +--:(explict-variable)
| | +-- explict-variable? leafref
| +--:(implict-variable)
| +-- implict-variable? leafref
+--:(threshold)
+-- threshold
+-- rising-value? leafref
+-- rising-policy-variable*
| -> /policy-variables/policy-variable/name
+-- falling-value? leafref
+-- falling-policy-variable*
| -> /policy-variables/policy-variable/name
+-- delta-rising-value? leafref
+-- delta-rising-policy-variable*
| -> /policy-variables/policy-variable/name
+-- delta-falling-value? leafref
+-- delta-falling-policy-variable*
| -> /policy-variables/policy-variable/name
+-- startup? enumeration
module: ietf-eca
+--rw policy-variables
| +--rw policy-variable* [name]
| +--rw name string
| +--rw type? identityref
| +--rw explict-variable? yang:xpath1.0
| +--rw implict-variable? identityref
| +--rw policy-value? union
+--rw eca
+--rw event* [name type]
+--rw name string
+--rw type identityref
+--rw event-description? string
+--rw group-id? group-type
+--rw explict-variable* leafref
+--rw clear? boolean
+--rw scheduled-time
| +--rw type? identityref
| +--rw periodic
| | +--rw interval uint32
| | +--rw start? yang:date-and-time
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| | +--rw end? yang:date-and-time
| +--rw calendar-time
| +--rw month* string
| +--rw day-of-month* uint8
| +--rw day-of-week* uint8
| +--rw hour* uint8
| +--rw minute* uint8
| +--rw second* uint8
| +--rw start? yang:date-and-time
| +--rw end? yang:date-and-time
+--ro last-event? -> /eca/event/name
+--ro last-condition? -> /eca/event/condition/name
+--ro last-action?
| -> /eca/event/actions/action/name
+--rw condition* [name]
| +--rw name string
| +--rw condition-description? string
| +--rw logical-operation-type? identityref
| +--rw call-event? -> ../../name
| +--rw (test)?
| +--:(existences)
| | +--rw existences
| | +--rw type? enumeration
| | +--rw policy-variable? leafref
| +--:(boolean)
| | +--rw boolean
| | +--rw operator? operator
| | +--rw policy-value
| | | +--rw policy-argument
| | | +--rw (argument)?
| | | +--:(explict-variable)
| | | | +--rw explict-variable? leafref
| | | +--:(implict-variable)
| | | | +--rw implict-variable? leafref
| | | +--:(value)
| | | +--rw policy-value? leafref
| | +--rw policy-variable
| | +--rw policy-argument
| | +--rw (argument)?
| | +--:(explict-variable)
| | | +--rw explict-variable? leafref
| | +--:(implict-variable)
| | +--rw implict-variable? leafref
| +--:(threshold)
| +--rw threshhold
| +--rw rising-value? leafref
| +--rw rising-policy-variable* leafref
| +--rw falling-value? leafref
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| +--rw falling-policy-variable* leafref
| +--rw delta-rising-value? leafref
| +--rw delta-rising-policy-variable* leafref
| +--rw delta-falling-value? leafref
| +--rw delta-falling-policy-variable* leafref
| +--rw startup?
| enumeration
+--rw actions
+--rw action* [name]
+--rw name string
+--rw (action-type)?
+--:(set)
| +--rw set
| +--rw policy-variable? leafref
| +--rw value? <anydata>
+--:(logging)
| +--rw logging
| +--rw type? logging-type
| +--rw policy-variable? leafref
+--:(function-call)
| +--rw function-call
| +--rw function-type? identityref
| +--rw policy-argument* [name]
| | +--rw name string
| | +--rw (argument)?
| | +--:(explict-variable)
| | | +--rw explict-variable? leafref
| | +--:(implict-variable)
| | | +--rw implict-variable? leafref
| | +--:(value)
| | +--rw policy-value? leafref
| +--rw result
| +--rw (argument)?
| +--:(explict-variable)
| | +--rw explict-variable? leafref
| +--:(implict-variable)
| | +--rw implict-variable? leafref
| +--:(value)
| +--rw policy-value? leafref
+--:(rpc-call)
+--rw rpc-call
+--rw name? string
+--rw input
| +--rw policy-argument* [name]
| +--rw name
| | string
| +--rw (argument)?
| +--:(explict-variable)
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| | +--rw explict-variable? leafref
| +--:(implict-variable)
| | +--rw implict-variable? leafref
| +--:(value)
| +--rw policy-value? leafref
+--rw output
+--rw policy-argument* [name]
+--rw name
| string
+--rw (argument)?
+--:(explict-variable)
| +--rw explict-variable? leafref
+--:(implict-variable)
| +--rw implict-variable? leafref
+--:(value)
+--rw policy-value? leafref
6. ECA YANG Module
<CODE BEGINS> file "ietf-eca@2019-10-28.yang"
module ietf-eca {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-eca";
prefix eca;
import ietf-yang-types {
prefix yang;
}
organization
"IETF NETMOD Working Group";
contact
"Editor: Zitao Wang
<mailto:wangzitao@huawei.com>
Editor: Qin Wu
<mailto:bill.wu@huawei.com>
Editor: Igor Bryskin
<mailto:Igor.Bryskin@huawei.com>
Editor: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>
Editor: Benoit Claise
<mailto:bclaise@cisco.com>";
description
" This module contains YANG specifications for ECA Policy management.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
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Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC xxxx; see the
RFC itself for full legal notices.";
revision 2019-10-28 {
description
"Initial revision.";
reference
"RFC xxxx";
}
identity variable-type {
description
"base variable type";
}
identity global-explict {
base variable-type;
description
"Identity for global explict variable";
}
identity global-implict {
base variable-type;
description
"Identity for global explict variablae";
}
identity local-explict {
base variable-type;
description
"Identity for local explict variable";
}
identity local-implict {
base variable-type;
description
"Identity for local implict variable";
}
identity function-type {
description
"Possible values are:
plus, minus, mult, divide, remain.";
}
identity logical-operation-type {
description
"Possible values are:
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not, or, and.";
}
identity policy-variable-type {
description
"Possible values are:
boolean, int32, int64, uint32, uint64, string, etc.";
}
identity event-type {
description
"Base identity for event type";
}
identity frequency {
description
"Base identity for frequency";
}
identity periodic {
base frequency;
description
"Identity for periodic trigger";
}
identity scheduling {
base frequency;
description
"Identity for scheduling trigger";
}
identity logging {
description
"Base identity for logging action";
}
identity logging-notification {
base logging;
description
"Logging for event notification";
}
identity logging-set {
base logging;
description
"Logging for reset values";
}
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typedef logging-type {
type identityref {
base logging;
}
description
"Logging types";
}
typedef group-type {
type string;
description
"Group type";
}
grouping start-end-grouping {
description
"A grouping that provides start and end times for
Event objects.";
leaf start {
type yang:date-and-time;
description
"The date and time when the Event object
starts to create triggers.";
}
leaf end {
type yang:date-and-time;
description
"The date and time when the Event object
stops to create triggers.
It is generally a good idea to always configure
an end time and to refresh the end time as needed
to ensure that agents that lose connectivity to
their Controller do not continue executing Schedules
forever.";
}
}
typedef operator {
type enumeration {
enum unequal {
description
"Indicates that the comparision type is unequal to.";
}
enum equal {
description
"Indicates that the comparision type is equal to.";
}
enum less {
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description
"Indicates that the comparision type is less than.";
}
enum less-or-equal {
description
"Indicates that the comparision type is less than
or equal to.";
}
enum greater {
description
"Indicates that the comparision type is greater than.";
}
enum greater-or-equal {
description
"Indicates that the comparision type is greater than
or equal to.";
}
}
description
"definition of the operator";
}
grouping existences-trigger {
description
"A grouping that provides existence trigger";
container existences {
leaf type {
type enumeration {
enum match {
description "march";
}
enum mismatch {
description "mismatch";
}
}
description
"existence type, variable match the value or variable mismatch the value";
}
leaf policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
}
description
"Policy variable";
}
description
"Container for existence";
}
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}
grouping boolean-trigger {
description
"A grouping that provides boolean trigger";
container boolean {
leaf operator {
type operator;
description
"Comparison type.";
}
container policy-value {
container policy-argument {
choice argument {
case explict-variable {
leaf explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"explict variable";
}
}
case implict-variable {
leaf implict-variable {
type leafref {
path "/policy-variables/policy-variable/implict-variable";
}
description
"implict variable";
}
}
case value {
leaf policy-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"policy value";
}
}
description
"Choice one argument format";
}
description
"Cotainer for policy argument";
}
description
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"Container for policy value";
}
container policy-variable {
container policy-argument {
choice argument {
case explict-variable {
leaf explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"explict variable";
}
}
case implict-variable {
leaf implict-variable {
type leafref {
path "/policy-variables/policy-variable/implict-variable";
}
description
"implict variable";
}
}
description
"Choice one argument format";
}
description
"Cotainer for policy argument";
}
description
"Container for policy variable";
}
description
"Container for boolean test.";
}
}
grouping threshold-trigger {
description
"A grouping that provides threshold trigger";
container threshold {
leaf rising-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"Sets the rising threshold to the specified value,
when the current sampled value is greater than or equal to
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this threshold, and the value at the last sampling interval
was less than this threshold, the event is triggered. ";
}
leaf-list rising-policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
}
description
"List for target variable.";
}
leaf falling-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"Sets the falling threshold to the specified value.";
}
leaf-list falling-policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
}
description
"List for target variable.";
}
leaf delta-rising-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"Sets the delta rising threshold to the specified value.";
}
leaf-list delta-rising-policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
}
description
"List for target variable.";
}
leaf delta-falling-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"Sets the delta falling threshold to the specified value.";
}
leaf-list delta-falling-policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
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}
description
"List for target variable.";
}
leaf startup {
type enumeration {
enum rising {
description
"If the first sample after this
managed object becomes active is greater than or equal
to 'rising-value' and the 'startup' is equal to
'rising' then one threshold rising event is
triggered for that managed object.";
}
enum falling {
description
"If the first sample after this managed object becomes
active is less than or equal to 'falling-value' and
the 'startup' is equal to 'falling' then one
threshold falling event is triggered for that managed
object.";
}
enum rising-or-falling {
description
"That event may be triggered when the
'startup' is equal to 'rising-or-falling'.
'rising-or-falling' indicate the state value of the
managed object may less than or greater than the
specified thrshold value.";
}
}
description
"Startup setting.";
}
description
"Container for the threshold trigger condition.
Note that the threshold here may change over time
or the state value changes in either ascend order
or descend order.";
}
}
grouping trigger-grouping {
description
"A grouping that provides event trigger.";
choice test {
description
"Choice test";
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case existences {
uses existences-trigger;
}
case boolean {
uses boolean-trigger;
}
case threshold {
uses threshold-trigger;
}
}
}
container policy-variables {
list policy-variable {
key "name";
leaf name {
type string;
description
"Policy variable name";
}
leaf type {
type identityref {
base variable-type;
}
description
"Policy variable type";
}
leaf explict-variable {
type yang:xpath1.0;
description
"Explict policy variable";
}
leaf implict-variable {
type identityref {
base policy-variable-type;
}
description
"A common policy variable type, defined as an
identity.";
}
leaf policy-value {
type union {
type yang:xpath1.0;
type yang:object-identifier;
type yang:uuid;
type string;
type boolean;
type int32;
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type int64;
type uint32;
type uint64;
}
description
"Policy value";
}
description
"List for policy variable";
}
description
"Policy variables";
}
container eca {
list event {
key "name type";
leaf name {
type string;
description
"Event name";
}
leaf type {
type identityref {
base event-type;
}
description
"Type of event";
}
leaf event-description {
type string;
description
"Event description";
}
leaf group-id {
type group-type;
description
"Group Identifier";
}
leaf-list explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"Explict variable";
}
leaf clear {
type boolean;
default "false";
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description
"A flag indicate whether the event be closed";
}
container scheduled-time {
leaf type {
type identityref {
base frequency;
}
description
"Type of scheduled-time";
}
container periodic {
when "derived-from-or-self(../type, 'periodic')";
description
"A periodic timing object triggers periodically
according to a regular interval.";
leaf interval {
type uint32 {
range "1..max";
}
units "seconds";
mandatory true;
description
"The number of seconds between two triggers
generated by this periodic timing object.";
}
uses start-end-grouping;
}
container calendar-time {
when "derived-from-or-self(../type, 'scheduling')";
description
"A scheduling timing object triggers.";
leaf-list month {
type string;
description
"A set of months at which this scheduling timing
will trigger.";
}
leaf-list day-of-month {
type uint8 {
range "0..59";
}
description
"A set of days of the month at which this
scheduling timing will trigger.";
}
leaf-list day-of-week {
type uint8 {
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range "0..59";
}
description
"A set of weekdays at which this scheduling timing
will trigger.";
}
leaf-list hour {
type uint8 {
range "0..59";
}
description
"A set of hours at which the scheduling timing will
trigger.";
}
leaf-list minute {
type uint8 {
range "0..59";
}
description
"A set of minutes at which this scheduling timing
will trigger.";
}
leaf-list second {
type uint8 {
range "0..59";
}
description
"A set of seconds at which this calendar timing
will trigger.";
}
uses start-end-grouping;
}
description
"Container for frequency";
}
leaf last-event {
type leafref {
path "/eca/event/name";
}
config false;
description
"The reference to a event last executed
or being executed.";
}
leaf last-condition {
type leafref {
path "/eca/event/condition/name";
}
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config false;
description
"The reference to a condition last executed or being
executed.";
}
leaf last-action {
type leafref {
path "/eca/event/actions/action/name";
}
config false;
description
"The reference to aa action last executed or being
executed.";
}
list condition {
key "name";
leaf name {
type string;
description
"Trigger name";
}
leaf condition-description {
type string;
description
"Trigger description";
}
leaf logical-operation-type {
type identityref {
base logical-operation-type;
}
description
"The logical operation type.";
}
leaf call-event {
type leafref {
path "../../name";
}
description
"This leaf call sub-event.";
}
uses trigger-grouping;
description
"List for trigger";
}
container actions {
list action {
key "name";
leaf name {
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type string;
description
"Action Name";
}
choice action-type {
description
"Choice one action type";
case set {
container set {
leaf policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
}
description
"The target objects";
}
anydata value {
description
"Inline set content.";
}
description
"Set a value to the target";
}
}
case logging {
container logging {
leaf type {
type logging-type;
description
"Specifies the log action";
}
leaf policy-variable {
type leafref {
path "/policy-variables/policy-variable/name";
}
description
"The target objects";
}
description
"Specifies the log action";
}
}
case function-call {
container function-call {
description
"The operation is to call a function, which is of one of
a few basic predefined types, such as plus, minus,
multiply, devide, or remainder.";
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leaf function-type {
type identityref {
base function-type;
}
description
"One of the predefined basic function types, such as
plus, minus, multiply, devide, or remainder.";
}
list policy-argument {
key "name";
leaf name {
type string;
description
"Policy argument name";
}
choice argument {
case explict-variable {
leaf explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"explict variable";
}
}
case implict-variable {
leaf implict-variable {
type leafref {
path "/policy-variables/policy-variable/implict-variable";
}
description
"implict variable";
}
}
case value {
leaf policy-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"policy value";
}
}
description
"Choice one argument format";
}
description
"List for policy argument";
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}
container result {
choice argument {
case explict-variable {
leaf explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"explict variable";
}
}
case implict-variable {
leaf implict-variable {
type leafref {
path "/policy-variables/policy-variable/implict-variable";
}
description
"implict variable";
}
}
case value {
leaf policy-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"policy value";
}
}
description
"Choice one argument format";
}
description
"Container for result";
}
}
}
case rpc-call {
container rpc-call {
leaf name {
type string;
description
"The name of the YANG RPC or YANG action to be
called.";
}
container input {
list policy-argument {
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key "name";
leaf name {
type string;
description
"Policy argument name";
}
choice argument {
case explict-variable {
leaf explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"explict variable";
}
}
case implict-variable {
leaf implict-variable {
type leafref {
path "/policy-variables/policy-variable/implict-variable";
}
description
"implict variable";
}
}
case value {
leaf policy-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"policy value";
}
}
description
"Choice one argument format";
}
description
"List for policy argument";
}
description
"Container for input";
}
container output {
list policy-argument {
key "name";
leaf name {
type string;
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description
"Policy argument name";
}
choice argument {
case explict-variable {
leaf explict-variable {
type leafref {
path "/policy-variables/policy-variable/explict-variable";
}
description
"explict variable";
}
}
case implict-variable {
leaf implict-variable {
type leafref {
path "/policy-variables/policy-variable/implict-variable";
}
description
"implict variable";
}
}
case value {
leaf policy-value {
type leafref {
path "/policy-variables/policy-variable/policy-value";
}
description
"policy value";
}
}
description
"Choice one argument format";
}
description
"List for policy argument";
}
description
"Container for output";
}
description
"Container for rpc call";
}
}
}
description
"List for actions";
}
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description
"Container for Actions";
}
description
"List for Events";
}
description
"YANG data module for defining event triggers and actions for
network management purposes";
}
}
<CODE ENDS>
7. Security Considerations
The YANG modules defined in this document MAY be accessed via the
RESTCONF protocol [RFC8040] or NETCONF protocol ([RFC6241]). The
lowest RESTCONF or NETCONF layer requires that the transport-layer
protocol provides both data integrity and confidentiality, see
Section 2 in [RFC8040] and [RFC6241]. The lowest NETCONF layer is
the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH)[RFC6242] . The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC5246].
The NETCONF access control model [RFC6536] provides the means to
restrict access for particular NETCONF or RESTCONF users to a
preconfigured subset of all available NETCONF or RESTCONF protocol
operations and content.
There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
o /eca/event/name
o /eca/policy-variables/policy-variable/name
o /eca/event/actions/action/name
o /eca/event/condition/name
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8. IANA Considerations
This document registers two URIs in the IETF XML registry [RFC3688].
Following the format in [RFC3688], the following registrations are
requested to be made:
---------------------------------------------------------------------
URI: urn:ietf:params:xml:ns:yang:ietf-eca
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
---------------------------------------------------------------------
This document registers one YANG module in the YANG Module Names
registry [RFC6020].
---------------------------------------------------------------------
Name: ietf-eca
Namespace: urn:ietf:params:xml:ns:yang:ietf-eca
Prefix: eca
Reference: RFC xxxx
---------------------------------------------------------------------
9. Acknowledges
This work has benefited from the discussions of ECA Policy over the
years. In particular, the SUPA project [
https://datatracker.ietf.org/wg/supa/about/ ] provided approaches to
express high-level, possibly network-wide policies to a network
management function (within a controller, an orchestrator, or a
network element).
Igor Bryskin, Xufeng Liu, Alexander Clemm, Henk Birkholz, Tianran
Zhou contributed to an earlier version of [GNCA]. We would like to
thank the authors of that document on event response behaviors
delegation for material that assisted in thinking that helped improve
this document.
10. Objectives for existing and possible future extension
This section describes some of the design objectives for the ECA
Policy management Data Model:
o Clear and precise identification of Event types in the ECA Policy.
o Clear and precise identification of managed object (i.e., policy
variable) in the ECA Policy.
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o Allow nested ECA policy,e.g, one event to be able to call another
nested event.
o Allow the client use NETCONF/RESTCONF protocol or any other
management protocol to configure ECA Policy.
o Allow the server send updates only when the value falls within a
certain range.
o Allow the server send updates only when the value exceeds a
certain threshold for the first time but not again until the
threshold is cleared.
o Allow the client optimize the system behavior across the whole
network to meet objectives and provide some performance guarantees
for network services.
o Allow the the server provide rapid autonomic response in the
network device that can exhibit self-management properties
including self-configuration, self-healing, self-optimization, and
self-protection.
o Allow the ECA execution thread in the server use YANG Push/YANG
Push extension to communicate with the client.
11. Contributors
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Chongfeng Xie
China Telecom
Email: xiechf@ctbri.com.cn
Xiaopeng Qin
Huawei
Huawei Bld., No.156 Beiqing Rd.
Beijing 100095
China
qinxiaopeng@huawei.com
Alexander Clemm
Futurewei
Email: ludwig@clemm.org
Henk Birkholz
Fraunhofer SIT
Email: henk.birkholz@sit.fraunhofer.de
Tianran Zhou
Huawei
Email: zhoutianran@huawei.com
Aihua Guo
Individual
aihguo1@gmail.com
Nicola Sambo
Scuola Superiore Sant'Anna
Via Moruzzi 1
Pisa 56124
Italy
Email: nicola.sambo@sssup.it
Giuseppe Fioccola
Huawei Technologies
Riesstrasse, 25
Munich 80992
Germany
Email: giuseppe.fioccola@huawei.com
12. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", March 1997.
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[RFC2981] Kavasseri, R., Ed., "Event MIB", RFC 2981,
DOI 10.17487/RFC2981, October 2000,
<https://www.rfc-editor.org/info/rfc2981>.
[RFC3460] Moore, B., Ed., "Policy Core Information Model (PCIM)
Extensions", RFC 3460, DOI 10.17487/RFC3460, January 2003,
<https://www.rfc-editor.org/info/rfc3460>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6370] Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
Profile (MPLS-TP) Identifiers", RFC 6370,
DOI 10.17487/RFC6370, September 2011,
<https://www.rfc-editor.org/info/rfc6370>.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<https://www.rfc-editor.org/info/rfc6536>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC7952] Lhotka, L., "Defining and Using Metadata with YANG",
RFC 7952, DOI 10.17487/RFC7952, August 2016,
<https://www.rfc-editor.org/info/rfc7952>.
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[RFC8328] Liu, W., Xie, C., Strassner, J., Karagiannis, G., Klyus,
M., Bi, J., Cheng, Y., and D. Zhang, "Policy-Based
Management Framework for the Simplified Use of Policy
Abstractions (SUPA)", RFC 8328, DOI 10.17487/RFC8328,
March 2018, <https://www.rfc-editor.org/info/rfc8328>.
Appendix A. ECA Model Usage Example
+---------------------------+
| Management System |
+---------------------------+
|
ECA |
Model |
|
V
+----------------------^-----+
| Managed Device | |
| | |
| //--\\ Condition--+ |
| | Event| / \ |
| | |----->|Actions |
| \\--// \ / |
| ---- |
+----------------------------+
For Example:
The management system push down one ECA policy to control interface
behavior in the managed device that supports NETCONF protocol
operation.
The explicit policy variable of Event "interface-state-monitoring" is
set to "/if:interfaces/if:interface[if:name='eth0']", the trigger
list contains two conditions: 1)The publisher sends a push-change-
update notification; 2) the value of "in-errors" of
interface[name='eth0'] exceeded the pre-configured threshold. When
these conditions are met, corresponding action will be performed,
i.e. disable interface[name='eth0']. The XML examples are shown as
below:
<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
<eventTime>2017-10-25T08:22:33.44Z</eventTime>
<push-change-update
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push">
<id>89</id>
<datastore-changes>
<yang-patch>
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<patch-id>0</patch-id>
<edit>
<edit-id>edit1</edit-id>
<operation>replace</operation>
<target>/ietf-interfaces:interfaces</target>
<value>
<interfaces
xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface>
<name>eth0</name>
<oper-status>up</oper-status>
</interface>
</interfaces>
</value>
</edit>
</yang-patch>
</datastore-changes>
</push-change-update>
</notification>
<eca>
<event>
<name>interface-state-monitoring</name>
<type>interface-exception</type>
<scheduled-time>
<periodic>
<interval>10m</interval>
</periodic>
</scheduled-time>
<condition>
<name>state-push-change</name>
<condition-description>sent a yang push
\changed notification</condition-description>
<test>
<existence>
<policy-variable>/yp:notification/yp:push-change-update/yp:id[id=89]\
/yp:datastore-changes/.../yp:target="/ietf-interfaces:interfaces='eth0'\
</policy-variable>
</existence>
</test>
</explict-variable>
<condition>
<name>evaluate-in-errors</name>
<condition-description>evaluate the number of
the error packets</condition-description>
<test>
<boolean>
<operator>greater-or-equal</operator>
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<policy-value>
<policy-argument>
<policy-value>100</policy-value>
</policy-argument>
</policy-value>
<policy-variable>
<policy-argument>
<explict-variable>/if:interfaces/if:interface[if:name='eth0']\
/if:statistic/if:in-errors</explict-variable>
</policy-argument>
</policy-variable>
</boolean>
</test>
</condition>
<action>
<name>foo</name>
<set>
<policy-variable>/if:interfaces/if:interface[if:name='eth0']</policy-variable>
<value>
<interfaces>
<interface>
<name>eth0</name>
<enable>false</enable>
</interface>
</interfaces>
</value>
</set>
</action>
</event>
</eca>
Appendix B. Usage Example of Reusing Trigger-Grouping in smarter filter
The "ietf-eca.yang" module defines a set of groupings for a generic
condition expression. It is intended that these groupings can be
reused by other models that require the trigger conditions, for
example, in some subscription and notification cases, many
applications do not require every update, only updates that are of
certain interest. The following example describe how to reuse the
"ietf-eca" module to define the subscription and notification smarter
filter.
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import ietf-subscribed-notifications {
prefix sn;
}
import ietf-eca {
prefix eca;
}
augment "/sn:subscriptions/sn:subscription" {
description "add the smart filter container";
container smart-filter {
description "It concludes filter configurations";
uses eca:trigger-grouping;
}
}
The tree diagrams:
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module: ietf-smart-filter
augment /sn:subscriptions/sn:subscription:
+--rw smart-filter
+-- (test)?
+--:(existences)
| +-- existences
| +-- type? enumeration
| +-- policy-variable?
| -> /policy-variables/policy-variable/name
+--:(boolean)
| +-- boolean
| +-- operator? operator
| +-- policy-value
| | +-- policy-argument
| | +-- (argument)?
| | +--:(explict-variable)
| | | +-- explict-variable? leafref
| | +--:(implict-variable)
| | | +-- implict-variable? leafref
| | +--:(value)
| | +-- policy-value? leafref
| +-- policy-variable
| +-- policy-argument
| +-- (argument)?
| +--:(explict-variable)
| | +-- explict-variable? leafref
| +--:(implict-variable)
| +-- implict-variable? leafref
+--:(threshold)
+-- threshold
+-- rising-value? leafref
+-- rising-policy-variable*
| -> /policy-variables/policy-variable/name
+-- falling-value? leafref
+-- falling-policy-variable*
| -> /policy-variables/policy-variable/name
+-- delta-rising-value? leafref
+-- delta-rising-policy-variable*
| -> /policy-variables/policy-variable/name
+-- delta-falling-value? leafref
+-- delta-falling-policy-variable*
| -> /policy-variables/policy-variable/name
+-- startup? enumeration
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Appendix C. Changes between Revisions
v05 - v06
o Decouple ECA model from NETCONF protocol and make it applicable to
other network mangement protocols.
o Move objective section to the last section with additional generic
objectives.
v04 - v05
o Harmonize with draft-bryskin and add additional attributes in the
models (e.g., policy variable, func call enhancement, rpc
execution);
o ECA conditions part harmonization;
o ECA Event, Condition, Action, Policy Variable and Value
definition;
o Change ietf-event.yang into ietf-eca.yang and remove ietf-event-
trigger.yang
v02 - v03
o Usage Example Update: add an usage example to introduce how to
reuse the ietf-event-trigger module to define the subscription-
notification smarter filter.
v01 - v02
o Introduce the group-id which allow group a set of events that can
be executed together
o Change threshold trigger condition into variation trigger
condition to further clarify the difference between boolean
trigger condition and variation trigger condition.
o Module structure optimization.
o Usage Example Update.
v00 - v01
o Separate ietf-event-trigger.yang from Event management modeland
ietf-event.yang and make it reusable in other YANG models.
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o Clarify the difference between boolean trigger condition and
threshold trigger condition.
o Change evt-smp-min and evt-smp-max into min-data-object and max-
data-object in the data model.
Authors' Addresses
Michael Wang
Huawei Technologies,Co.,Ltd
101 Software Avenue, Yuhua District
Nanjing 210012
China
Email: wangzitao@huawei.com
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Igor Bryskin
Individual
Email: i_bryskin@yahoo.com
Xufeng Liu
Volta Networks
Email: xufeng.liu.ietf@gmail.com
Benoit Claise
Cisco
Email: bclaise@cisco.com
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