| NETMOD Working Group | M. Wang |
| Internet-Draft | Q. Wu |
| Intended status: Standards Track | Huawei |
| Expires: May 20, 2020 | C. Xie |
| China Telecom | |
| I. Bryskin | |
| Individual | |
| X. Liu | |
| Volta Networks | |
| A. Clemm | |
| Futurewei | |
| H. Birkholz | |
| Fraunhofer SIT | |
| T. Zhou | |
| Huawei | |
| November 17, 2019 |
A YANG Data model for ECA Policy Management
draft-wwx-netmod-event-yang-05
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. Policy discussed in RFC8328 are classified into imperative policy and declarative policy, ECA policy is an typical example of imperative policy. This document defines an YANG data model for the ECA policy management. The ECA policy YANG provides the ability for the network management function (within a controller, an orchestrator, or a network element) to control the configuration and monitor state change and take simple and instant action on the network element when a trigger condition on the system state is met.
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 May 20, 2020.
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.
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.
[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. 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:
This document defines a ECA Policy management YANG data model. The ECA Policy YANG provides the ability for the network management function (within a controller, an orchestrator, or a network element) to control the configurations and monitor state parameters and take simple and instant action on the network element 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].
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.
This document uses the following terms:
Tree diagrams used in this document follow the notation defined in [RFC8340].
This section describes some of the design objectives for the ECA Policy management Data Model:
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:
In these three trigger conditions, existence with type set to object change is similar to on Push change.
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.
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 NETCONF server by the NETCONF client. If the action is rejected by the server duing ECA policy execution, the action should be rolled back and cleaned up.
ECA policy variable 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:
The following operations are allowed with/on a PV:
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
+--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
The model structure for the Policy Variable is shown below:
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:
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* [event-name type]
+--rw event-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 next-scheduled-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/event-name
<policy-variable> <relation> <policy-value> or <policy-variable1> <relation> <policy-variable2> relation is one of the comparison operations from the set: ==, !=, >, <, >=, <=
ECA 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, ECA condition can be specified as logical combinations of the following three ECA condition expressions:
If the value of the monitored object crosses a threshold multiple times in succession, the managed device triggers a network 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.
+--rw condition* [name]
| +--rw name string
| +--rw condition-description? string
| +--rw logical-operation-type? identityref
| +--rw call-event? -> ../../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
The model structure for the ECA Condition is shown below:
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:
Multiple ECA Actions could be triggered by a single ECA event.
Any given ECA Condition or Action may appear in more than one ECAs.
+--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)
| | +--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
The model structure for the ECA Action is shown below:
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
| +-- (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
| | +--:(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* [event-name type]
+--rw event-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 next-scheduled-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/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? -> ../../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
| +--:(variation)
| +--rw variation
| +--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
+--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)
| | +--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
The following tree diagrams [RFC8340] provide an overview of the data model for the "ietf-eca" 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 xxx Working Group";
contact
"Zitao Wang: wangzitao@huawei.com
Qin Wu: bill.wu@huawei.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.
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 2019-11-11 {
description
"Initial revision.";
reference
"foo";
}
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:
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";
}
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 {
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";
}
}
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
"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
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";
}
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";
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;
type int64;
type uint32;
type uint64;
}
description
"Policy value";
}
description
"List for policy variable";
}
description
"Policy variables";
}
container eca {
list event {
key "event-name type";
leaf event-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";
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 next-scheduled-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 {
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/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";
}
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 "../../event-name";
}
description
"This leaf call sub-event.";
}
uses trigger-grouping;
description
"List for trigger";
}
container actions {
list action {
key "name";
leaf name {
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.";
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";
}
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 {
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;
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";
}
description
"Container for Actions";
}
description
"List for Events";
}
description
"YANG data module for defining event triggers and actions for
network management purposes";
}
}
<CODE ENDS>
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:
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 ---------------------------------------------------------------------
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.
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
+---------------------------+
| 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)receiver received 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>
<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</event-name>
<type>interface-exception</type>
<explict-variable>/if:interfaces/if:interface[if:name='eth0']</explict-variable>
<scheduled-time>10m</scheduled-time>
<condition>
<name>state-push-change</name>
<condition-description>received 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>
<call-event>interface-state-chang</call-event>
<condition-description>evaluate the number of
the packets that contained errors</condition-description>
<test>
<boolean>
<operator>greater-or-equal</operator>
<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>
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.
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:
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
v04 -v05
v02 - v03
v01 - v02
v00 - v01