| NETMOD Working Group | H. Birkholz |
| Internet-Draft | Fraunhofer SIT |
| Intended status: Standards Track | Q. Wu |
| Expires: November 14, 2020 | Huawei |
| I. Bryskin | |
| Individual | |
| X. Liu | |
| Volta Networks | |
| B. Claise | |
| Cisco | |
| May 13, 2020 |
A YANG Data model for ECA Policy Management
draft-wwx-netmod-event-yang-07
This document defines a YANG data model for the Event Condition Action (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.
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This Internet-Draft will expire on November 14, 2020.
Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved.
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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.
Event-driven policy management can be used to monitor state changes of managed objects or resource across a wide range of devices and automatic trigger of rules in response to events so as to better service assurance for customers and 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 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].
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:
This document uses the following terms:
Tree diagrams used in this document follow the notation defined in [RFC8340].
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 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.
ECA policy variable (PV) generically represents datastore states that change (or "varie"), 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 also used in condition expressions.
+--rw policy-variables | +--rw policy-variable* [name] | +--rw name string | +--rw (type-choice)? | | +--:(implicit) | | | +--rw implicit-variable identityref | | +--:(explicit) | | | +--rw explicit-variable yang:xpath1.0 | +--rw value? <anydata>
The model structure for the Policy Variable is shown below:
The ECA Event is any subscribable event notification either explicitly defined in a YANG module (e.g., alarm model) supported by the server or a event stream conveyed to the server via YANG Push subscription. 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:
A client may define an event of interest by making use of YANG PUSH subscription. Specifically, the client may configure an ECA event according to the ECA model specifying the event's name, as well as the name of corresponding PUSH subscrition. In this case the server is expected to:
All events (specified in at least one ECA pushed to the server) are required to be constantly monitored by the server. One way to think of this is that the server subscribes to its own publications with respect to all events that are associated with at least one ECA.
The model structure for the ECA Event is shown below:
+--rw event* [name type]
+--rw name string
+--rw policy-variable?
| -> /gnca/policy-variables/policy-variable/name
+--rw local-policy-variable?
| -> /gnca/ecas/eca/policy-variable/name
+--rw (type-choice)?
| +--:(stream)
| +--rw stream
| | +--rw name? string
| | +--rw filter* string
| +--:(alarm-event-stream)
| | +--rw resource resource
| | +--rw alarm-type-id alarm-type-id
| | +--rw alarm-type-qualifier alarm-type-qualifier
| | +--rw alt-resource resource
| | +--rw related-alarm*
| | +--rw impacted-resource* resource
| | +--rw root-cause-resource* resource
| | +--rw time yang:date-and-time
| | +--rw percieved-severity severity-with-clear
| | +--rw alarm-text alarm-text
| +--:(timer)
| | +--rw time-schedule!
| | +--rw start? yang:date-and-time
| | +--rw repeat-interval? uint32
The ECA Condition is the logical expression that is specified in a form of Xpath expression and evaluated to TRUE or FALSE. The XPath expression specifies an arbitrary logical/mathematical expression; The elements of the ECA Condition expression are referred by the XPaths pointing to referred datastore states.
The ECA Condition expression in the form of XPath expression allows for specifying a condition of arbitrary complexity as a single string with an XPath expression, in which pertinent PVs and datastore states are referred to by their respective positions in the YANG tree.
ECA Conditions are associated with ECA Events and evaluated only within event threads triggered by the event detection.
When an ECA Condition is evaluated to TRUE, the associated ECA Action is executed.
+--rw conditions | +--rw condition* [name] | +--rw name string | +--rw (expression-choice)? | +--:(xpath) | +--rw condition-xpath? string
The model structure for the condition is shown below:
The ECA 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:
Two points are worth noting:
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-element* [name] | | +--rw name string | | +--rw action-type? identityref | | +--rw (action-operation)? | | +--:(action) | | | +--rw action-name? | | | -> /eca/actions/action/name | | +--:(set) | | | +--rw name? string | | | +--rw policy-variable* [name] | | | +--rw name string | | | +--rw policy-argument | | | +--rw policy-value <anydata> | | +--:(function-call) | | | +--rw function-call | | | +--rw function-type? identityref | | | +--rw src | | | | +--rw policy-argument | | | +--rw dst | | | +--rw policy-argument | | +--:(rpc-operation) | | | +--rw rpc-operation | | | +--rw name? string | | | +--rw nc-action-xpath? string | | | +--rw policy-variable* [name] | | | +--rw name string | | | +--rw policy-argument | | +--:(notify-operation) | | +--rw notify-operation | | +--rw name? string | | +--rw policy-variable* [name] | | +--rw name string | | +--rw policy-argument | +--rw time-schedule | +--rw start? yang:date-and-time | +--rw repeat-interval? string
The model structure for the actions is shown below:
An ECA container includes:
It could be said that the main idea of the ECA is decoupling the place where the network control logic is defined from the place where it is executed. In previous sections of this document it is assumed that the network control logic is defined by a client and pushed to and executed by the network (server). This is accomplished via ECA scripts, which are essentially bunches of regular NETCONF style operations (such as get, set, call rpc) and event notifications glued together via Policy Variables, PVs.
module: ietf-eca
+--rw gnca
+--rw policy-variables
| +--rw policy-variable* [name]
| +--rw name string
| +--rw (type-choice)?
| | +--:(implicit)
| | | +--rw implicit-variable identityref
| | +--:(explicit)
| | | +--rw explicit-variable yang:xpath1.0
| +--rw value? <anydata>
+--rw event* [name type]
| +--rw name string
| +--rw policy-variable?
| | -> /gnca/policy-variables/policy-variable/name
| +--rw local-policy-variable?
| | -> /gnca/ecas/eca/policy-variable/name
| +--rw (type-choice)?
| | +--:(stream)
| | +--rw stream
| | | +--rw name? string
| | | +--rw filter* string
| | | +--rw remote-publisher!
| | | +--rw address? inet:ip-address-no-zone
| | | +--rw port? inet:port-number
| | | +--rw transport? sn:transport
| | +--:(alarm-event-stream)
| | | +--rw resource resource
| | | +--rw alarm-type-id alarm-type-id
| | | +--rw alarm-type-qualifier alarm-type-qualifier
| | | +--rw alt-resource resource
| | | +--rw related-alarm*
| | | +--rw impacted-resource* resource
| | | +--rw root-cause-resource* resource
| | | +--rw time yang:date-and-time
| | | +--rw percieved-severity severity-with-clear
| | | +--rw alarm-text alarm-text
| | +--:(timer)
| | | +--rw time-schedule!
| | | +--rw start? yang:date-and-time
| | | +--rw repeat-interval? uint32
+--rw conditions
| +--rw condition* [name]
| +--rw name string
| +--rw (expression-choice)?
| +--:(xpath)
| +--rw condition-xpath? string
+--rw actions
| +--rw action* [name]
| +--rw name string
| +--rw action-element* [name]
| | +--rw name string
| | +--rw action-type? identityref
| | +--rw (action-operation)?
| | +--:(action)
| | | +--rw action-name?
| | | -> /eca/actions/action/name
| | +--:(set)
| | | +--rw name? string
| | | +--rw policy-variable* [name]
| | | +--rw name string
| | | +--rw policy-argument
| | | +--rw policy-value <anydata>
| | +--:(function-call)
| | | +--rw function-call
| | | +--rw function-type? identityref
| | | +--rw src
| | | | +--rw policy-argument
| | | +--rw dst
| | | +--rw policy-argument
| | +--:(rpc-operation)
| | | +--rw rpc-operation
| | | +--rw name? string
| | | +--rw nc-action-xpath? string
| | | +--rw policy-variable* [name]
| | | +--rw name string
| | | +--rw policy-argument
| | +--:(notify-operation)
| | +--rw notify-operation
| | +--rw name? string
| | +--rw policy-variable* [name]
| | +--rw name string
| | +--rw policy-argument
| +--rw time-schedule
| +--rw start? yang:date-and-time
| +--rw repeat-interval? string
+--rw ecas
| +--rw eca* [name]
| +--rw name string
| +--rw event-name leafref
| +--rw policy-variable* [name]
| | +--rw name string
| | +--rw (type-choice)?
| | +--:(implicit)
| | | +--rw implicit-variable identityref
| | +--:(explicit)
| | | +--rw explicit-variable yang:xpath1.0
| | +--rw value? <anydata>
| +--rw condition-action* [name]
| | +--rw name string
| | +--rw condition? -> /gnca/conditions/condition/name
| | +--rw action? -> /gnca/actions/action/name
| +--rw cleanup-condition-action* [name]
| | +--rw name string
| | +--rw condition? -> /gnca/conditions/condition/name
| | +--rw action? -> /gnca/actions/action/name
| +---x start
| +---x stop
| +---x pause
| +---x resume
| +---x next-action
| +--ro execution* [id]
| +--ro id uint32
| +--ro oper-status? oper-status
| +--ro start-time?
| | yang:date-and-time
| +--ro stop-time?
| | yang:date-and-time
| +--ro next-scheduled-time?
| | yang:date-and-time
| +--ro last-condition-action?
| | -> ../../condition-action/name
| +--ro last-condition?
| | -> ../../condition-action/condition
| +--ro last-action?
| | -> ../../condition-action/action
| +--ro last-cleanup-condition-action?
| -> ../../cleanup-condition-action/name
+--rw eca-scripts
| +--rw eca-script* [script-name]
| +--rw script-name string
| +--rw eca* [eca-name]
| +--rw eca-name -> /gnca/ecas/eca/name
notifications:
+---n eca-execution
+--ro oper-status oper-status
+--ro name string
+--ro policy-variable* [name]
+--ro name string
+--ro policy-argument
| +--ro type? identityref
| +--ro (argument-choice)?
| +--:(policy-constant)
| | +--ro constant? string
| +--:(policy-variable)
| | +--ro policy-variable? -> /gnca/policy-variables/policy-variable/name
| +--:(local-policy-variable)
| | +--ro local-policy-variable? -> /gnca/ecas/eca/policy-variable/name
| +--:(xpath)
| +--ro xpath? string
+--ro value? <anydata>
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 "gncd";
import ietf-yang-types {
prefix "yang";
}
import ietf-inet-types {
prefix "inet";
}
import ietf-alarms {
prefix "al";
}
import ietf-subscribed-notifications {
prefix "sn";
}
organization
"IETF Network Configuration (NETCONF) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Qin Wu
<mailto:bill.wu@huawei.com>
Editor: Igor Bryskin
<mailto:Igor.Bryskin@huawei.com>
Editor: Henk Birkholz
<mailto:henk.birkholz@sit.fraunhofer.de>
Editor: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>
Editor: Benoit Claise
<mailto:bclaise@cisco.com>
Editor: Alexander Clemm
<mailto:ludwig@clemm.org>";
description
"Event Condition Action (ECA) model.";
revision 2018-06-22 {
description "Initial revision";
reference "RFC XXXX";
}
/*
* Typedefs
*/
identity argument-type {
description
"Possible values are:
constant, variable, or datastore state.";
}
identity comparison-type {
description
"Possible values are:
equal, not-equal, greater, greater-equal, less, less-equal.";
}
identity logical-operation-type {
description
"Possible values are:
not, or, and.";
}
identity function-type {
description
"Possible values are:
plus, minus, mult, divide, remain.";
}
identity content-moving-operation-type {
description
"Possible values are:
copy, iterate, insert.";
}
identity action-type {
description
"Possible values are:
action, content-move, function-call, rpc, notify.";
}
identity policy-variable-type {
description
"Possible values are:
boolean, int32, int64, uint32, uint64, string, etc.";
}
/*
* Typedefs
*/
typedef oper-status {
type enumeration {
enum completed {
description "Completed with no error.";
}
enum running {
description "Currently with no error.";
}
enum sleeping {
description "Sleeping because of time schedule.";
}
enum paused {
description "Paused by the operator.";
}
enum stoped {
description "Stopped by the operator.";
}
enum failed {
description "Failed with errors.";
}
enum error-handling {
description
"Asking the operator to handle an error.";
}
}
description
"The operational status of an ECA execution.";
}
/*
* Groupings
*/
grouping policy-variable-attributes {
description
"Defining the policy variable attributes, including name, type
and value. These attributes are used as part of the Policy
Variable (PV) definition.";
leaf name {
type string;
description
"A string to uniquely identify a Policy Variable (PV), either
globally for a global PV, or within the soope of ECA for a
local PV.";
}
choice type-choice {
description
"The type of a policy variable may be either a common
primative type like boolean or a type from existing
schema node referenced by an XPath string.";
case implicit {
leaf implicit-variable {
type identityref {
base policy-variable-type;
}
description
"A common policy variable type, defined as an
identity.";
}
}
case explicit {
leaf explicit-variable {
type yang:xpath1.0;
description
"A XPath string, referencing a schema node, whose
type is used as the type of the policy variable.";
}
}
}
anydata value {
description
"The value of the policy variable, in a format that is
determined by the policy type.";
}
} // policy-variable-attributes
grouping policy-argument {
description
"Defining a policy argument, which can be used in a comparison
or an action.";
container policy-argument {
description
"Containing the attributes of a policy argument.";
leaf type {
type identityref {
base argument-type;
}
description
"Identifies the argument type.";
}
choice argument-choice {
description
"Argument formation options, depending on the policy
type.";
case policy-constant {
leaf constant {
type string;
description
"The constant value of the policy argument.";
}
}
case policy-variable {
leaf policy-variable {
type leafref {
path "/gncd/policy-variables/"
+ "policy-variable/name";
}
description
"A reference to a global policy variable, which
is shared by all ECA scripts.";
}
}
case local-policy-variable {
leaf local-policy-variable {
type leafref {
path "/gncd/ecas/eca/policy-variable/name";
}
description
"A reference to a local policy variable, which
is kept within an ECA instance, and appears/
disappears with start/stop of the ECA execution.";
}
}
case xpath {
leaf xpath {
type string;
description
"An XPath string, referencing the data in the
datastore.";
}
}
}
}
} // policy-argument
grouping action-element-attributes {
description
"Grouping of action element attributes.";
leaf action-type {
type identityref {
base action-type;
}
description
"Identifies the action type.";
}
choice action-operation {
description
"The operation choices that an ECA Action can take.";
case action {
leaf action-name {
type leafref {
path "/gncd/actions/action/name";
}
description
"The operation is to execute a configured ECA Action.";
}
} // action
case set-operation {
container set-operation {
description
"The operation is to set policy variable into a value.";
leaf name {
type string;
description
"Name of the subscribed YANG notification.";
}
list policy-variable {
key name;
description
"A list of policy arguments carried in the notification
message.";
leaf name {
type string;
description
"A string name used as the list key to form a list
of policy arguments.";
}
uses policy-argument;
anydata value {
description
"The value of the policy variable, in a format that is
determined by the policy type.";
}
}
}
} // notify-operation
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.";
}
container src {
description
"The source policy argument.";
uses policy-argument;
}
container dst {
description
"The distination policy argument.";
uses policy-argument;
}
}
} // function-call
case rpc-operation {
container rpc-operation {
description
"The operation is to call an RPC, which is defined by
a YANG module supported by the server.";
leaf name {
type string;
description
"The name of the YANG RPC or YANG action to be
called.";
}
leaf nc-action-xpath {
type string;
description
"The location where the YANG action is defined.
This is used if and only if a YANG action is called.
This leaf is not set when a YANG RPC is called.";
}
list policy-variable {
key name;
description
"A list of policy arguments used as the input or output
parameters passed to the RPC.";
leaf name {
type string;
description
"A string name used as the list key to form a list
of policy arguments.";
}
uses policy-argument;
}
}
} // rpc-operation
case notify-operation {
container notify-operation {
description
"The operation is to send a YANG notification.";
leaf name {
type string;
description
"Name of the subscribed YANG notification.";
}
list policy-variable {
key name;
description
"A list of policy arguments carried in the notification
message.";
leaf name {
type string;
description
"A string name used as the list key to form a list
of policy arguments.";
}
uses policy-argument;
}
}
} // notify-operation
}
} // action-element-attributes
grouping time-schedule-container {
description
"Grouping to define a container of a time schedule.";
container time-schedule {
presence
"Presence indicates that the timer is enabled.";
description
"Specifying the time schedule to execute an ECA Action, or
trigger an event.";
leaf start {
type yang:date-and-time;
description
"The start time of the ECA Action, or the specified event.
If not specified, the ECA Action is executed
immediately when it is called, or the event is triggered
immediately.";
}
leaf repeat-interval {
type string {
pattern
'(R\d*/)?P(\d+Y)?(\d+M)?(\d+W)?(\d+D)?T(\d+H)?'
+ '(\d+M)?(\d+S)?';
}
description
"The repeat interval to execute this ECA Action, or to
trigger the event.
The repeat interval is a string in ISO 8601 format,
representing a delay duration or a repeated delay
duration.
If not specified, the ECA Action or the evetn trigger
is executed without delay and without repetition.";
}
} // time-schedule
}
/*
* Data nodes
*/
container gncd {
description
"Top level container for Generalized Network Control Automation
(gncd).";
// policy-variables
container policy-variables {
description
"Container of global Policy Variables (PVs).";
list policy-variable {
key name;
description
"A list of global Policy Variables (PVs), with a string
name as the entry key.";
uses policy-variable-attributes;
}
} // policy-variables
container events {
description
"Container of ECA events.";
list event {
key name;
description
"A list of events used as the triggers of ECAs.";
leaf name {
type string;
description
"The name of the event.";
}
leaf policy-variable {
type leafref {
path "/gncd/policy-variables/"
+ "policy-variable/name";
}
description
"Optional association to a global policy variable, which
is shared by all ECA scripts.";
}
leaf local-policy-variable {
type leafref {
path "/gncd/ecas/eca/policy-variable/name";
}
description
"Optional associateion to a local policy variable, which
is kept within an ECA instance, and appears/
disappears with start/stop of the ECA execution.";
}
choice type-choice {
description
"The type of an event, including subscribed stream.";
case stream {
container stream {
description
"The information of the subscribed stream.";
leaf name {
type string;
description
"The name of a stream subscribed and reported in
the model
ietf-subscribed-notifications.";
}
leaf-list filter {
type yang:xpath1.0;
description
"A list of filters to be applied to the subscribed
stream.";
}
container remote-publisher {
presence
"The presence indicates the publisher is remote.
Otherwise, the publisher is the local system.";
description
"If the subscribed stream is from a remote server,
this container specifies the information of the
remote server.";
leaf address {
type inet:host;
description
"IP address of the remote publisher.";
}
leaf port {
type inet:port-number;
description
"The port number on the publisher for a
subscription request RPC.";
}
leaf transport {
type sn:transport;
description
"The transport used between this system and
remote publisher.";
}
}
}
}
case alarm-event-stream {
uses al:common-alarm-parameters;
uses al:alarm-state-change-parameters;
}
case timer {
uses time-schedule-container {
description
"Specifying the time schedule to trigger the event.
If not specified, the event is not triggered.";
}
}
}
}
}
container conditions {
description
"Container of ECA Conditions.";
list condition {
key name;
description
"A list of ECA Conditions.";
leaf name {
type string;
description
"A string name to uniquely identify an ECA Condition
globally.";
}
choice expression-choice {
description
"The choices of expression format to specify a condition,
which can be either a XPath string.";
case xpath {
leaf condition-xpath {
type string;
description
"A XPath string, representing a logical expression,
which can contain comparisons of datastore values
and logical operations in the XPath format.";
}
} // xpath
} // expression-choice
} // condition
} // conditions
container actions {
description
"Container of ECA Actions.";
list action {
key name;
description
"A list of ECA Actions.";
leaf name {
type string;
description
"A string name to uniquely identify an ECA Action
globally.";
}
list action-element {
key name;
description
"A list of elements contained in an ECA Action. ";
leaf name {
type string;
description
"A string name to uniquely identify the action element
within the scope of an ECA action.";
}
uses action-element-attributes;
}
uses time-schedule-container {
description
"Specifying the time schedule to execute this ECA
Action.
If not specified, the ECA Action is executed immediately
when it is called.";
}
}
} // actions
container ecas {
description
"Container of ECAs.";
list eca {
key name;
description
"A lis of ECAs";
leaf name {
type string;
description
"A string name to uniquely identify an ECA globally.";
}
leaf event-name {
type string;
mandatory true;
description
"The name of an event that triggers the execution of
this ECA.";
}
list policy-variable {
key name;
description
"A list of ECA local Policy Variables (PVs), with a
string name as the entry key.";
uses policy-variable-attributes;
leaf is-static {
type boolean;
description
"'true' if the PV is static; 'false' if the PV is
dynamic.
A dynamic PV appears/disappears with the start/stop
of the ECA execution; a static PV exists as long as
the ECA is configured.";
}
}
list condition-action {
key name;
description
"A list of Condition-Actions, which are configured
conditions each with associated actions to be executed
if the condition is evaluated to TRUE";
leaf name {
type string;
description
"A string name uniquely identify a Condition-Action
within this ECA.";
}
leaf condition {
type leafref {
path "/gncd/conditions/condition/name";
}
description
"The reference to a configured condition.";
}
leaf action {
type leafref {
path "/gncd/actions/action/name";
}
description
"The reference to a configured action.";
}
} // condition-action
list cleanup-condition-action {
key name;
description
"A list of Condition-Actions, which are configured
conditions each with associated actions to be executed
if the condition is evaluated to TRUE.
This is the exception handler of this ECA, and is
evaluated and executed in case any Action from the
normal Condition-Action list was attempted and rejected
by the server.";
leaf name {
type string;
description
"A string name uniquely identify a Condition-Action
within this ECA.";
}
leaf condition {
type leafref {
path "/gncd/conditions/condition/name";
}
description
"The reference to a configured condition.";
}
leaf action {
type leafref {
path "/gncd/actions/action/name";
}
description
"The reference to a configured action.";
}
} // cleanup-condition-action
action start {
description
"Start to execute this ECA.";
}
action stop {
description
"Stop the execution of this ECA.";
}
action pause {
description
"Pause the execution of this ECA.";
}
action resume {
description
"Resume the execution of this ECA.";
}
action next-action {
description
"Resume the execution of this ECA to complete the next
action.";
}
list execution {
key id;
config false;
description
"A list of executions that this ECA has completed,
are currently running, and will start in the scheduled
future.";
leaf id {
type uint32;
description
"The ID to uniquely identify an execution of the ECA.";
}
leaf oper-status {
type oper-status;
description
"The running status of the execution.";
}
leaf start-time {
type yang:date-and-time;
description
"The time when the ECA started.";
}
leaf stop-time {
type yang:date-and-time;
description
"The time when the ECA completed or stopped.";
}
leaf next-scheduled-time {
type yang:date-and-time;
description
"The next time when the ECA is scheduled to resume.";
}
leaf last-condition-action {
type leafref {
path "../../condition-action/name";
}
description
"The reference to a condition-action last executed
or being executed.";
}
leaf last-condition {
type leafref {
path "../../condition-action/condition";
}
description
"The reference to a condition last executed or being
executed.";
}
leaf last-action {
type leafref {
path "../../condition-action/action";
}
description
"The reference to aa action last executed or being
executed.";
}
leaf last-cleanup-condition-action {
type leafref {
path "../../cleanup-condition-action/name";
}
description
"The reference to a cleanup-condition-action last
executed or being executed.";
}
}
}
} // ecas
container eca-scripts {
description
"Container of ECA Scripts.";
list eca-script {
key script-name;
description
"A list of ECA Script.";
leaf script-name {
type string;
description
"A string name to uniquely identify an ECA Script.";
}
list eca {
key eca-name;
description
"A list of ECAs contained in this ECA Script.";
leaf eca-name {
type leafref {
path "/gncd/ecas/eca/name";
}
description
"The reference to a configured ECA.";
}
}
}
} // eca-scripts
leaf running-script {
type leafref {
path "/gncd/eca-scripts/eca-script/script-name";
}
description
"The reference to the ECA script that is currently running.";
}
}
/*
* NOTIFICATIONS
*/
notification eca-execution {
description
"This notification is to send the result of an ECA execution
that is specified to use notify-operation.";
leaf oper-status {
type oper-status;
mandatory true;
description
"The running status of the execution.";
}
leaf name {
type string;
mandatory true;
description
"Name of the subscribed YANG notification.";
}
list policy-variable {
key name;
description
"A list of policy arguments carried in the notification
message.";
leaf name {
type string;
description
"A string name used as the list key to form a list
of policy arguments.";
}
uses policy-argument;
anydata value {
description
"The value of the policy variable, in a format that is
determined by the policy type.";
}
}
}
}
<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: gnca Reference: RFC xxxx ---------------------------------------------------------------------
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.
Alexander Clemm Futurewei Email: ludwig@clemm.org Michale Wang Huawei Email:wangzitao@huawei.com Chongfeng Xie China Telecom Email: xiechf@ctbri.com.cn Xiaopeng Qin Huawei Huawei Bld., No.156 Beiqing Rd. Beijing 100095 China qinxiaopeng@huawei.com 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
Here are two examples of Condition Expression:
TE metric of Link L in Topology T greater than 100, it can be expressed as follows: "/nw:networks/nw:network[network-id='T']/nt:link[link-id='L']/tet:te/tet:te-link-attributes/tet:te-delay-metric > 100"
(a) a condition that only includes data store states and constants, for example:
Allocated bandwidth of Link L in Topology T greater than 75% of what is stored in Policy Variable B, it can be expressed as follows: "/nw:networks/nw:network[network-id='T']/nt:link[link-id='L']/tet:te/tet:te-link-attributes/tet:max-resv-link-bandwidth > (ietf-eca:policy-variables/policy-variable[name='B']/value) * 0.75"
(b) a condition that also includes a Policy Variable, for example:
+---------------------------+
| Management System |
+---------------------------+
|
ECA |
Model |
|
V
+----------------------^-----+
| Managed Device | |
| | |
| //--\\ Condition--+ |
| | Event| / \ |
| | |----->|Actions |
| \\--// \ / |
| ---- |
+----------------------------+
The management system pushes down one ECA policy to control temperature sensor behavior in the managed device or the router chasis that supports NETCONF/RESTCONF protocol operation. The event type is chosen as alarm-event-stream, each alarm instance is identified by 3 tuples (resource, alarm-type identifier, and alarm-type qualifier), in this example, resource instance-identifier is set to '/hw:hardware/hw:component[hw:name='fan1']', the alarm-type is set to 'enviromental-alarm', the alarm-type qualifier is set to 'fan-temperature-anamoly'. The event name is set to 'fan-temperature-monitoring', when the temperature of fan component within the managed device cross preconfigured threshold 80 degree Celsius , the managed device needs to send one time log notification to the management system. The XML example snippet is shown as below:
<gnca>
<events>
<event>
<name>fan-temperature-monitoring</name>
<resource>/hw:hardware/hw:component[hw:name='fan1']</resource>
<alarm-type-id>enviromental-alarm</alarm-type-id>
<alarm-type-qualifier>fan-temperature-anamoly</alarm-type-qualifier>
</event>
</events>
<conditions>
<condition>
<name>fan-temperature-condition</name>
<condition-xpath>
/hw:hardware/hw:component[hw:name='fan1']/hw:sensor-data/hw:value > 80 &&
/hw:hardware/hw:component[hw:name='fan1']/hw:sensor-data/hw:value-type='celsius'
</condition-xpath>
</condition>
</conditions>
<actions>
<action>
<name>fan-temperature-anamoly</name>
<action-element>
<name>log-report</name>
<notify-operation>
<name>anamoly-report</name>
<policy-argument>
<xpath>/hw:hardware/hw:component[hw:name='fan1']/hw:sensor-data/hw:value</xpath>
</policy-argument>
</notify-operation>
</action-element>
</action>
</actions>
<ecas>
<eca>
<name>fan-temperature-handling</name>
<event-name>fan-temperature-monitoring</event-name>
<condition-action>
<name>temperature-cross-threshold-handling</name>
<condition>fan-temperature-condition</condition>
<action>fan-temperature-anamoly</action>
</condition-action>
</eca>
</ecas>
</gnca>
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