9.2 KiB
VNF AutoHealing triggered by FaultNotification
Overview
Tacker supports AutoHealing using
FaultNotification interface. When fault events occur in
VIM, VIM notifies fault event to Tacker via the interface. Tacker takes
initiative of AutoHealing. Tacker checks faultID attribute in the fault
event and determines whether AutoHealing should be performed. In case of
performing AutoHealing, VMs are deleted or created.
Configuration
FaultNotification is disabled by default. To enable
FaultNotification, be sure to set true for
CONF.server_notification.server_notification.
| Configuration | Default | Description |
|---|---|---|
CONF.server_notification.server_notification |
false | Enable FaultNotification interface. |
CONF.server_notification.uri_path_prefix |
/server_notification | Uri path prefix string for FaultNotification interface. When changing this configuration, server_notification description in api-paste.ini must be changed to the same value. |
CONF.server_notification.timer_interval |
20 | When multiple fault events for a vnf instance are notified in the
timer_interval seconds, Tacker packs these notifications
into single event. By doing this, Tacker can avoid making too many
healing request. |
System
FaultNotification AutoHealing needs external service called Server Notifier.
The Server Notifier is a monitoring service that is
implemented by each operators, thus it is not included in Tacker. When
the Server Notifier detects fault events in VIM, it will send
FaultNotification to Tacker.
Setting FaultNotification interface uri or enabling monitoring for
the Server Notifier is performed along the vnf lifecycle. So Tacker
provides a sample implementation of the mgmt driver script
to achieve interface registration and enabling monitoring.
+--------------------------+
| Client (NFVO) +--------+
+--------------------------+ | 1. Vnf instantiation
+-----------------------------------v--------------------------------+
| 2.Create VM Tacker |
6.FaultNotification | 3.Interface registration (in mgmt driver) |
+--------------> 7.Perform Healing |
| | 8.Delete failed VM and Create new VM |
| +---------------------------------------+-------------+--------------+
| +----------------------------------------------+ |
+------|-------|------------------------------------------------------------|--------------+
| | | 4.Start monitoring +---------------+--------+ VIM/NFVI |
| | | | | |
| +--+-------v--+ +--------v----+ +------v------+ |
| | Server | 5.Detects fault event | +--------+ | | +--------+ | |
| | Notifier +-------------------------> VNF | | | | VNF | | |
| | | | +--------+ | | +--------+ | |
| | | | VM | | VM | |
| +-------------+ +-------------+ +-------------+ |
+------------------------------------------------------------------------------------------+For details about the interface, please refer to1.
Mgmt driver script
Sample mgmt driver script to achieve interface registration and
enabling monitoring is
tacker/sol_refactored/mgmt_drivers/server_notification.py
Put this script into target VNF package and Server Notifier can detect fault event on the VNF.
LCM interface
The LCM interface is modified to set parameters for Server Notifier.
The additionalParams must be set when using
FaultNotification.
- Name: Instantiate VNF task
Description: This task resource represents theInstantiate VNFoperation. The client can use this resource to instantiate a VNF instance.Only the additionalParams for FaultNotification are described here.
Method type: POST
URL for the resource: /vnflcm/v2/vnf_instances/ {vnfInstanceId}/instantiate
Request:Attribute name (InstantiateVnfRequest) Data type Cardinality Description additionalParams KeyValuePairs (inlined) 0..1 Additional input parameters for the instantiation process, specific to the VNF being instantiated. >ServerNotifierUri String 1 Base Uri for ServerNotifier. >ServerNotifierFaultID String 1..N List of string that indicates which type of alarms to detect.
The value of ServerNotifierUri and
ServerNotifierFaultID are stored in
instantiatedVnfInfo of vnfInstance. The values can be shown
with vnflcm show command. For example:
$ openstack vnflcm show 6fd264ea-78fb-4862-90c0-1a9597734d95 --os-tacker-api-version 2
+-----------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-----------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ID | 6fd264ea-78fb-4862-90c0-1a9597734d95 |
| Instantiated Vnf Info | { |
| | .... |
| | "metadata": { |
| | "ServerNotifierUri": "http://localhost:9990/server_notification", |
| | "ServerNotifierFaultID": "1234" |
| | } |
| | .... |
+-----------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+Auto Healing
When fault events occur in VIM, ServerNotifier notifies fault event to Tacker via the FaultNotification interface.
Tacker checks fault_id attribute in the fault event and
determines whether AutoHealing should be performed. In case of
performing AutoHealing, VMs are deleted and created via Heat. The client
is no need to handle healing.
Using Vendor Specific Plugin
ServerNotification plugin can be replaced with a vendor specific function. To replace a plugin, change the configurations below. The replaced class must be a subclass of tacker.sol_refactored.common.monitoring_plugin_base.MonitoringPlugin.
| Configuration | Default | Description |
|---|---|---|
CONF.server_notification.server_notification_package |
tacker.sol_refactored.common.server_notification | Package name for server notification. |
CONF.server_notification.server_notification_class |
ServerNotification | Class name for server notification. |