1 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
2 .. http://creativecommons.org/licenses/by/4.0
4 Detailed architecture and interface specification
5 =================================================
7 This section describes a detailed implementation plan, which is based on the
8 high level architecture introduced in Section 3. Section 5.1 describes the
9 functional blocks of the Doctor architecture, which is followed by a high level
10 message flow in Section 5.2. Section 5.3 provides a mapping of selected existing
11 open source components to the building blocks of the Doctor architecture.
12 Thereby, the selection of components is based on their maturity and the gap
13 analysis executed in Section 4. Sections 5.4 and 5.5 detail the specification of
14 the related northbound interface and the related information elements. Finally,
15 Section 5.6 provides a first set of blueprints to address selected gaps required
16 for the realization functionalities of the Doctor project.
23 This section introduces the functional blocks to form the VIM. OpenStack was
24 selected as the candidate for implementation. Inside the VIM, 4 different
25 building blocks are defined (see :numref:`figure6`).
27 .. figure:: images/figure6.png
36 The Monitor module has the responsibility for monitoring the virtualized
37 infrastructure. There are already many existing tools and services (e.g. Zabbix)
38 to monitor different aspects of hardware and software resources which can be
39 used for this purpose.
44 The Inspector module has the ability a) to receive various failure notifications
45 regarding physical resource(s) from Monitor module(s), b) to find the affected
46 virtual resource(s) by querying the resource map in the Controller, and c) to
47 update the state of the virtual resource (and physical resource).
49 The Inspector has drivers for different types of events and resources to
50 integrate any type of Monitor and Controller modules. It also uses a failure
51 policy database to decide on the failure selection and aggregation from raw
52 events. This failure policy database is configured by the Administrator.
54 The reason for separation of the Inspector and Controller modules is to make the
55 Controller focus on simple operations by avoiding a tight integration of various
56 health check mechanisms into the Controller.
61 The Controller is responsible for maintaining the resource map (i.e. the mapping
62 from physical resources to virtual resources), accepting update requests for the
63 resource state(s) (exposing as provider API), and sending all failure events
64 regarding virtual resources to the Notifier. Optionally, the Controller has the
65 ability to force the state of a given physical resource to down in the resource
66 mapping when it receives failure notifications from the Inspector for that
67 given physical resource.
68 The Controller also re-calculates the capacity of the NVFI when receiving a
69 failure notification for a physical resource.
71 In a real-world deployment, the VIM may have several controllers, one for each
72 resource type, such as Nova, Neutron and Cinder in OpenStack. Each controller
73 maintains a database of virtual and physical resources which shall be the master
74 source for resource information inside the VIM.
79 The focus of the Notifier is on selecting and aggregating failure events
80 received from the controller based on policies mandated by the Consumer.
81 Therefore, it allows the Consumer to subscribe for alarms regarding virtual
82 resources using a method such as API endpoint. After receiving a fault
83 event from a Controller, it will notify the fault to the Consumer by referring
84 to the alarm configuration which was defined by the Consumer earlier on.
86 To reduce complexity of the Controller, it is a good approach for the
87 Controllers to emit all notifications without any filtering mechanism and have
88 another service (i.e. Notifier) handle those notifications properly. This is the
89 general philosophy of notifications in OpenStack. Note that a fault message
90 consumed by the Notifier is different from the fault message received by the
91 Inspector; the former message is related to virtual resources which are visible
92 to users with relevant ownership, whereas the latter is related to raw devices
93 or small entities which should be handled with an administrator privilege.
95 The northbound interface between the Notifier and the Consumer/Administrator is
96 specified in :ref:`impl_nbi`.
104 The detailed work flow for fault management is as follows (see also :numref:`figure7`):
106 1. Request to subscribe to monitor specific virtual resources. A query filter
107 can be used to narrow down the alarms the Consumer wants to be informed
109 2. Each subscription request is acknowledged with a subscribe response message.
110 The response message contains information about the subscribed virtual
111 resources, in particular if a subscribed virtual resource is in "alarm"
113 3. The NFVI sends monitoring events for resources the VIM has been subscribed
114 to. Note: this subscription message exchange between the VIM and NFVI is not
115 shown in this message flow.
116 4. Event correlation, fault detection and aggregation in VIM.
117 5. Database lookup to find the virtual resources affected by the detected fault.
118 6. Fault notification to Consumer.
119 7. The Consumer switches to standby configuration (STBY)
120 8. Instructions to VIM requesting certain actions to be performed on the
121 affected resources, for example migrate/update/terminate specific
122 resource(s). After reception of such instructions, the VIM is executing the
123 requested action, e.g. it will migrate or terminate a virtual resource.
124 a. Query request from Consumer to VIM to get information about the current
125 status of a resource.
126 b. Response to the query request with information about the current status of
127 the queried resource. In case the resource is in "fault" state, information
128 about the related fault(s) is returned.
130 In order to allow for quick reaction to failures, the time interval between
131 fault detection in step 3 and the corresponding recovery actions in step 7 and 8
132 shall be less than 1 second.
134 .. figure:: images/figure7.png
138 Fault management work flow
140 .. figure:: images/figure8.png
144 Fault management scenario
146 :numref:`figure8` shows a more detailed message flow (Steps 4 to 6) between
147 the 4 building blocks introduced in :ref:`impl_fb`.
149 4. The Monitor observed a fault in the NFVI and reports the raw fault to the
151 The Inspector filters and aggregates the faults using pre-configured
155 a) The Inspector queries the Resource Map to find the virtual resources
156 affected by the raw fault in the NFVI.
157 b) The Inspector updates the state of the affected virtual resources in the
159 c) The Controller observes a change of the virtual resource state and informs
160 the Notifier about the state change and the related alarm(s).
161 Alternatively, the Inspector may directly inform the Notifier about it.
163 6. The Notifier is performing another filtering and aggregation of the changes
164 and alarms based on the pre-configured alarm configuration. Finally, a fault
165 notification is sent to northbound to the Consumer.
169 .. figure:: images/figure9.png
173 NFVI maintenance work flow
175 The detailed work flow for NFVI maintenance is shown in :numref:`figure9`
176 and has the following steps. Note that steps 1, 2, and 5 to 8a in the NFVI
177 maintenance work flow are very similar to the steps in the fault management work
178 flow and share a similar implementation plan in Release 1.
180 1. Subscribe to fault/maintenance notifications.
181 2. Response to subscribe request.
182 3. Maintenance trigger received from administrator.
183 4. VIM switches NFVI resources to "maintenance" state. This, e.g., means they
184 should not be used for further allocation/migration requests
185 5. Database lookup to find the virtual resources affected by the detected
186 maintenance operation.
187 6. Maintenance notification to Consumer.
188 7. The Consumer switches to standby configuration (STBY)
189 8. Instructions from Consumer to VIM requesting certain recovery actions to be
190 performed (step 8a). After reception of such instructions, the VIM is
191 executing the requested action in order to empty the physical resources (step
193 9. Maintenance response from VIM to inform the Administrator that the physical
194 machines have been emptied (or the operation resulted in an error state).
195 10. Administrator is coordinating and executing the maintenance operation/work
197 a) Query request from Administrator to VIM to get information about the
198 current state of a resource.
199 b) Response to the query request with information about the current state of
200 the queried resource(s). In case the resource is in "maintenance" state,
201 information about the related maintenance operation is returned.
203 .. figure:: images/figure10.png
207 NFVI Maintenance implementation plan
209 :numref:`figure10` shows a more detailed message flow (Steps 3 to 6 and 9)
210 between the 4 building blocks introduced in Section 5.1..
212 3. The Administrator is sending a StateChange request to the Controller residing
214 4. The Controller queries the Resource Map to find the virtual resources
215 affected by the planned maintenance operation.
218 a) The Controller updates the state of the affected virtual resources in the
219 Resource Map database.
221 b) The Controller informs the Notifier about the virtual resources that will
222 be affected by the maintenance operation.
224 6. A maintenance notification is sent to northbound to the Consumer.
228 9. The Controller informs the Administrator after the physical resources have
233 Implementation plan for OPNFV Release 1
234 ---------------------------------------
239 :numref:`figure11` shows the implementation plan based on OpenStack and
240 related components as planned for Release 1. Hereby, the Monitor can be realized
241 by Zabbix. The Controller is realized by OpenStack Nova [NOVA]_, Neutron
242 [NEUT]_, and Cinder [CIND]_ for compute, network, and storage,
243 respectively. The Inspector can be realized by Monasca [MONA]_ or a simple
244 script querying Nova in order to map between physical and virtual resources. The
245 Notifier will be realized by Ceilometer [CEIL]_ receiving failure events
246 on its notification bus.
248 :numref:`figure12` shows the inner-workings of Ceilometer. After receiving
249 an "event" on its notification bus, first a notification agent will grab the
250 event and send a "notification" to the Collector. The collector writes the
251 notifications received to the Ceilometer databases.
253 In the existing Ceilometer implementation, an alarm evaluator is periodically
254 polling those databases through the APIs provided. If it finds new alarms, it
255 will evaluate them based on the pre-defined alarm configuration, and depending
256 on the configuration, it will hand a message to the Alarm Notifier, which in
257 turn will send the alarm message northbound to the Consumer. :numref:`figure12`
258 also shows an optimized work flow for Ceilometer with the goal to
259 reduce the delay for fault notifications to the Consumer. The approach is to
260 implement a new notification agent (called "publisher" in Ceilometer
261 terminology) which is directly sending the alarm through the "Notification Bus"
262 to a new "Notification-driven Alarm Evaluator (NAE)" (see Sections 5.6.2 and
263 5.6.3), thereby bypassing the Collector and avoiding the additional delay of the
264 existing polling-based alarm evaluator. The NAE is similar to the OpenStack
265 "Alarm Evaluator", but is triggered by incoming notifications instead of
266 periodically polling the OpenStack "Alarms" database for new alarms. The
267 Ceilometer "Alarms" database can hold three states: "normal", "insufficient
268 data", and "fired". It is representing a persistent alarm database. In order to
269 realize the Doctor requirements, we need to define new "meters" in the database
272 .. figure:: images/figure11.png
276 Implementation plan in OpenStack (OPNFV Release 1 ”Arno”)
279 .. figure:: images/figure12.png
283 Implementation plan in Ceilometer architecture
289 For NFVI Maintenance, a quite similar implementation plan exists. Instead of a
290 raw fault being observed by the Monitor, the Administrator is sending a
291 Maintenance Request through the northbound interface towards the Controller
292 residing in the VIM. Similar to the Fault Management use case, the Controller
293 (in our case OpenStack Nova) will send a maintenance event to the Notifier (i.e.
294 Ceilometer in our implementation). Within Ceilometer, the same workflow as
295 described in the previous section applies. In addition, the Controller(s) will
296 take appropriate actions to evacuate the physical machines in order to prepare
297 them for the planned maintenance operation. After the physical machines are
298 emptied, the Controller will inform the Administrator that it can initiate the
299 maintenance. Alternatively the VMs can just be shut down and boot up on the
300 same host after maintenance is over. There needs to be policy for administrator
301 to know the plan for VMs in maintenance.
306 This section introduces all attributes and information elements used in the
307 messages exchange on the northbound interfaces between the VIM and the VNFO and
310 Note: The information elements will be aligned with current work in ETSI NFV IFA
314 Simple information elements:
316 * SubscriptionID (Identifier): identifies a subscription to receive fault or maintenance
318 * NotificationID (Identifier): identifies a fault or maintenance notification.
319 * VirtualResourceID (Identifier): identifies a virtual resource affected by a
320 fault or a maintenance action of the underlying physical resource.
321 * PhysicalResourceID (Identifier): identifies a physical resource affected by a
322 fault or maintenance action.
323 * VirtualResourceState (String): state of a virtual resource, e.g. "normal",
324 "maintenance", "down", "error".
325 * PhysicalResourceState (String): state of a physical resource, e.g. "normal",
326 "maintenance", "down", "error".
327 * VirtualResourceType (String): type of the virtual resource, e.g. "virtual
328 machine", "virtual memory", "virtual storage", "virtual CPU", or "virtual
330 * FaultID (Identifier): identifies the related fault in the underlying physical
331 resource. This can be used to correlate different fault notifications caused
332 by the same fault in the physical resource.
333 * FaultType (String): Type of the fault. The allowed values for this parameter
334 depend on the type of the related physical resource. For example, a resource
335 of type "compute hardware" may have faults of type "CPU failure", "memory
336 failure", "network card failure", etc.
337 * Severity (Integer): value expressing the severity of the fault. The higher the
338 value, the more severe the fault.
339 * MinSeverity (Integer): value used in filter information elements. Only faults
340 with a severity higher than the MinSeverity value will be notified to the
342 * EventTime (Datetime): Time when the fault was observed.
343 * EventStartTime and EventEndTime (Datetime): Datetime range that can be used in
344 a FaultQueryFilter to narrow down the faults to be queried.
345 * ProbableCause (String): information about the probable cause of the fault.
346 * CorrelatedFaultID (Integer): list of other faults correlated to this fault.
347 * isRootCause (Boolean): Parameter indicating if this fault is the root for
348 other correlated faults. If TRUE, then the faults listed in the parameter
349 CorrelatedFaultID are caused by this fault.
350 * FaultDetails (Key-value pair): provides additional information about the
351 fault, e.g. information about the threshold, monitored attributes, indication
352 of the trend of the monitored parameter.
353 * FirmwareVersion (String): current version of the firmware of a physical
355 * HypervisorVersion (String): current version of a hypervisor.
356 * ZoneID (Identifier): Identifier of the resource zone. A resource zone is the
357 logical separation of physical and software resources in an NFVI deployment
358 for physical isolation, redundancy, or administrative designation.
359 * Metadata (Key-value pair): provides additional information of a physical
360 resource in maintenance/error state.
362 Complex information elements (see also UML diagrams in :numref:`figure13`
363 and :numref:`figure14`):
365 * VirtualResourceInfoClass:
367 + VirtualResourceID [1] (Identifier)
368 + VirtualResourceState [1] (String)
369 + Faults [0..*] (FaultClass): For each resource, all faults
370 including detailed information about the faults are provided.
372 * FaultClass: The parameters of the FaultClass are partially based on ETSI TS
373 132 111-2 (V12.1.0) [*]_, which is specifying fault management in 3GPP, in
374 particular describing the information elements used for alarm notifications.
376 - FaultID [1] (Identifier)
377 - FaultType [1] (String)
378 - Severity [1] (Integer)
379 - EventTime [1] (Datetime)
380 - ProbableCause [1] (String)
381 - CorrelatedFaultID [0..*] (Identifier)
382 - FaultDetails [0..*] (Key-value pair)
384 .. [*] http://www.etsi.org/deliver/etsi_ts/132100_132199/13211102/12.01.00_60/ts_13211102v120100p.pdf
386 * SubscribeFilterClass
388 - VirtualResourceType [0..*] (String)
389 - VirtualResourceID [0..*] (Identifier)
390 - FaultType [0..*] (String)
391 - MinSeverity [0..1] (Integer)
393 * FaultQueryFilterClass: narrows down the FaultQueryRequest, for example it
394 limits the query to certain physical resources, a certain zone, a given fault
395 type/severity/cause, or a specific FaultID.
397 - VirtualResourceType [0..*] (String)
398 - VirtualResourceID [0..*] (Identifier)
399 - FaultType [0..*] (String)
400 - MinSeverity [0..1] (Integer)
401 - EventStartTime [0..1] (Datetime)
402 - EventEndTime [0..1] (Datetime)
404 * PhysicalResourceStateClass:
406 - PhysicalResourceID [1] (Identifier)
407 - PhysicalResourceState [1] (String): mandates the new state of the physical
409 - Metadata [0..*] (Key-value pair)
411 * PhysicalResourceInfoClass:
413 - PhysicalResourceID [1] (Identifier)
414 - PhysicalResourceState [1] (String)
415 - FirmwareVersion [0..1] (String)
416 - HypervisorVersion [0..1] (String)
417 - ZoneID [0..1] (Identifier)
418 - Metadata [0..*] (Key-value pair)
420 * StateQueryFilterClass: narrows down a StateQueryRequest, for example it limits
421 the query to certain physical resources, a certain zone, or a given resource
422 state (e.g., only resources in "maintenance" state).
424 - PhysicalResourceID [1] (Identifier)
425 - PhysicalResourceState [1] (String)
426 - ZoneID [0..1] (Identifier)
430 Detailed northbound interface specification
431 -------------------------------------------
433 This section is specifying the northbound interfaces for fault management and
434 NFVI maintenance between the VIM on the one end and the Consumer and the
435 Administrator on the other ends. For each interface all messages and related
436 information elements are provided.
438 Note: The interface definition will be aligned with current work in ETSI NFV IFA
441 All of the interfaces described below are produced by the VIM and consumed by
442 the Consumer or Administrator.
444 Fault management interface
445 ^^^^^^^^^^^^^^^^^^^^^^^^^^
447 This interface allows the VIM to notify the Consumer about a virtual resource
448 that is affected by a fault, either within the virtual resource itself or by the
449 underlying virtualization infrastructure. The messages on this interface are
450 shown in :numref:`figure13` and explained in detail in the following
453 Note: The information elements used in this section are described in detail in
456 .. figure:: images/figure13.png
460 Fault management NB I/F messages
463 SubscribeRequest (Consumer -> VIM)
464 __________________________________
466 Subscription from Consumer to VIM to be notified about faults of specific
467 resources. The faults to be notified about can be narrowed down using a
472 - SubscribeFilter [1] (SubscribeFilterClass): Optional information to narrow
473 down the faults that shall be notified to the Consumer, for example limit to
474 specific VirtualResourceID(s), severity, or cause of the alarm.
476 SubscribeResponse (VIM -> Consumer)
477 ___________________________________
479 Response to a subscribe request message including information about the
480 subscribed resources, in particular if they are in "fault/error" state.
484 * SubscriptionID [1] (Identifier): Unique identifier for the subscription. It
485 can be used to delete or update the subscription.
486 * VirtualResourceInfo [0..*] (VirtualResourceInfoClass): Provides additional
487 information about the subscribed resources, i.e., a list of the related
488 resources, the current state of the resources, etc.
490 FaultNotification (VIM -> Consumer)
491 ___________________________________
493 Notification about a virtual resource that is affected by a fault, either within
494 the virtual resource itself or by the underlying virtualization infrastructure.
495 After reception of this request, the Consumer will decide on the optimal
496 action to resolve the fault. This includes actions like switching to a hot
497 standby virtual resource, migration of the fault virtual resource to another
498 physical machine, termination of the faulty virtual resource and instantiation
499 of a new virtual resource in order to provide a new hot standby resource. In
500 some use cases the Consumer can leave virtual resources on failed host to be
501 booted up again after fault is recovered. Existing resource management
502 interfaces and messages between the Consumer and the VIM can be used for those
503 actions, and there is no need to define additional actions on the Fault
504 Management Interface.
508 * NotificationID [1] (Identifier): Unique identifier for the notification.
509 * VirtualResourceInfo [1..*] (VirtualResourceInfoClass): List of faulty
510 resources with detailed information about the faults.
512 FaultQueryRequest (Consumer -> VIM)
513 ___________________________________
515 Request to find out about active alarms at the VIM. A FaultQueryFilter can be
516 used to narrow down the alarms returned in the response message.
520 * FaultQueryFilter [1] (FaultQueryFilterClass): narrows down the
521 FaultQueryRequest, for example it limits the query to certain physical
522 resources, a certain zone, a given fault type/severity/cause, or a specific
525 FaultQueryResponse (VIM -> Consumer)
526 ____________________________________
528 List of active alarms at the VIM matching the FaultQueryFilter specified in the
533 * VirtualResourceInfo [0..*] (VirtualResourceInfoClass): List of faulty
534 resources. For each resource all faults including detailed information about
535 the faults are provided.
540 The NFVI maintenance interfaces Consumer-VIM allows the Consumer to subscribe to
541 maintenance notifications provided by the VIM. The related maintenance interface
542 Administrator-VIM allows the Administrator to issue maintenance requests to the
543 VIM, i.e. requesting the VIM to take appropriate actions to empty physical
544 machine(s) in order to execute maintenance operations on them. The interface
545 also allows the Administrator to query the state of physical machines, e.g., in
546 order to get details in the current status of the maintenance operation like a
549 The messages defined in these northbound interfaces are shown in :numref:`figure14`
550 and described in detail in the following subsections.
552 .. figure:: images/figure14.png
556 NFVI maintenance NB I/F messages
558 SubscribeRequest (Consumer -> VIM)
559 __________________________________
561 Subscription from Consumer to VIM to be notified about maintenance operations
562 for specific virtual resources. The resources to be informed about can be
563 narrowed down using a subscribe filter.
567 * SubscribeFilter [1] (SubscribeFilterClass): Information to narrow down the
568 faults that shall be notified to the Consumer, for example limit to specific
569 virtual resource type(s).
571 SubscribeResponse (VIM -> Consumer)
572 ___________________________________
574 Response to a subscribe request message, including information about the
575 subscribed virtual resources, in particular if they are in "maintenance" state.
579 * SubscriptionID [1] (Identifier): Unique identifier for the subscription. It
580 can be used to delete or update the subscription.
581 * VirtualResourceInfo [0..*] (VirtalResourceInfoClass): Provides additional
582 information about the subscribed virtual resource(s), e.g., the ID, type and
583 current state of the resource(s).
585 MaintenanceNotification (VIM -> Consumer)
586 _________________________________________
588 Notification about a physical resource switched to "maintenance" state. After
589 reception of this request, the Consumer will decide on the optimal action to
590 address this request, e.g., to switch to the standby (STBY) configuration.
594 * VirtualResourceInfo [1..*] (VirtualResourceInfoClass): List of virtual
595 resources where the state has been changed to maintenance.
597 StateChangeRequest (Administrator -> VIM)
598 _________________________________________
600 Request to change the state of a list of physical resources, e.g. to
601 "maintenance" state, in order to prepare them for a planned maintenance
606 * PhysicalResourceState [1..*] (PhysicalResourceStateClass)
608 StateChangeResponse (VIM -> Administrator)
609 __________________________________________
611 Response message to inform the Administrator that the requested resources are
612 now in maintenance state (or the operation resulted in an error) and the
613 maintenance operation(s) can be executed.
617 * PhysicalResourceInfo [1..*] (PhysicalResourceInfoClass)
619 StateQueryRequest (Administrator -> VIM)
620 ________________________________________
622 In this procedure, the Administrator would like to get the information about
623 physical machine(s), e.g. their state ("normal", "maintenance"), firmware
624 version, hypervisor version, update status of firmware and hypervisor, etc. It
625 can be used to check the progress during firmware update and the confirmation
626 after update. A filter can be used to narrow down the resources returned in the
631 * StateQueryFilter [1] (StateQueryFilterClass): narrows down the
632 StateQueryRequest, for example it limits the query to certain physical
633 resources, a certain zone, or a given resource state.
635 StateQueryResponse (VIM -> Administrator)
636 _________________________________________
638 List of physical resources matching the filter specified in the
643 * PhysicalResourceInfo [0..*] (PhysicalResourceInfoClass): List of physical
644 resources. For each resource, information about the current state, the
645 firmware version, etc. is provided.
648 Detailed southbound interface specification
649 -------------------------------------------
651 This section is specifying the southbound interfaces for fault management
652 between the Monitors and the Inspector.
653 Although southbound interfaces should be flexible to handle various events from
654 different types of Monitors, we define unified event API in order to improve
655 interoperability between the Monitors and the Inspector.
656 This is not limiting implementation of Monitor and Inspector as these could be
657 extended in order to support failures from intelligent inspection like prediction.
659 Note: The interface definition will be aligned with current work in ETSI NFV IFA
662 Fault event interface
663 ^^^^^^^^^^^^^^^^^^^^^
665 This interface allows the Monitors to notify the Inspector about an event which
666 was captured by the Monitor and may effect resources managed in the VIM.
672 Event notification including fault description.
673 The entity of this notification is event, and not fault or error specifically.
674 This allows us to use generic event format or framework build out of Doctor project.
675 The parameters below shall be mandatory, but keys in 'Details' can be optional.
679 * Time [1]: Datetime when the fault was observed in the Monitor.
680 * Type [1]: Type of event that will be used to process correlation in Inspector.
681 * Details [0..1]: Details containing additional information with Key-value pair style.
682 Keys shall be defined depending on the Type of the event.
690 'time': '2016-04-12T08:00:00',
691 'type': 'compute.host.down',
693 'hostname': 'compute-1',
694 'source': 'sample_monitor',
695 'cause': 'link-down',
696 'severity': 'critical',
698 'monitor_id': 'monitor-1',
699 'monitor_event_id': '123',
704 Optional parameters in 'Details':
706 * Hostname: the hostname on which the event occurred.
707 * Source: the display name of reporter of this event. This is not limited to monitor, other entity can be specified such as 'KVM'.
708 * Cause: description of the cause of this event which could be different from the type of this event.
709 * Severity: the severity of this event set by the monitor.
710 * Status: the status of target object in which error occurred.
711 * MonitorID: the ID of the monitor sending this event.
712 * MonitorEventID: the ID of the event in the monitor. This can be used by operator while tracking the monitor log.
713 * RelatedTo: the array of IDs which related to this event.
715 Also, we can have bulk API to receive multiple events in a single HTTP POST
716 message by using the 'events' wrapper as follows:
723 'time': '2016-04-12T08:00:00',
724 'type': 'compute.host.down',
728 'time': '2016-04-12T08:00:00',
729 'type': 'compute.host.nic.error',
739 This section is listing a first set of blueprints that have been proposed by the
740 Doctor project to the open source community. Further blueprints addressing other
741 gaps identified in Section 4 will be submitted at a later stage of the OPNFV. In
742 this section the following definitions are used:
744 * "Event" is a message emitted by other OpenStack services such as Nova and
745 Neutron and is consumed by the "Notification Agents" in Ceilometer.
746 * "Notification" is a message generated by a "Notification Agent" in Ceilometer
747 based on an "event" and is delivered to the "Collectors" in Ceilometer that
748 store those notifications (as "sample") to the Ceilometer "Databases".
750 Instance State Notification (Ceilometer) [*]_
751 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
753 The Doctor project is planning to handle "events" and "notifications" regarding
754 Resource Status; Instance State, Port State, Host State, etc. Currently,
755 Ceilometer already receives "events" to identify the state of those resources,
756 but it does not handle and store them yet. This is why we also need a new event
757 definition to capture those resource states from "events" created by other
760 This BP proposes to add a new compute notification state to handle events from
761 an instance (server) from nova. It also creates a new meter "instance.state" in
764 .. [*] https://etherpad.opnfv.org/p/doctor_bps
766 Event Publisher for Alarm (Ceilometer) [*]_
767 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
769 **Problem statement:**
771 The existing "Alarm Evaluator" in OpenStack Ceilometer is periodically
772 querying/polling the databases in order to check all alarms independently from
773 other processes. This is adding additional delay to the fault notification
774 send to the Consumer, whereas one requirement of Doctor is to react on faults
777 The existing message flow is shown in :numref:`figure12`: after receiving
778 an "event", a "notification agent" (i.e. "event publisher") will send a
779 "notification" to a "Collector". The "collector" is collecting the
780 notifications and is updating the Ceilometer "Meter" database that is storing
781 information about the "sample" which is capured from original "event". The
782 "Alarm Evaluator" is periodically polling this databases then querying "Meter"
783 database based on each alarm configuration.
785 In the current Ceilometer implementation, there is no possibility to directly
786 trigger the "Alarm Evaluator" when a new "event" was received, but the "Alarm
787 Evaluator" will only find out that requires firing new notification to the
788 Consumer when polling the database.
790 **Change/feature request:**
792 This BP proposes to add a new "event publisher for alarm", which is bypassing
793 several steps in Ceilometer in order to avoid the polling-based approach of
794 the existing Alarm Evaluator that makes notification slow to users.
796 After receiving an "(alarm) event" by listening on the Ceilometer message
797 queue ("notification bus"), the new "event publisher for alarm" immediately
798 hands a "notification" about this event to a new Ceilometer component
799 "Notification-driven alarm evaluator" proposed in the other BP (see Section
802 Note, the term "publisher" refers to an entity in the Ceilometer architecture
803 (it is a "notification agent"). It offers the capability to provide
804 notifications to other services outside of Ceilometer, but it is also used to
805 deliver notifications to other Ceilometer components (e.g. the "Collectors")
806 via the Ceilometer "notification bus".
808 **Implementation detail**
810 * "Event publisher for alarm" is part of Ceilometer
811 * The standard AMQP message queue is used with a new topic string.
812 * No new interfaces have to be added to Ceilometer.
813 * "Event publisher for Alarm" can be configured by the Administrator of
814 Ceilometer to be used as "Notification Agent" in addition to the existing
816 * Existing alarm mechanisms of Ceilometer can be used allowing users to
817 configure how to distribute the "notifications" transformed from "events",
818 e.g. there is an option whether an ongoing alarm is re-issued or not
821 .. [*] https://etherpad.opnfv.org/p/doctor_bps
823 Notification-driven alarm evaluator (Ceilometer) [*]_
824 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
826 **Problem statement:**
828 The existing "Alarm Evaluator" in OpenStack Ceilometer is periodically
829 querying/polling the databases in order to check all alarms independently from
830 other processes. This is adding additional delay to the fault notification send
831 to the Consumer, whereas one requirement of Doctor is to react on faults as fast
834 **Change/feature request:**
836 This BP is proposing to add an alternative "Notification-driven Alarm Evaluator"
837 for Ceilometer that is receiving "notifications" sent by the "Event Publisher
838 for Alarm" described in the other BP. Once this new "Notification-driven Alarm
839 Evaluator" received "notification", it finds the "alarm" configurations which
840 may relate to the "notification" by querying the "alarm" database with some keys
841 i.e. resource ID, then it will evaluate each alarm with the information in that
844 After the alarm evaluation, it will perform the same way as the existing "alarm
845 evaluator" does for firing alarm notification to the Consumer. Similar to the
846 existing Alarm Evaluator, this new "Notification-driven Alarm Evaluator" is
847 aggregating and correlating different alarms which are then provided northbound
848 to the Consumer via the OpenStack "Alarm Notifier". The user/administrator can
849 register the alarm configuration via existing Ceilometer API [*]_. Thereby, he
850 can configure whether to set an alarm or not and where to send the alarms to.
852 **Implementation detail**
854 * The new "Notification-driven Alarm Evaluator" is part of Ceilometer.
855 * Most of the existing source code of the "Alarm Evaluator" can be re-used to
857 * No additional application logic is needed
858 * It will access the Ceilometer Databases just like the existing "Alarm
860 * Only the polling-based approach will be replaced by a listener for
861 "notifications" provided by the "Event Publisher for Alarm" on the Ceilometer
863 * No new interfaces have to be added to Ceilometer.
866 .. [*] https://etherpad.opnfv.org/p/doctor_bps
867 .. [*] https://wiki.openstack.org/wiki/Ceilometer/Alerting
869 Report host fault to update server state immediately (Nova) [*]_
870 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
872 **Problem statement:**
874 * Nova state change for failed or unreachable host is slow and does not reliably
875 state host is down or not. This might cause same server instance to run twice
876 if action taken to evacuate instance to another host.
877 * Nova state for server(s) on failed host will not change, but remains active
878 and running. This gives the user false information about server state.
879 * VIM northbound interface notification of host faults towards VNFM and NFVO
880 should be in line with OpenStack state. This fault notification is a Telco
881 requirement defined in ETSI and will be implemented by OPNFV Doctor project.
882 * Openstack user cannot make HA actions fast and reliably by trusting server
883 state and host state.
887 There needs to be a new API for Admin to state host is down. This API is used to
888 mark services running in host down to reflect the real situation.
890 Example on compute node is:
892 * When compute node is up and running:::
894 vm_state: activeand power_state: running
895 nova-compute state: up status: enabled
897 * When compute node goes down and new API is called to state host is down:::
899 vm_state: stopped power_state: shutdown
900 nova-compute state: down status: enabled
904 There is no attractive alternative to detect all different host faults than to
905 have an external tool to detect different host faults. For this kind of tool to
906 exist there needs to be new API in Nova to report fault. Currently there must be
907 some kind of workarounds implemented as cannot trust or get the states from
908 OpenStack fast enough.
910 .. [*] https://blueprints.launchpad.net/nova/+spec/update-server-state-immediately
915 This section lists some BPs related to Doctor, but proposed by drafters outside
918 pacemaker-servicegroup-driver [*]_
919 __________________________________
921 This BP will detect and report host down quite fast to OpenStack. This however
922 might not work properly for example when management network has some problem and
923 host reported faulty while VM still running there. This might lead to launching
924 same VM instance twice causing problems. Also NB IF message needs fault reason
925 and for that the source needs to be a tool that detects different kind of faults
926 as Doctor will be doing. Also this BP might need enhancement to change server
927 and service states correctly.
929 .. [*] https://blueprints.launchpad.net/nova/+spec/pacemaker-servicegroup-driver