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Diffstat (limited to 'docs/development/requirements')
| -rw-r--r-- | docs/development/requirements/05-implementation.rst | 162 |
1 files changed, 49 insertions, 113 deletions
diff --git a/docs/development/requirements/05-implementation.rst b/docs/development/requirements/05-implementation.rst index 84979772..7d168f6e 100644 --- a/docs/development/requirements/05-implementation.rst +++ b/docs/development/requirements/05-implementation.rst @@ -204,7 +204,7 @@ b) Response to the query request with information about the current state of :name: figure10 :width: 100% - NFVI Maintenance implementation plan + NFVI Maintenance scenario :numref:`figure10` shows a more detailed message flow (Steps 3 to 6 and 9) between the 4 building blocks introduced in Section 5.1.. @@ -229,77 +229,6 @@ between the 4 building blocks introduced in Section 5.1.. been freed. - -Implementation plan for OPNFV Release 1 ---------------------------------------- - -Fault management -^^^^^^^^^^^^^^^^ - -:numref:`figure11` shows the implementation plan based on OpenStack and -related components as planned for Release 1. Hereby, the Monitor can be realized -by Zabbix. The Controller is realized by OpenStack Nova [NOVA]_, Neutron -[NEUT]_, and Cinder [CIND]_ for compute, network, and storage, -respectively. The Inspector can be realized by Monasca [MONA]_ or a simple -script querying Nova in order to map between physical and virtual resources. The -Notifier will be realized by Ceilometer [CEIL]_ receiving failure events -on its notification bus. - -:numref:`figure12` shows the inner-workings of Ceilometer. After receiving -an "event" on its notification bus, first a notification agent will grab the -event and send a "notification" to the Collector. The collector writes the -notifications received to the Ceilometer databases. - -In the existing Ceilometer implementation, an alarm evaluator is periodically -polling those databases through the APIs provided. If it finds new alarms, it -will evaluate them based on the pre-defined alarm configuration, and depending -on the configuration, it will hand a message to the Alarm Notifier, which in -turn will send the alarm message northbound to the Consumer. :numref:`figure12` -also shows an optimized work flow for Ceilometer with the goal to -reduce the delay for fault notifications to the Consumer. The approach is to -implement a new notification agent (called "publisher" in Ceilometer -terminology) which is directly sending the alarm through the "Notification Bus" -to a new "Notification-driven Alarm Evaluator (NAE)" (see Sections 5.6.2 and -5.6.3), thereby bypassing the Collector and avoiding the additional delay of the -existing polling-based alarm evaluator. The NAE is similar to the OpenStack -"Alarm Evaluator", but is triggered by incoming notifications instead of -periodically polling the OpenStack "Alarms" database for new alarms. The -Ceilometer "Alarms" database can hold three states: "normal", "insufficient -data", and "fired". It is representing a persistent alarm database. In order to -realize the Doctor requirements, we need to define new "meters" in the database -(see Section 5.6.1). - -.. figure:: images/figure11.png - :name: figure11 - :width: 100% - - Implementation plan in OpenStack (OPNFV Release 1 ”Arno”) - - -.. figure:: images/figure12.png - :name: figure12 - :width: 100% - - Implementation plan in Ceilometer architecture - - -NFVI Maintenance -^^^^^^^^^^^^^^^^ - -For NFVI Maintenance, a quite similar implementation plan exists. Instead of a -raw fault being observed by the Monitor, the Administrator is sending a -Maintenance Request through the northbound interface towards the Controller -residing in the VIM. Similar to the Fault Management use case, the Controller -(in our case OpenStack Nova) will send a maintenance event to the Notifier (i.e. -Ceilometer in our implementation). Within Ceilometer, the same workflow as -described in the previous section applies. In addition, the Controller(s) will -take appropriate actions to evacuate the physical machines in order to prepare -them for the planned maintenance operation. After the physical machines are -emptied, the Controller will inform the Administrator that it can initiate the -maintenance. Alternatively the VMs can just be shut down and boot up on the -same host after maintenance is over. There needs to be policy for administrator -to know the plan for VMs in maintenance. - Information elements -------------------- @@ -889,55 +818,62 @@ Event Publisher for Alarm (Ceilometer) [*]_ **Problem statement:** - The existing "Alarm Evaluator" in OpenStack Ceilometer is periodically - querying/polling the databases in order to check all alarms independently from - other processes. This is adding additional delay to the fault notification - send to the Consumer, whereas one requirement of Doctor is to react on faults - as fast as possible. - - The existing message flow is shown in :numref:`figure12`: after receiving - an "event", a "notification agent" (i.e. "event publisher") will send a - "notification" to a "Collector". The "collector" is collecting the - notifications and is updating the Ceilometer "Meter" database that is storing - information about the "sample" which is capured from original "event". The - "Alarm Evaluator" is periodically polling this databases then querying "Meter" - database based on each alarm configuration. - - In the current Ceilometer implementation, there is no possibility to directly - trigger the "Alarm Evaluator" when a new "event" was received, but the "Alarm - Evaluator" will only find out that requires firing new notification to the - Consumer when polling the database. +The existing "Alarm Evaluator" in OpenStack Ceilometer is periodically +querying/polling the databases in order to check all alarms independently from +other processes. This is adding additional delay to the fault notification +send to the Consumer, whereas one requirement of Doctor is to react on faults +as fast as possible. + +The existing message flow is shown in :numref:`figure12`: after receiving +an "event", a "notification agent" (i.e. "event publisher") will send a +"notification" to a "Collector". The "collector" is collecting the +notifications and is updating the Ceilometer "Meter" database that is storing +information about the "sample" which is capured from original "event". The +"Alarm Evaluator" is periodically polling this databases then querying "Meter" +database based on each alarm configuration. + +.. figure:: images/figure12.png + :name: figure12 + :width: 100% + + Implementation plan in Ceilometer architecture + +In the current Ceilometer implementation, there is no possibility to directly +trigger the "Alarm Evaluator" when a new "event" was received, but the "Alarm +Evaluator" will only find out that requires firing new notification to the +Consumer when polling the database. **Change/feature request:** - This BP proposes to add a new "event publisher for alarm", which is bypassing - several steps in Ceilometer in order to avoid the polling-based approach of - the existing Alarm Evaluator that makes notification slow to users. +This BP proposes to add a new "event publisher for alarm", which is bypassing +several steps in Ceilometer in order to avoid the polling-based approach of +the existing Alarm Evaluator that makes notification slow to users. See +:numref:`figure12`. - After receiving an "(alarm) event" by listening on the Ceilometer message - queue ("notification bus"), the new "event publisher for alarm" immediately - hands a "notification" about this event to a new Ceilometer component - "Notification-driven alarm evaluator" proposed in the other BP (see Section - 5.6.3). +After receiving an "(alarm) event" by listening on the Ceilometer message +queue ("notification bus"), the new "event publisher for alarm" immediately +hands a "notification" about this event to a new Ceilometer component +"Notification-driven alarm evaluator" proposed in the other BP (see Section +5.6.3). - Note, the term "publisher" refers to an entity in the Ceilometer architecture - (it is a "notification agent"). It offers the capability to provide - notifications to other services outside of Ceilometer, but it is also used to - deliver notifications to other Ceilometer components (e.g. the "Collectors") - via the Ceilometer "notification bus". +Note, the term "publisher" refers to an entity in the Ceilometer architecture +(it is a "notification agent"). It offers the capability to provide +notifications to other services outside of Ceilometer, but it is also used to +deliver notifications to other Ceilometer components (e.g. the "Collectors") +via the Ceilometer "notification bus". **Implementation detail** - * "Event publisher for alarm" is part of Ceilometer - * The standard AMQP message queue is used with a new topic string. - * No new interfaces have to be added to Ceilometer. - * "Event publisher for Alarm" can be configured by the Administrator of - Ceilometer to be used as "Notification Agent" in addition to the existing - "Notifier" - * Existing alarm mechanisms of Ceilometer can be used allowing users to - configure how to distribute the "notifications" transformed from "events", - e.g. there is an option whether an ongoing alarm is re-issued or not - ("repeat_actions"). +* "Event publisher for alarm" is part of Ceilometer +* The standard AMQP message queue is used with a new topic string. +* No new interfaces have to be added to Ceilometer. +* "Event publisher for Alarm" can be configured by the Administrator of + Ceilometer to be used as "Notification Agent" in addition to the existing + "Notifier" +* Existing alarm mechanisms of Ceilometer can be used allowing users to + configure how to distribute the "notifications" transformed from "events", + e.g. there is an option whether an ongoing alarm is re-issued or not + ("repeat_actions"). .. [*] https://etherpad.opnfv.org/p/doctor_bps |