.. Dashboard V3 documentation master file, created by
   sphinx-quickstart on Tue Dec  8 20:15:49 2020.
   You can adapt this file completely to your liking, but it should at least
   contain the root `toctree` directive.

Provisioning and HA
===================

All Dashboard components are designed to have
some level of redundancy and resiliency.

.. contents:: :local:

Overall Provisioning Overview
-----------------------------

.. uml::

   rectangle prod-noc-alarms01.geant.org {
      component "Collector" as COL1
      component "Classifier" as CLA1
      component "Archiver" as ARC1
      component "Correlator" as COR1
      queue "RabbitMQ node" as RMQ1
      database "MariaDB node" as SQL1
      database "Redis node" as Redis1
   }

   rectangle prod-noc-alarms02.geant.org {
      component "Collector" as COL2
      component "Classifier" as CLA2
      component "Archiver" as ARC2
      component "Correlator" as COR2
      queue "RabbitMQ node" as RMQ2
      database "MariaDB node" as SQL2
      database "Redis node" as Redis2
   }

   rectangle prod-noc-alarms03.geant.org {
      component "Collector" as COL3
      component "Classifier" as CLA3
      component "Archiver" as ARC3
      component "Correlator" as COR3
      queue "RabbitMQ node" as RMQ3
      database "MariaDB node" as SQL3
      database "Redis node" as Redis3
   }

   COL1 <--> COL2
   COL2 <--> COL3
   COR1 <--> COR2
   COR2 <--> COR3
   RMQ1 <--> RMQ2
   RMQ2 <--> RMQ3
   SQL1 <--> SQL2
   SQL2 <--> SQL3
   Redis1 <--> Redis2
   Redis2 <--> Redis3


Data Processing Pipeline
-----------------------------

The system is composed of several processes
that communicate with each other via a RabbitMQ
queue broker.

The basic RabbitMQ pipeline is shown below:

TODO: throw out the 2nd diagram, kept for now
as an example.  1st diagram is the newer syntax


.. uml::

   start
   note right
     SNMP traps
     from NE's
   end note

   fork
     #lightgreen:Collector-01;
     note right: leader
   fork again
     :Collector-02;
   fork again
     :Collector-03;
   end fork

   :broker}
   note right
     dashboard.collection
     exchange
   end note

   split
      fork
        :Classifier-01;
      fork again
        :Classifier-02;
      fork again
        :Classifier-03;
      end fork

      :broker}
      note right
        dashboard.classified
        exchange
      end note

      fork
        #lightgreen:Correlator-01;
        note right: leader
      fork again
        #lightgrey:Correlator-02;
      fork again
        #lightgrey:Correlator-03;
         note right
            followers don't
            consume messages
         end note
      end fork

      :broker}
      note right
        dashboard.external.notifications
        exchange
      end note

      fork
        :TTS Notifier-01;
      fork again
        :TTS Notifier-02;
      fork again
        :TTS Notifier-03;
      end fork

      :Email Server;
      stop

   split again

      fork
        :Archiver-01;
      fork again
        :Archiver-02;
      fork again
        :Archiver-03;
      end fork

      :ElasticSearch;
      stop

   end split

.. uml::

   "NE #1" --> ===SNMP===
   "NE #2" --> ===SNMP===
   "NE #3" --> ===SNMP===
   "NE #4" --> ===SNMP===
   "..." --> ===SNMP===

   ===SNMP=== --> "Collector-01"
   ===SNMP=== --> "Collector-02"
   ===SNMP=== --> "Collector-03"

   "Collector-01" --> ===TRAPS===
   "Collector-02" --> ===TRAPS===
   "Collector-03" --> ===TRAPS===

   ===TRAPS=== --> "Classifier-01"
   ===TRAPS=== --> "Classifier-02"
   ===TRAPS=== --> "Classifier-03"
   ===TRAPS=== --> "Archiver-01"
   ===TRAPS=== --> "Archiver-02"
   ===TRAPS=== --> "Archiver-03"

   "Classifier-01" --> ===CLASSIFIED===
   "Classifier-02" --> ===CLASSIFIED===
   "Classifier-03" --> ===CLASSIFIED===

   ===CLASSIFIED=== --> "Correlator-01"
   ===CLASSIFIED=== --> "Correlator-02"
   ===CLASSIFIED=== --> "Correlator-03"

   "Correlator-01" --> ===MESSAGES===

   ===MESSAGES=== --> "tts notifier-01"
   ===MESSAGES=== --> "tts notifier-02"
   ===MESSAGES=== --> "tts notifier-03"


RabbitMQ
----------

A RabbitMQ cluster is provisioned across all 3 nodes, with mirroring of all
queues.

.. uml::

   node "RabbitMQ 01" as RMQ1 {
     rectangle "exchanges" as EX1 #lightgreen
     rectangle "dashboard* queues" as Q1 #lightblue
   }

   node "RabbitMQ 02" as RMQ2 {
     rectangle "exchanges" as EX2 #lightgreen
     rectangle "dashboard* queues" as Q2 #lightblue
   }

   node "RabbitMQ 03" as RMQ3 {
     rectangle "exchanges" as EX3 #lightgreen
     rectangle "dashboard* queues" as Q3 #lightblue
   }

   EX1 <..> EX2 : "mirroring"
   EX2 <..> EX3 : "mirroring"
   Q1 <..> Q2 : "mirroring"
   Q2 <..> Q3 : "mirroring"

   note as N1
       Modern api's support randomized
       server selection and automatic
       iteration until an available host
       is found
   end note

   'center
   RMQ2 -[hidden]right--> N1


Galera Cluster
------------------

Alarms are stored in a MariaDB Galera cluster.
This is the interface between the backend
processing provided by this project and the GUI.

The Galera cluster is provisioned something like this:

.. uml::

   cloud Galera as "Galera Cluster"  {
     database MDB1 as "MariaDB-01"
     database MDB2 as "MariaDB-02"
     database MDB3 as "MariaDB-03"
   }


   node HAProxy
   HAProxy -up--> MDB1
   HAProxy -up--> MDB2
   HAProxy -up--> MDB3

   node client as "mysql client"
   client -up--> HAProxy


Inventory Provider and Redis
------------------------------

The dashboard servers are provisioned with a Redis cluster, which
is the backend of the Inventory Provider rather than being accessed
directly by dashboard components.

.. uml::

   collections Redis as "Redis Cluster"
   collections Sentinel as "Sentinel Group"
   node "Inventory Provider 01" as IV1 #lightgreen
   node "Inventory Provider 02" as IV2 #lightgreen
   node HAProxy
   node classifier as "classifier(s)" #lightgreen

   HAProxy --> IV1
   HAProxy --> IV2
   classifier --> HAProxy
   IV1 --> Sentinel
   IV2 --> Sentinel
   Sentinel --> Redis