Introduction
opHA introduces the concept of a Primary & multiple Poller servers and a message bus:
The Primary is the server that keeps the information of all the pollers and it is where we can read all the information from. The Consumer (ophad running on Primary) reads data continuously off the message bus and stores it in the database
The Producer (ophad running on Pollers) has a change stream setup for the collections and recieves update from the database if there is any. This change stream data is pushed onto the message bus.
Here are terms used in this project together with their meanings.
Term | Meaning |
|---|---|
Main Primary | server instance running opHA with role = 'primary_master' |
Secondary Primary | server instance running opHA with role = 'master'. Also referred to as just 'primary'. |
Peer | server instance running opHA with role = 'poller' or 'mirror'. It can optionally be of type 'streaming' which means that it is linked to an ophad instance. |
Poller | server instance running opHA with role = 'poller' |
Mirror | server instance running opHA with role = 'mirror'. It is paired with a poller and polls the same devices as that poller, however its data is not sync'd with primary unless the poller is offline. |
Producer | an instance of the ophad process running in 'producer' mode (as per configuration). This will typically be running on the same server instances as the primary. |
Consumer | an instance of the ophad process running in 'consumer' mode (as per configuration). This will typically be running on the same server instance as the poller (or mirror) |
Installation instruction:
opHA 5 Installation (Replication)
Releases
opHA Message Bus 5.0.0
RELEASED 8 November 2024
New release, installation guide to setup/license FirstWave opHA 5.0.0 (opHA Message Bus).
The new opHA 5.0.0 features includes
Installer and the installation guide to setup opHAMB in non replicated mode. In a non replicated mode is when the setup has a single Main Primary. A single instance of NATS service and a single instance of Mongodb is run on the Main Primary.
Installer and the installation guide to setup opHAMB in a replicated mode. In a replicated mode both Mongodb on Primary and Nats needs to be replicated. To this end the installer sets up have a Main Primary and atleast one Secondary Primary.
There instances of NATS is needed to be run to tolerate a one node failure. Main Primary and Secondary Primary runs on instance of NATS each. A Poller can be used to run the third instance.
Like wise Mongodb is run as a primary mongodb instance on Main Primary. Secondary Primary runs a replica as a secondary mongodb instance. The third instance of mongodb is run as an arbiter and can be run on one of the Poller where NATS is run.