Replication Setup and Configuration Guide
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opHA 5 introduces the concept of a Primary & multiple Poller servers and a message bus: (with replication)
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.
With Replication and Nats if the main-primary goes down the secondary primary will take over also if a poller goes down the mirror will take over.
Here are terms used in this project together with their meanings.
Term | Meaning |
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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) |
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1. Software Installation
1.1 Download Software
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