Replication Setup and Configuration Guide

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Table of Contents

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opHA-MB 5.0 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 receives 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 Main Primary goes down the secondary primary will take over also if a poller goes down the mirror will take over.

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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)

1. Software Installation

1.1 Download Software

Download the required software onto each server.

1.2 Install Software

IMPORTANT: All the servers should be setup with the following

a. opHA 4 needs to be currently installed

b. Pollers and mirrors discovered by the Main - Primary

bc. Server names set

cd. Secondary Primary server setup as Primary

ce. One server needs to be an Arbiter. A poller can be used for this

cf. Mongo MongoDB 6 installed

In this setup guide we are using example server/host names so you will have to use the names that you have set for your own configurationWe will be using the below example host names throughout this guide.

You would replace with your own where applicable. For this example we have the required 6 servers for the setup.

IMPORTANT:

One server should be set as an Arbiter and in this example we are using Poller1 Server

Main - Primary Server: opha-dev1.opmantek.net

Poller1 Server: opha-dev2.opmantek.net [Arbiter Server]

Mirror1 Server: opha-dev3.opmantek.net

Poller2 Server: opha-dev4.opmantek.net

Mirror2 Server: opha-dev5.opmantek.net

Second - Primary: opha-dev6.opmantek.net

Run the installation commands on each server as needed.

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Code Block

language	json

sh ./opHA-Linux-x86_64-5.0.0.run

VERY IMPORTANT : During the installation of the arbiter server you must answer 'Nn' at the following prompt

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2. NATS Setup

This configuration should be applied to the Main - Primary, Arbiter, and Secondary Primary servers ONLY.

Edit Configuration: Update the /etc/nats-server.conf file with the following settings:

Code Block

language	json

server_name: "opha-dev1.opmantek.net"  #The local server  
http_port: 8222 
listen: 4222 
jetstream: enabled 
accounts { 
  $SYS { 
    users = [ 
      { user: "admin",
        pass: "password" 
      } 
    ] 
  } 
  ophad: { 
    users: [ 
        { user: "omkadmin", password: "op42opha42" } 
    ] 
    jetstream: enabled 
  } 
} 

jetstream { 
  store_dir: "/opt/nats/storage" 
  max_memory_store: 1028M 
  max_file_store: 1028M 
} 
cluster { 
  name: "C1" 
  host: "opha-dev1.opmantek.net"  #The current host 
  # the current server 
  listen: "0.0.0.0:6222" 
  routes: [ 
    # secondary primary
    "nats://opha-dev6.opmantek.net:6222" 
    # server with the arbiter 
    "nats://opha-dev2.opmantek.net:6222" 
    # other servers 
  ] 
}

3. Common Configuration for All Servers

3.1 Update `/usr/local/omk/conf/opCommon.json`

Backup Configuration: Make a backup copy of the opCommon.json file before making any changes.
Add NATS Cluster Configuration: Ensure the following configuration is included in opCommon.json on all servers. In the below example we have added the main-primaryMain Primary, arbiter and second-primary and Secondary Primary FQDNs and port/s to be utilized in the nats_cluster array under the “database“ json objectattribute, you can find this in the database section.
Code Block
language json
"nats_cluster": [ "opha-dev1.opmantek.net:4222", "opha-dev2.opmantek.net:4222", "opha-dev6.opmantek.net:4222" ]

4. Server-Specific Configuration

4.1 Update `/usr/local/omk/conf/opCommon.json` for Main

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Primary and Secondary Primary only

and Secondary Primary servers:

Code Block

language	json

"db_replica_set": "rs1", 
"db_mongo_cluster": [ "opha-dev1.opmantek.net", "opha-dev6.opmantek.net" ], 
"nats_num_replicas": 3, 
"nats_cluster": [ "opha-dev1.opmantek.net", "opha-dev2.opmantek.net", "opha-dev6.opmantek.net" ]

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5.

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Update License

To obtain a license please contact FirstWave Sales.

Currently there are 2 available licenses and messagebus Message Bus will not run without a license.

opHA-MB for NMIS & opCharts (This license is required for messagebus Message Bus to run)
1. NMIS and opCharts data are synced from all poller/mirrors to the Main Primary using Message Bus. In replication mode, if the Main Primary were to go down the Secondary Primary will retain the NMIS and opCharts data.
  Image Added
opHA-MB for opEvents (This license is an add-on for opEvents).
1. With this add-on opEvents will use MessageBus to sync opEvents data from each poller/mirror to the
main-primary
1. Main Primary and in replication mode opEvents data is synced to the
secondary-primary. If the main-primary
1. Secondary Primary. In replication mode, If the Main Primary were to go down the
secondary primary
1. Secondary Primary will retain the opEvents data.
  Image Modified

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You need to add your license to the opLicensing app as below on the main-primary and second-primary servers
Image Added

6. MongoDB Setup (Main

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Primary Only)

The following steps should be performed only on the Main - Primary MongoDB instance.

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6.1 Initialize MongoDB Replica Set

Connect to MongoDB using the mongosh command and configure the replica set:

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Code Block
mongosh --username opUserRW --password op42flow42 admin

Run the following commandAdd the main-primary and secondary-primary to the below command and run it

Code Block
rs.initiate({ _id: "rs1", version: 1, members: [ { _id: 0, host : "opha-dev1.opmantek.net:27017" }, { _id: 1, host : "opha-dev6.opmantek.net:27017" } ] })

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6.2 Set Default Write Concern

Run the following command to set the default write concern:

Code Block
db.adminCommand({ "setDefaultRWConcern": 1, "defaultWriteConcern": { "w": 1 } })

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6.3 Add Arbiter

Run the following command to add an arbiter to the replica set:

Code Block
rs.addArb("opha-dev2.opmantek.net:27018")

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6.4 Restart mongod on the Main

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Primary and Second

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Primary

Run the following command on the Main - Primary, Secondary Primary, and Arbiter servers ONLY:

Code Block
sudo systemctl restart mongod

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7. Starting Services

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7.1 Start NATS

Start the NATS service on the Main - Primary, Secondary Primary, and Arbiter servers ONLY:

Code Block
systemctl start nats-server

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7.2 Restart mongod on Pollers and Mirrors only

After configuration changes, restart mongod on all Mirrors and Pollers servers ONLY:

Code Block
systemctl restart mongod

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7.3 Restart services on all servers

After configuration changes have been made, restart the services on all the servers you will need to restart the relevant FirstWave module daemons applicable to your server.

For example if you have NMIS9, opCharts, opEvents and opHA 5 installed you would execute as follows:

Code Block
systemctl restart nmis9d opchartsd opeventsd omkd ophad

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7.4 Start the Poller and Mirrors

Execute the following command on the poller and mirror servers.

Code Block
cd /usr/local/omk/bin ./ophad cmd producer start

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8. Final Steps

Accept EULAs: Make sure when you login to each server to confirm that all End User License Agreements (EULAs) are accepted.

8. Switching Main and Secondary Primary Servers

To switch from Main-Primary to Secondary Primary, follow these steps:

Connect to MongoDB:

Code Block
mongosh --username opUserRW --password op42flow42 admin

Update member priorities:
Code Blockcfg = rs
.
conf() cfg.members[0].priority = 0.6 cfg.members[1].priority = 0.5 rs.reconfig(cfg)

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Versions Compared

Old Version 22

New Version Current

Key

Replication Setup and Configuration Guide

1. Software Installation

1.1 Download Software

1.2 Install Software

2. NATS Setup

3. Common Configuration for All Servers

3.1 Update `/usr/local/omk/conf/opCommon.json`

4. Server-Specific Configuration

4.1 Update `/usr/local/omk/conf/opCommon.json` for Main

Primary and Secondary Primary only

5.

Update License

6. MongoDB Setup (Main

Primary Only)

6.1 Initialize MongoDB Replica Set

6.2 Set Default Write Concern

6.3 Add Arbiter

6.4 Restart mongod on the Main

Primary and Second

Primary

7. Starting Services

7.1 Start NATS

7.2 Restart mongod on Pollers and Mirrors only

7.3 Restart services on all servers

7.4 Start the Poller and Mirrors

8. Final Steps

8. Switching Main and Secondary Primary Servers

Page Comparison

Versions Compared

Old Version 22

New Version Current

Key

Replication Setup and Configuration Guide

1. Software Installation

1.1 Download Software

1.2 Install Software

2. NATS Setup

3. Common Configuration for All Servers

3.1 Update /usr/local/omk/conf/opCommon.json

4. Server-Specific Configuration

4.1 Update /usr/local/omk/conf/opCommon.json for Main

Primary and Secondary Primary only

5.

Update License

6. MongoDB Setup (Main

Primary Only)

6.1 Initialize MongoDB Replica Set

6.2 Set Default Write Concern

6.3 Add Arbiter

6.4 Restart mongod on the Main

Primary and Second

Primary

7. Starting Services

7.1 Start NATS

7.2 Restart mongod on Pollers and Mirrors only

7.3 Restart services on all servers

7.4 Start the Poller and Mirrors

8. Final Steps

8. Switching Main and Secondary Primary Servers

3.1 Update `/usr/local/omk/conf/opCommon.json`

4.1 Update `/usr/local/omk/conf/opCommon.json` for Main