Replication Setup and Configuration Guide
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Table of Contents | ||
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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
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VERY IMPORTANT : During the installation of the arbiter server you must answer 'N' 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 ] }
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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-primary, arbiter and second-primary in the nats_cluster array under the “database“ json objectCode Block language json "nats_cluster": [ "opha-dev1.opmantek.net:4222", "opha-dev2.opmantek.net:4222", "opha-dev6.opmantek.net:4222" ]
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4. Server-Specific Configuration
4.1 Update /usr/local/omk/conf/opCommon.json
for Main-Primary and Secondary Primary only
and Secondary Primary servers:
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"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" ] |
4.2 Update License
Currently there are 2 available licenses and messagebus will not run without a license.
opHA-MB for NMIS & opCharts (This license is required for messagebus to run)
opHA-MB for opEvents (This license is an add-on for opEvents)
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5. MongoDB Setup (Main-Primary Only)
The following steps should be performed only on the Main-Primary MongoDB instance.
5.1 Initialize MongoDB Replica Set
Connect to MongoDB using the mongosh
command and configure the replica set:
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Code Block |
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rs.initiate({ _id: "rs1", version: 1, members: [ { _id: 0, host : "opha-dev1.opmantek.net:27017" }, { _id: 1, host : "opha-dev6.opmantek.net:27017" } ] }) |
5.2 Set Default Write Concern
Run the following command to set the default write concern:
Code Block |
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db.adminCommand({ "setDefaultRWConcern": 1, "defaultWriteConcern": { "w": 1 } }) |
5.3 Add Arbiter
Run the following command to add an arbiter to the replica set:
Code Block |
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rs.addArb("opha-dev2.opmantek.net:27018") |
5.4 Restart mongod on the Main-Primary and Second-Primary
Run the following command on the Main-Primary, Secondary Primary, and Arbiter servers ONLY:
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sudo systemctl restart mongod |
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6. Starting Services
6.1 Start NATS
Start the NATS service on the Main-Primary, Secondary Primary, and Arbiter servers ONLY:
Code Block |
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systemctl start nats-server |
6.2 Restart mongod on Pollers and Mirrors only
After configuration changes, restart mongod on all Mirrors and Pollers servers ONLY :
Code Block |
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systemctl restart mongod |
6.3 Restart services on all servers
After configuration changes, restart the services on all the servers :
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systemctl restart nmis9d opchartsd opeventsd omkd ophad |
6.4 Start the Poller and Mirrors
Execute the following command on the poller and mirror servers.
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cd /usr/local/omk/bin ./ophad cmd producer start |
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7. Final Steps
Accept EULAs: Make sure when you login to each server to confirm that all End User License Agreements (EULAs) are accepted.
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8. Switching Main and Secondary Primary Servers
To switch from Main-Primary to Secondary Primary, follow these steps:
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