Overview
This guide will show you how to convert MongoDB to to a Replica Set.
Step 1 : Stop the MongoDB Instance.
systemctl stop mongodStep 2 : Modify the MongoDB Configuration File and add the below content to config file located at /etc/mongod.conf.
replication:
replSetName: "rs0"
security:
keyFile: /usr/local/apps/mongodb/etc/mongodb-keyfileExecute the below command to generate keyFile:
openssl rand -base64 756 > /usr/local/apps/mongodb/etc/mongodb-keyfile
chown mongod:mongod /usr/local/apps/mongodb/etc/mongodb-keyfile
chmod 600 /usr/local/apps/mongodb/etc/mongodb-keyfile
rm -rf /tmp/mongodb-27017.sockStep 3 : Start the MongoDB Instance.
systemctl start mongodStep 4 : Execute the following command to login as admin and authenticate in mongodb shell.
mongosh
use admin
db.auth('root', 'password')Note : Get MongoDB password from /var/webuzo/mongodb.conf
Step 5 : Initiate the Replica Set, execute the following command.
rs.initiate()Step 6 : Verify the Replica Set Status
rs.status()Expected output will be the following.
rs0 [direct: other] admin> rs.status()
{
set: 'rs0',
date: ISODate('2024-05-27T12:13:15.252Z'),
myState: 1,
term: Long('1'),
syncSourceHost: '',
syncSourceId: -1,
heartbeatIntervalMillis: Long('2000'),
majorityVoteCount: 1,
writeMajorityCount: 1,
votingMembersCount: 1,
writableVotingMembersCount: 1,
optimes: {
lastCommittedOpTime: { ts: Timestamp({ t: 1716811990, i: 1 }), t: Long('1') },
lastCommittedWallTime: ISODate('2024-05-27T12:13:10.299Z'),
readConcernMajorityOpTime: { ts: Timestamp({ t: 1716811990, i: 1 }), t: Long('1') },
appliedOpTime: { ts: Timestamp({ t: 1716811990, i: 1 }), t: Long('1') },
durableOpTime: { ts: Timestamp({ t: 1716811990, i: 1 }), t: Long('1') },
lastAppliedWallTime: ISODate('2024-05-27T12:13:10.299Z'),
lastDurableWallTime: ISODate('2024-05-27T12:13:10.299Z')
},
lastStableRecoveryTimestamp: Timestamp({ t: 1716811940, i: 1 }),
electionCandidateMetrics: {
lastElectionReason: 'electionTimeout',
lastElectionDate: ISODate('2024-05-27T12:11:28.340Z'),
electionTerm: Long('1'),
lastCommittedOpTimeAtElection: { ts: Timestamp({ t: 1716811885, i: 1 }), t: Long('-1') },
lastSeenOpTimeAtElection: { ts: Timestamp({ t: 1716811885, i: 1 }), t: Long('-1') },
numVotesNeeded: 1,
priorityAtElection: 1,
electionTimeoutMillis: Long('10000'),
newTermStartDate: ISODate('2024-05-27T12:11:29.061Z'),
wMajorityWriteAvailabilityDate: ISODate('2024-05-27T12:11:30.326Z')
},
members: [
{
_id: 0,
name: '127.0.0.1:27017',
health: 1,
state: 1,
stateStr: 'PRIMARY',
uptime: 550,
optime: { ts: Timestamp({ t: 1716811990, i: 1 }), t: Long('1') },
optimeDate: ISODate('2024-05-27T12:13:10.000Z'),
lastAppliedWallTime: ISODate('2024-05-27T12:13:10.299Z'),
lastDurableWallTime: ISODate('2024-05-27T12:13:10.299Z'),
syncSourceHost: '',
syncSourceId: -1,
infoMessage: 'Could not find member to sync from',
electionTime: Timestamp({ t: 1716811888, i: 1 }),
electionDate: ISODate('2024-05-27T12:11:28.000Z'),
configVersion: 1,
configTerm: 1,
self: true,
lastHeartbeatMessage: ''
}
],
ok: 1,
'$clusterTime': {
clusterTime: Timestamp({ t: 1716811990, i: 1 }),
signature: {
hash: Binary.createFromBase64('qAbaBIhv7Uu5hTsqz280+jjxnl8=', 0),
keyId: Long('7373650916638982145')
}
},
operationTime: Timestamp({ t: 1716811990, i: 1 })
}
rs0 [direct: primary] admin>That's it now your MongoDB is configures as replica Set