- Published on
Setup a Local MongoDB Development 3 Member Replica Set
- Authors
- Name
- Ruan Bekker
- @ruanbekker
Setup a Development Environment of a MongoDB Replica Set consisting of 3 mongod MongoDB Instances.
This is purely aimed for a testing or development environment, as one of the key points is that security is disabled, and that for this post, all 3 instances will be running on the same node.
Resources:
- https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/
- https://docs.mongodb.com/manual/tutorial/deploy-replica-set-for-testing/
Installation:
I am using Ubuntu 16.04, for other distributions, have a look at MongoDBs Installation Page
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
$ echo "deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
$ apt update
$ apt install -y mongodb-org -y
Prepare Directories:
Prepare the data directories, and as I am planning to use the --fork option, I need to specify the the --logpath, so therefore I will create the log directories as well:
$ mkdir -p /srv/mongodb/rs0-0 /srv/mongodb/rs0-1 /srv/mongodb/rs0-2
$ mkdir -p /var/log/mongodb/rs0-0 /var/log/mongodb/rs0-1 /var/log/mongodb/rs0-2
Run 3 MongoDB Instances:
Create 3 MongoDB Instances, each instance listening on it's unique port.
From MongoDB's Documentation:
"The --smallfiles and --oplogSize settings reduce the disk space that each mongod instance uses"
$ mongod --port 27017 --dbpath /srv/mongodb/rs0-0 --replSet rs0 --smallfiles --oplogSize 128 --logpath /var/log/mongodb/rs0-0/server.log --fork
$ mongod --port 27018 --dbpath /srv/mongodb/rs0-1 --replSet rs0 --smallfiles --oplogSize 128 --logpath /var/log/mongodb/rs0-1/server.log --fork
$ mongod --port 27019 --dbpath /srv/mongodb/rs0-2 --replSet rs0 --smallfiles --oplogSize 128 --logpath /var/log/mongodb/rs0-2/server.log --fork
Cofirm:
Confirm that the processes are listening on the ports that we defined:
$ netstat -tulpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN 1100/mongod
tcp 0 0 0.0.0.0:27018 0.0.0.0:* LISTEN 1127/mongod
tcp 0 0 0.0.0.0:27019 0.0.0.0:* LISTEN 1154/mongod
Connect to the first MongoDB Instnace:
Connect to our first MongoDB Instance, where we will setup the replica set:
$ mongo --port 27017
\>
Create the Replica Set Configuration Object:
> rsconf = {
_id: "rs0",
members: [
{
_id: 0,
host: "10.78.1.24:27017"
}
]
}
Initiate the replica set configuration:
> rs.initiate( rsconf )
{ "ok" : 1 }
Display the Replica Configuration with rs.conf():
rs0:SECONDARY> rs.conf()
{
"_id" : "rs0",
"version" : 1,
"protocolVersion" : NumberLong(1),
"members" : [
{
"_id" : 0,
"host" : "10.78.1.24:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : 60000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("59a2339f5ff27709a1645d28")
}
}
Add the other two mongodb instances to the replica set using rs.add():
rs0:PRIMARY> rs.add("10.78.1.24:27018")
{ "ok" : 1 }
rs0:PRIMARY> rs.add("10.78.1.24:27019")
{ "ok" : 1 }
View the status of our MongoDB Replica Set with rs.status():
rs0:PRIMARY> rs.status()
{
"set" : "rs0",
"date" : ISODate("2017-08-27T02:52:08.106Z"),
"myState" : 1,
"term" : NumberLong(1),
"heartbeatIntervalMillis" : NumberLong(2000),
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"appliedOpTime" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"durableOpTime" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
}
},
"members" : [
{
"_id" : 0,
"name" : "10.78.1.24:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 890,
"optime" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2017-08-27T02:51:56Z"),
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(1503802272, 1),
"electionDate" : ISODate("2017-08-27T02:51:12Z"),
"configVersion" : 3,
"self" : true
},
{
"_id" : 1,
"name" : "10.78.1.24:27018",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 16,
"optime" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2017-08-27T02:51:56Z"),
"optimeDurableDate" : ISODate("2017-08-27T02:51:56Z"),
"lastHeartbeat" : ISODate("2017-08-27T02:52:06.638Z"),
"lastHeartbeatRecv" : ISODate("2017-08-27T02:52:07.638Z"),
"pingMs" : NumberLong(0),
"syncingTo" : "10.78.1.24:27017",
"configVersion" : 3
},
{
"_id" : 2,
"name" : "10.78.1.24:27019",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 11,
"optime" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1503802316, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2017-08-27T02:51:56Z"),
"optimeDurableDate" : ISODate("2017-08-27T02:51:56Z"),
"lastHeartbeat" : ISODate("2017-08-27T02:52:06.638Z"),
"lastHeartbeatRecv" : ISODate("2017-08-27T02:52:07.241Z"),
"pingMs" : NumberLong(0),
"configVersion" : 3
}
],
"ok" : 1
}
Write some Data to MongoDB:
Create a Database named mydb:
rs0:PRIMARY> use mydb
switched to db mydb
Create a Collection, named mycol1:
rs0:PRIMARY> db.createCollection("mycol1")
{ "ok" : 1 }
rs0:PRIMARY> show collections
mycol1
Write 2 documents with:
- Name: James, Home Address: Country => South Africa, City => Cape Town
- Name: Frank, Home Address: Country => Ireland, City => Dublin
Write some data:
rs0:PRIMARY> db.mycol1.insert({"name": "james", "home address": {"country": "south africa", "city": "cape town"}})
WriteResult({ "nInserted" : 1 })
rs0:PRIMARY> db.mycol1.insert({"name": "frank", "home address": {"country": "ireland", "city": "dublin"}})
WriteResult({ "nInserted" : 1 })
Count all Documents in our Database:
rs0:PRIMARY> db.mycol1.find().count()
2
Scan through all documents, and show the in pretty print:
rs0:PRIMARY> db.mycol1.find().pretty()
{
"_id" : ObjectId("59a23d26c0c3824694f79ff6"),
"name" : "james",
"home address" : {
"country" : "south africa",
"city" : "cape town"
}
}
{
"_id" : ObjectId("59a23dbdc0c3824694f79ff7"),
"name" : "frank",
"home address" : {
"country" : "ireland",
"city" : "dublin"
}
}
Find Information about Frank:
rs0:PRIMARY> db.mycol1.find({"name": "frank"})
{ "_id" : ObjectId("59a23dbdc0c3824694f79ff7"), "name" : "frank", "home address" : { "country" : "ireland", "city" : "dublin" } }
Delete the Database, but confirm which database your are logged on, the delete using dropDatabase():
rs0:PRIMARY> db
mydb
rs0:PRIMARY> db.dropDatabase()
{ "dropped" : "mydb", "ok" : 1 }
rs0:PRIMARY> exit
bye