building MongoDB small replica set
In this homework you will build a small replica set on your own computer. We will check that it works with MongoProc.
Create three directories for the three mongod processes. On unix, this could be done as follows:
mkdir -p /data/rs1 /data/rs2 /data/rs3
or on Windows:
mkdir \data\rs1 \data\rs2 \data\rs3
Now start three mongo instances as follows. Note that are three commands. The browser is probably wrapping them visually.
Linux and Mac users:
mongod --replSet m101 --logpath "1.log" --dbpath /data/rs1 --port 27017 --smallfiles --oplogSize 64 --fork
mongod --replSet m101 --logpath "2.log" --dbpath /data/rs2 --port 27018 --smallfiles --oplogSize 64 --fork
mongod --replSet m101 --logpath "3.log" --dbpath /data/rs3 --port 27019 --smallfiles --oplogSize 64 --fork
Windows users:
start mongod --replSet m101 --logpath 1.log --dbpath \data\rs1 --port 27017 --smallfiles --oplogSize 64
start mongod --replSet m101 --logpath 2.log --dbpath \data\rs2 --port 27018 --smallfiles --oplogSize 64
start mongod --replSet m101 --logpath 3.log --dbpath \data\rs3 --port 27019 --smallfiles --oplogSize 64
Now connect to a mongo shell and make sure it comes up.
mongo --port 27017
Now you will create the replica set. Type the following commands into the mongo shell:
config = { _id: "m101", members:[
{ _id : 0, host : "localhost:27017"},
{ _id : 1, host : "localhost:27018"},
{ _id : 2, host : "localhost:27019"} ]
};
rs.initiate(config);
At this point, the replica set should be coming up. You can type
rs.status()
to see the state of replication.