Kenneth的部落格

HOMEWORK: HOMEWORK 6.5

In this homework you will build a small replica set on your own computer. We will check that it works with validate.py, which you should download from the Download Handout link. 

Create three directories for the three mongod processes. On unix, this could be done as follows:

mkdir -p /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.

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: Omit -p from mkdir. Also omit --fork and use start mongod with Windows compatible paths (i.e. backslashes "\") for the --dbpath argument (e.g;C:\data\rs1). 

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. 

Now run validate.py to confirm that it works.

python validate.py

Validate connects to your local replica set and checks that it has three nodes. It has been tested under Pymongo 2.3 and 2.4. Type the validation code below.

因為我是在windows環境下做功課，所以有些困難的。在做作業之前，要先把default mongodb server關掉，然後一一的執行下列指定。

start mongod --replSet m101 --logpath "1.log" --dbpath \data\rs1 --port 27017 --smallfiles --oplogSize 64

start mongod --replSet m101 --logpath "2.log" --dbpath C:\data\rs2 --port 27018 --smallfiles --oplogSize 64

start mongod --replSet m101 --logpath "3.log" --dbpath C:\data\rs3 --port 27019 --smallfiles --oplogSize 64

每執行一次，就會跳出一個視窗，所以一共跳出三個視窗。

所接著就依作業中執行下列指令

mongo --port 27017

config = { _id: "m101", members:[
          { _id : 0, host : "localhost:27017"},
          { _id : 1, host : "localhost:27018"},
          { _id : 2, host : "localhost:27019"} ]
};

rs.initiate(config);

 最後回到command line 執行 validate.py來驗證

python validate.py