MongoDB replication set replica set (Master-slave Replication) (8)

Replicattion set is that multiple servers maintain the same copy of the data, increasing the availability of the server.

Replication Set Setup whole process

0: Create a directory

Mkdir-p/DATA/R0/DATA/R1/DATA/R2

1: Start 3 instances and declare instances to be part of a replication set

./bin/mongod--port 27017--dbpath/data/r0--smallfiles--replset RSA--fork--logpath/var/log/mongo17.log

./bin/mongod--port 27018--dbpath/data/r1--smallfiles--replset RSA--fork--logpath/var/log/mongo18.log

./bin/mongod--port 27019--dbpath/data/r2--smallfiles--replset RSA--fork--logpath/var/log/mongo19.log

2: Start Mongo.exe, feel free to connect to a server, start the configuration

Use admin

var rsconf = {

_id: ' RSA ',

Members

[

{

_id:0,

Host: ' 127.0.0.1:27017 '

},

{

_id:1,

Host: ' 127.0.0.1:27018 '

},

{

_id:2,

Host: ' 127.0.0.1:27019 '

}

]

}

3: Initialize according to configuration

Rs.initiate (rsconf);

4: View status

Rs.status ();

We got three nodes "Statestr": "Secondary", "statestr": "Secondary", "Statestr": "PRIMARY",

5: Add node

Rs.add (' 192.168.1.201:27018 ');

Rs.add (' 192.168.1.201:27019 ');

6: Delete node

Rs.remove (' 192.168.1.201:27019 ');

7: Primary Node inserts data

>use Test

>db.user.insert ({uid:1,name: ' Lily '});

8: Connection Secondary Query synchronization situation

./bin/mongo--port 27019

>use Test

>show collections;

Rsa:secondary> Show Collections;

2015-11-10t21:56:14.075+0800 E QUERY error:listdatabases failed:{"note": "

From ExecCommand "," OK ": 0," errmsg ":" Not Master "}

At Error (<anonymous>)

At Mongo.getdbs (src/mongo/shell/mongo.js:47:15)

At Shellhelper.show (src/mongo/shell/utils.js:630:33)

At Shellhelper (src/mongo/shell/utils.js:524:36)

At (SHELLHELP2): 1:1 at src/mongo/shell/mongo.js:47

8.1 The above error occurs because slave is not allowed to read and write by default

>rs.slaveok ();

>show collections;

See data that is consistent with primary

MongoDB replication set replica set (Master-slave Replication) (8)