MongoDB Master-Slave architecture and replica set schema

Master-Slave architecture :

MongoDB supports the traditional Master-slave architecture. The master node is responsible for reading and writing data, and slave does not have write permissions. There is no automatic failover feature, you need to specify the master and slave side, and are not recommended for use in production.

Configuration of master-slave architecture

Environment: CentOS6.5 MongoDB3.4

Master configuration file

Master.conf

Dbpath=/data/mongo/masterlogpath=/var/log/mongo/master/mongodb.logport=27017bind_ip=127.0.0.1master=true fork= True//Background running MongoDB service

Slave configuration file

Dbpath=/data/mongo/slavelogpath=/var/log/mongo/slave/mongodb.logport=27018bind_ip=127.0.0.1slave=truefork=true Background run MongoDB service source=127.0.0.1:27017//Configuration master IP and port

Start master and slave, respectively

MONGO--config master.conf MONGO--config slave.conf

Log in master and slave separately

MONGO 127.0.0.1:27017mongo 127.0.0.1:27018

Perform show DBS on master

> Show Dbsadmin 0.000GBlocal 0.005GB

Show dbs error on slave

> Show dbs2018-04-19t11:31:35.982+0800 E QUERY [thread1] error:listdatabases failed:{"OK": 0, "errm SG ":" Not Master and Slaveok=false "," code ": 13435," codename ":" Notmasternoslaveok "}: [Email protected]/ Mongo/shell/utils.js:25:13[email Protected]/mongo/shell/mongo.js:62:1[email Protected]/mongo/shell/utils.js : 782:19[email protected]/mongo/shell/utils.js:672:15@ (SHELLHELP2): 1:1

This error is due to the default slave does not have read and write permissions on the slave can be executed on the following command to resolve

> Rs.slaveok ()//2.6 version setup method is different > show dbsadmin 0.000GBlocal 0.000GB

Test:

Create a database on the main library masterslavetest and create some test data

> Use masterslaveswitched to DB masterslave> for (i =; i < 100000; i++) {... db.users.insert ({... "I": I,... "UserName": "User" + I,... ... "Age": Math.floor (Math.random ()),... "Created": New Date (),... Total:Math.floor (Math.random () * +) * I ...}) ... } Writeresult ({"ninserted": 1})

perform each of the two instances the following command you can see that the data on the two databases is consistent, which is performed on the primary databaseCRUDand so on, the data from the library is still consistent with the main library

Db.users.find ()

Slave also executes the above command.

Test add a piece of data to the slave node to see

> Db.mycoll.insert ({"I": 9999, "username": "Test", "Age": ()) Writeresult ({"Writeerror": {"code": 10107, "errmsg": " Not Master "}})

You can see that the slave node does not have write permissions.

Turn off the MONGO process on master.

> show dbs2018-04-19t11:58:43.464+0800 e query     [thread1] Error: listDatabases failed:{          "OK"  : 0,         "errmsg"  :  "not"  master and slaveok=false ",        " code " :  13435,         "codename"  :  "Notmasternoslaveok"} :[ email protected]/mongo/shell/utils.js:25:13[email protected]/mongo/shell/mongo.js:62:1[email  protected]/mongo/shell/utils.js:782:19[email protected]/mongo/shell/utils.js:672:15@ (SHELLHELP2):1:1>  rs.slaveok () > > > show dbsadmin         0.000GBLOCAL        0.000GBMASTERSLAVE  0.005GB 

Slave still has no write permission

MongoDB Master-Slave architecture and replica set schema