MongoDB Replica Set

MongoDB Replica Set

• Earlier versions used Master-slave, a master one from and MySQL similar, but slave in this architecture is read-only, when the main library down, from the library can not automatically switch to primary
• The Master-slave mode has now been phased out, changed to a replica set, this mode has a master (primary), and multiple Slave (secondary), read-only. Support to set weights for them, when the main outage, the most weighted from the switch-based.
• In this architecture, you can also establish a quorum (arbiter) role, which is only responsible for adjudication, not storing data
• In this architecture, read and write data are in the Lord, in order to achieve the purpose of load balancing needs to manually specify the target server read library

MongoDB Replica Set Build

• Three machines: 192.168.221.10 (secondary) 192.168.221.20 (primary) 192.168.221.30 (secondary), all installed mongodb-org
• Edit profile (remove user authentication)

  vim /etc/mongod.conf  //加上以下三行replication:oplogSizeMB: 20replSetName: apenglinuxsystemctl restart mongod.service

MongoDB Replica Set