Overview of each node of the MongoDB replica set

By default: The primary node is responsible for data read and write, the secondary node backs up the data on the primary node, but the arbiter node

Data is not synchronized from the primary node

Arbiter Effect:

When the primary node fails, it can select a primary node from the second node and will not participate in the data read and write.

MongoDB uses oplog.rs to synchronize data sets between replication sets.

This article is from the DBA Sky blog, so be sure to keep this source http://9425473.blog.51cto.com/9415473/1670949

Overview of each node of the MongoDB replica set