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- Replication Concepts
Replication Concepts¶
These documents describe and provide examples of replica set operation, configuration, and behavior. For an overview of replication, see Replication Introduction. For documentation of the administration of replica sets, see Replica Set Tutorials. The Replication Reference documents commands and operations specific to replica sets.
- Replica Set Members
Introduces the components of replica sets.
- Replica Set Primary
- The primary is the only member of a replica set that accepts write operations.
- Replica Set Secondary Members
- Secondary members replicate the primary’s data set and accept read operations. If the set has no primary, a secondary can become primary.
- Priority 0 Replica Set Members
- Priority 0 members are secondaries that cannot become the primary.
- Hidden Replica Set Members
- Hidden members are secondaries that are invisible to applications. These members support dedicated workloads, such as reporting or backup.
- Replica Set Arbiter
- An arbiter does not maintain a copy of the data set but participate in elections.
- Replica Set Deployment Architectures
Introduces architectural considerations related to replica sets deployment planning.
- Three Member Replica Sets
- Three-member replica sets provide the minimum recommended architecture for a replica set.
- Replica Set High Availability
Presents the details of the automatic failover and recovery process with replica sets.
- Replica Set Elections
- Elections occur when the primary becomes unavailable and the replica set members autonomously select a new primary.
- Read Preference
- Applications specify read preference to control how drivers direct read operations to members of the replica set.
- Replication Processes
- Mechanics of the replication process and related topics.
- Master Slave Replication
- Master-slave replication provided redundancy in early versions of MongoDB. Replica sets replace master-slave for most use cases.