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Replication Reference

Replication Methods in the mongo Shell

Name Description
rs.add() Adds a member to a replica set.
rs.addArb() Adds an arbiter to a replica set.
rs.conf() Returns the replica set configuration document.
rs.freeze() Prevents the current member from seeking election as primary for a period of time. Returns basic help text for replica set functions.
rs.initiate() Initializes a new replica set.
rs.printReplicationInfo() Prints a formatted report of the replica set status from the perspective of the primary.
rs.printSecondaryReplicationInfo() Prints a formatted report of the replica set status from the perspective of the secondaries.
rs.printSlaveReplicationInfo() Deprecated since version 3.6.21: Use rs.printSecondaryReplicationInfo() instead.
rs.reconfig() Re-configures a replica set by applying a new replica set configuration object.
rs.remove() Remove a member from a replica set.
rs.secondaryOk() Allows read operations on secondary members for the MongoDB connection.
rs.status() Returns a document with information about the state of the replica set.
rs.stepDown() Causes the current primary to become a secondary which forces an election.
rs.syncFrom() Sets the member that this replica set member will sync from, overriding the default sync target selection logic.

Replication Database Commands

Name Description
applyOps Internal command that applies oplog entries to the current data set.
hello Displays information about this member’s role in the replica set, including whether it is the primary.
isMaster Deprecated. Use db.hello() instead.
replSetAbortPrimaryCatchUp Forces the elected primary to abort sync (catch up) then complete the transition to primary.
replSetFreeze Prevents the current member from seeking election as primary for a period of time.
replSetGetConfig Returns the replica set’s configuration object.
replSetGetStatus Returns a document that reports on the status of the replica set.
replSetInitiate Initializes a new replica set.
replSetMaintenance Enables or disables a maintenance mode, which puts a secondary node in a RECOVERING state.
replSetReconfig Applies a new configuration to an existing replica set.
replSetResizeOplog Dynamically resizes the oplog for a replica set member. Available for WiredTiger storage engine only.
replSetStepDown Forces the current primary to step down and become a secondary, forcing an election.
replSetSyncFrom Explicitly override the default logic for selecting a member to replicate from.
resync Forces a mongod to re-synchronize from the master. For master-slave replication only.

Replica Set Reference Documentation

Replica Set Configuration
Complete documentation of the replica set configuration object returned by rs.conf().
Replica Set Protocol Versions
Reference on the replica set protocol version.
Troubleshoot Replica Sets
Replica set trouble shooting guide.
The local Database
Complete documentation of the content of the local database that mongod instances use to support replication.
Replica Set Member States
Reference for the replica set member states.
Read Preference Reference
Complete documentation of the five read preference modes that the MongoDB drivers support.
Master Slave Replication
Reference on the deprecated master-slave replication.