rs.syncFrom()
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Definition
rs.syncFrom()Temporarily overrides the default sync target for the current member.
Important
mongosh Method
This page documents a
mongoshmethod. This is not the documentation for database commands or language-specific drivers, such as Node.js.For the database command, see the
replSetFreezecommand.For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.
Specify the name of the member you want to replicate from in the form of
[hostname]:[port].
Compatibility
This method is available in deployments hosted in the following environments:
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
Behavior
Sync Logic
If an initial sync operation is in progress when you run
replSetSyncFrom, replSetSyncFrom stops the in-progress initial sync and
restarts the sync process with the new target.
Only modify the default sync logic as needed, and always exercise caution.
Target
The member to sync from must be a valid source for data in the set. To sync from a member, the member must:
Have data. It cannot be an arbiter, in startup or recovering mode, and must be able to answer data queries.
Be accessible.
Be a member of the same set in the replica set configuration.
Build indexes with the
members[n].buildIndexessetting.A different member of the set, to prevent syncing from itself.
If you attempt to replicate from a member that is more than 10 seconds
behind the current member, mongod will log a warning but will
still replicate from the lagging member. See also
Replication Lag and Flow Control.
Persistence
replSetSyncFrom provide a temporary override of default behavior.
mongod will revert to the default sync behavior in the
following situations:
Example
To use the rs.syncFrom() helper in mongosh:
rs.syncFrom("myHost:27017");