iredis/iredis/data/commands/sync.md

Initiates a replication stream from the master.

The SYNC command is called by Redis replicas for initiating a replication stream from the master. It has been replaced in newer versions of Redis by PSYNC.

For more information about replication in Redis please check the replication page.

@return

Non standard return value, a bulk transfer of the data followed by PING and write requests from the master.