> [!ReplicationSlotsyncMain] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_activity_replicationslotsyncmain.png"></td><td><b>Wait Category</b></td><td>Activity</td></tr><tr><td><b>Mechanism</b></td><td><code>ReplSlotSyncMain</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Distributed/Redistribute">Redistribute</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/Network">Network</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3"><b>Replication Slot Sync</b> process is idling between its scheduled synchronization cycles. Introduced to improve the reliability of failovers, this process ensures that logical replication slots—which track how much data a subscriber has consumed—are mirrored from the primary to the standby.</td></tr></table>