The start-ts of a replication task corresponds to a Timestamp Oracle (TSO) in the upstream TiDB cluster. TiCDC requests data from this TSO in a replication task. Therefore, the start-ts of the replication task must meet the following requirements:
- The value of
start-tsis larger than thetikv_gc_safe_pointvalue of the current TiDB cluster. Otherwise, an error occurs when you create a task. - Before starting a task, ensure that the downstream has all data before
start-ts. For scenarios such as replicating data to message queues, if the data consistency between upstream and downstream is not required, you can relax this requirement according to your application need.
If you do not specify start-ts, or specify start-ts as 0, when a replication task is started, TiCDC gets a current TSO and starts the task from this TSO.