TiCDC is a tool for replicating the incremental data of TiDB. This tool is implemented by pulling TiKV change logs. It can restore data to a consistent state with any upstream TSO, and provides TiCDC Open Protocol to support other systems to subscribe to data changes.
When TiCDC is running, it is a stateless node that achieves high availability through etcd in PD. The TiCDC cluster supports creating multiple replication tasks to replicate data to multiple different downstream platforms.
The architecture of TiCDC is shown in the following figure:
TiKV CDC component: Only outputs key-value (KV) change logs.
capture: The operating process of TiCDC. Multiple
captures form a TiCDC cluster that replicates KV change logs.
capturepulls a part of KV change logs.
This section introduces the replication features of TiCDC.
Currently, the TiCDC sink component supports replicating data to the following downstream platforms:
You can write blacklist and whitelist filtering rules to filter or only replicate all changed data in certain databases or tables. The filtering rules are similar to those of MySQL such as
To replicate data to TiDB or MySQL, you must ensure that the following requirements are satisfied to guarantee data correctness: