1. 1.28 canalhistorical

    1. What Is canal - A component that parses MySQL bin-log 2. Why canal Is Needed - Obtain incremental changes to MySQL data and synchronize them to components such as Elasticsearch and Redis 3. canal Principle - Essentially simulates a replica in primary-replica replication, so it is the same as MySQL Primary-Replica Replication.md 4. How to Use canal