The Automatic Schema Synchronization mechanism, detailed in a two part series: part 1 and part 2, automatically detects and synchronizes mismatches in metadata between NDB Dictionary and MySQL Server’s Data Dictionary. Information about the mechanism is exposed through different MySQL Server status variables.…

In part 1, we took a brief, high-level look at the various protocols and mechanisms used to keep the Data Dictionary (DD) of MySQL servers connected to a MySQL Cluster in synchronization with each other and with the NDB Dictionary.…

Data nodes are the distributed, sharded storage core of MySQL NDB Cluster. Its data is usually accessed by MySQL Servers (also called SQL nodes in NDB parlance). The MySQL servers each have their own transactional Data Dictionary (DD) where all the metadata describing tables, databases, tablespaces, logfile groups, foreign keys, and other objects are stored for use by MySQL server.…