NDB Cluster Internals  /  NDB Kernel Blocks  /  The NDBCNTR Block

4.14 The NDBCNTR Block

This is a cluster management block that handles block initialisation and configuration. During the data node startup process, it takes over from the QMGR block and continues the process. It also assists with graceful (planned) shutdowns of data nodes. This block is implemented in storage/ndb/src/kernel/blocks/ndbcntr, which contains these files:

  • Ndbcntr.hpp: Defines the Ndbcntr class used to implement cluster management functions.

  • NdbcntrInit.cpp: Initializers for Ndbcntr data and records.

  • NdbcntrMain.cpp: Implements methods used for starts, restarts, and reading of configuration data.

  • NdbcntrSysTable.cpp: NDBCNTR creates and initializes system tables on initial system start. The tables are defined in static structs in this file.