NDB Cluster Internals  /  NDB Kernel Blocks

Chapter 4 NDB Kernel Blocks

This chapter provides information about the major software modules making up the NDB kernel. The files containing the implementations of these blocks can be found in several directories under storage/ndb/src/kernel/blocks/ in the NDB Cluster source tree.

As described elsewhere, the NDB kernel makes use of a number of different threads to perform various tasks. Kernel blocks are associated with these threads as shown in the following table:

Table 4.1 NDB kernel blocks and NDB kernel threads

Thread (ThreadConfig Name) Kernel Blocks
Main (main) CMVMI (primary), DBINFO, DBDICT, DBDIH, NDBCNTR, QMGR, DBUTIL
LDM (ldm) DBTUP, DBACC, DBLQH (primary), DBTUX, BACKUP, TSMAN, LGMAN, PGMAN, RESTORE
TC (tc) DBTC (primary), TRIX
Replication (rep) SUMA (primary), DBSPJ
Receiver (recv) CMVMI
Sender (send) CMVMI
I/O (io) NDBFS

You can obtain more information about these threads from the documentation for the ThreadConfig data node configuration parameter.