This appendix contains terms and abbreviations that are found in
or useful to understanding the
NDB source code.
ACCess manager. Implemented as
DBACC kernel block,
which handles hash indexes of primary keys, providing fast
access to records.
NDB terms, this is any application that
accesses cluster data using the
including mysqld when functioning as an API
node. (MySQL servers acting in this capacity are also referred
to as “SQL nodes”.) Sometimes abbreviated
informally as “API”. See
NDB Cluster Nodes, Node Groups, Fragment Replicas, and Partitions.
BACKUP. In the NDB kernel, the block having this name performs online backups and checkpoints. For more information, see Section 4.1, “The BACKUP Block”.
Stands for Cluster
NDB kernel handling nonsignal requests to the
operating system, as well as configuration management,
interaction with the cluster management server, and interaction
between various kernel blocks and the
virtual machine. See
Section 4.2, “The CMVMI Block”, for more
CNTR. Stands for restart CoordiNaToR. See Section 4.14, “The NDBCNTR Block”, for more information.
Information block provides
support for the
information database used to obtain information about data node
Section 4.6, “The DBINFO Block”.
DBTC. The transaction coordinator (also sometimes written simply as TC). See Section 4.9, “The DBTC Block”, for more information.
DICTionary kernel block. Also
Section 4.4, “The DBDICT Block”.
NDB kernel block. See
Section 4.5, “The DBDIH Block”.
Manager. This set of NDB kernel
blocks executes the code that manages the data handled on a
given data node. It includes the
Each such set of modules is referred to as an LDM instance, and is responsible for tuple storage, hash and T-tree indexes, page buffer and tablespace management, writing and restoring local checkpoints, and Disk Data log management. A data node can have multiple LDM instances, each of which can be distributed among a set of threads. Each LDM instance works with its own partition of the data.
kernel block, used for NDB Cluster Disk Data tables. See
Section 4.13, “The LGMAN Block”.
kernel block, discussed in
Section 4.7, “The DBLQH Block”.
MGM. ManaGeMent node (or management server). Implemented as the ndb_mgmd server daemon. Responsible for passing cluster configuration information to data nodes and performing functions such as starting and stopping nodes. Accessed by the user by means of the cluster management client (ndb_mgm). A discussion of management nodes can be found in ndb_mgmd — The NDB Cluster Management Server Daemon.
The cluster management block in the
kernel. It responsibilities include monitoring heartbeats from
data and API nodes. See
Section 4.17, “The QMGR Block”, for more
RBR. Row-Based Replication. NDB Cluster Replication is row-based replication. See NDB Cluster Replication.
STTOR. STarT Or Restart
SUMA. The cluster SUbscription MAnager. See Section 4.19, “The SUMA Block”.
TC. Transaction Coordinator. See Section 4.9, “The DBTC Block”.
Stands for TRansactions and
which are managed by the
NDB kernel block
having this name. See
Section 4.23, “The TRIX Block”.
TSMAN. Table space manager. Handles tablespaces for NDB Cluster Disk Data. See Section 4.22, “The TSMAN Block”, for more information.
TUPle. Unit of data storage.
Also used (along with DBTUP) to
refer to the
NDB kernel's tuple management
block, which is discussed in
Section 4.10, “The DBTUP Block”.