This block provides data distribution (partitioning) management
services. It is responsible for maintaining data fragments and
replicas, handling of local and global checkpoints; it also
manages node and system restarts. It contains the following
files, all found in the directory
Dbdih.hpp: This file contains the
definition of the
Dbdih class, as well as
FileRecordPtr type, which is used to
keep storage information about a fragment and its replicas.
If a fragment has more than one backup replica, then a list
of the additional ones is attached to this record. This
record also stores the status of the fragment, and is
DbdihMain.cpp: Contains definitions of
Dbdih class methods.
version of the
printSysfile.cpp in the
Dbdih data and records; also contains the
LCP.txt: Contains developer notes about
the exchange of messages between
LQH that takes place during a local
printSysfile.cpp: This file contains
the source code for ndb_print_sys_file.
For information about using this utility, see
ndb_print_sys_file — Print NDB System File Contents.
Sysfile.hpp: Contains the definition of
Sysfile structure; in other words,
the format of an
NDB system file. See
Section 8.1, “MySQL Cluster File Systems”, for more
NDB system files.
This block often makes use of
on the data nodes to accomplish distributed tasks, such as
global checkpoints and system restarts.
This block is implemented as the
whose definition may be found in the file