MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0
Managing an NDB Cluster involves a number of tasks, the first of which is to configure and start NDB Cluster. This is covered in Section 23.3, “Configuration of NDB Cluster”, and Section 23.4, “NDB Cluster Programs”.
The next few sections cover the management of a running NDB Cluster.
For information about security issues relating to management and deployment of an NDB Cluster, see Section 23.5.17, “NDB Cluster Security Issues”.
There are essentially two methods of actively managing a running NDB
Cluster. The first of these is through the use of commands entered
into the management client whereby cluster status can be checked,
log levels changed, backups started and stopped, and nodes stopped
and started. The second method involves studying the contents of the
cluster log
ndb_
;
this is usually found in the management server's
node_id
_cluster.logDataDir
directory, but this
location can be overridden using the
LogDestination
option.
(Recall that node_id
represents the
unique identifier of the node whose activity is being logged.) The
cluster log contains event reports generated by
ndbd. It is also possible to send cluster log
entries to a Unix system log.
Some aspects of the cluster's operation can be also be
monitored from an SQL node using the
SHOW ENGINE NDB
STATUS
statement.
More detailed information about NDB Cluster operations is available
in real time through an SQL interface using the
ndbinfo
database. For more
information, see Section 23.5.14, “ndbinfo: The NDB Cluster Information Database”.
NDB statistics counters provide improved monitoring using the
mysql client. These counters, implemented in the
NDB kernel, relate to operations performed by or affecting
Ndb
objects, such as starting,
closing, and aborting transactions; primary key and unique key
operations; table, range, and pruned scans; blocked threads waiting
for various operations to complete; and data and events sent and
received by NDB Cluster. The counters are incremented by the NDB
kernel whenever NDB API calls are made or data is sent to or
received by the data nodes.
mysqld exposes the NDB API statistics counters as
system status variables, which can be identified from the prefix
common to all of their names (Ndb_api_
). The
values of these variables can be read in the
mysql client from the output of a
SHOW STATUS
statement, or by querying
either the Performance Schema
session_status
or
global_status
table. By comparing the
values of the status variables before and after the execution of an
SQL statement that acts on NDB
tables,
you can observe the actions taken on the NDB API level that
correspond to this statement, which can be beneficial for monitoring
and performance tuning of NDB Cluster.
MySQL Cluster Manager provides an advanced command-line interface that simplifies many otherwise complex NDB Cluster management tasks, such as starting, stopping, or restarting an NDB Cluster with a large number of nodes. The MySQL Cluster Manager client also supports commands for getting and setting the values of most node configuration parameters as well as mysqld server options and variables relating to NDB Cluster. MySQL Cluster Manager version 1.4.8 provides experimental support for NDB 8.0. See MySQL™ Cluster Manager 1.4.8 User Manual, for more information.