Spec-Zone .ru
спецификации, руководства, описания, API
|
ndbinfo
MySQL Cluster Information DatabaseManaging a MySQL Cluster involves a number of tasks, the first of which is to configure and start MySQL Cluster. This is covered in Section 17.3, "Configuration of MySQL Cluster NDB 7.3", and Section 17.4, "MySQL Cluster Programs".
The next few sections cover the management of a running MySQL Cluster.
For information about security issues relating to management and deployment of a MySQL Cluster, see Section 17.5.11, "MySQL Cluster Security Issues".
There are essentially two methods of actively managing a running MySQL 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 MySQL Cluster operations is available in real time through an SQL interface
using the ndbinfo
database. For more information, see Section
17.5.10, "The ndbinfo
MySQL 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
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 SESSION_STATUS
table or the GLOBAL_STATUS
table (in the INFORMATION_SCHEMA
database). 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 MySQL Cluster.
MySQL Enterprise Monitor can also be used to monitor MySQL Servers that are part of a MySQL Cluster deployment.
MySQL Enterprise Monitor 2.3, added a MySQL Cluster advisor, including a set of graphs providing information on
MySQL Cluster resources, and defining rules for alerts on key information from data nodes such as DataMemory
usage. This information is made available to MySQL Enterprise Monitor 2.3 or later by any MySQL Server which is
connected to the MySQL Cluster, using ndbinfo
. The advisor could be run against a single MySQL Server in the
Cluster, or against a pair in order to provide a higher level of availability for the monitoring service. For
more information, see the
MySQL Cluster Manager provides an advanced command-line interface that simplifies many otherwise complex MySQL
Cluster management tasks, such as starting, stopping, or restarting a MySQL 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 MySQL Cluster. MySQL Cluster Manager 1.1 provides support for adding
data nodes online. See the