The limitations described in this section relate to functionality in the MySQL Server that is unsupported or reduced, or otherwise differs when using it with MySQL Cluster Manager.
Replication. Replication is currently not directly supported by MySQL Cluster Manager. See Section 6.3, “MySQL Cluster Manager Limitations Relating to MySQL NDB Cluster”, for more information.
Limited mysqld option modifier support.
MySQL Cluster Manager does not recognize the
--disable prefixes for
mysqld options used as MySQL Cluster Manager configuration
attributes (for a description of these modifiers, see
Program Option Modifiers). For example, the command
loose-skip-innodb:mysqld=true mycluster; fails with
the error No such config variable loose-skip-innodb
for process mysqld.
--skip option modifier is supported in some
but not all cases, so that commands such as
skip-grant-tables:mysqld=true mycluster; can be used
with MySQL Cluster Manager, while
mycluster; cannot. (Bug #48559, Bug #47779)
Dashes and underscores in MySQL option and variable names.
When using the mysql client or other MySQL
client applications, many MySQL system options and variables can
be named using either dashes or underscores in their names. For
example, you can use either
ndb-batch-size with the MySQL Server, and the
variable is set correctly. This is not the case in MySQL Cluster Manager, where
only the forms using underscores are accepted as attribute
names. For example, assuming that
is a viable cluster, the command
ndb_batch_size:mysqld=65536 mycluster; works to set
the size of ndb_batch_size on all mysqld
processes in the cluster, but
ndb-batch-size:mysqld=65536 mycluster; fails.
Dependencies between MySQL Cluster Manager mysqld attributes and MySQL server variables. MySQL Cluster Manager does not track dependencies between mysqld attributes (MySQL server options and system variables). That means MySQL Cluster Manager might have mysqld started successfully and report so, even though the server has ended up in a non-functional state because dependent attributes were set inconsistently. It is therefore a good idea for users to check the mysqld attributes before starting the node and the mysql log for status of the node after it has been started.
MySQL Cluster Manager mysqld attributes and MySQL user variables. MySQL user variables are not accessible as MySQL Cluster Manager configuration attributes.
Unsupported MySQL 8.0 Features. These MySQL 8.0 features are not supported by MySQL Cluster Manager 8.0:
--upgradeoption for mysqld.
SET PERSISTstatement for persisting system variables.