MySQL 8.4 Release Notes
- 25.4.2.1 NDB 集群数据节点配置参数25.4.2.1 NDB Cluster Data Node Configuration Parameters
- 25.4.2.2 NDB 集群管理节点配置参数25.4.2.2 NDB Cluster Management Node Configuration Parameters
- 25.4.2.3 NDB 集群 SQL 节点和 API 节点配置参数25.4.2.3 NDB Cluster SQL Node and API Node Configuration Parameters
- 25.4.2.4 其他 NDB 集群配置参数25.4.2.4 Other NDB Cluster Configuration Parameters
- 25.4.2.5 NDB 集群 mysqld 选项和变量参考25.4.2.5 NDB Cluster mysqld Option and Variable Reference
接下来的几个部分提供了 NDB Cluster 节点配置参数的汇总表，这些参数用于 config.ini 文件中以管理节点行为的各个方面，以及 mysqld 从 my.cnf 文件或从命令行在作为 NDB Cluster 进程运行时读取的选项和变量。每个节点参数表列出了某一类型（ndbd、ndb_mgmd、mysqld、computer、tcp 或 shm）的参数。所有表格都包含该参数、选项或变量的数据类型，以及默认值、最小值和最大值（如适用）。The next several sections provide summary tables of NDB Cluster
node configuration parameters used in the
config.ini file to govern various aspects of
node behavior, as well as of options and variables read by
mysqld from a my.cnf file
or from the command line when run as an NDB Cluster process. Each
of the node parameter tables lists the parameters for a given type
(ndbd, ndb_mgmd,
mysqld, computer,
tcp, or shm). All tables
include the data type for the parameter, option, or variable, as
well as its default, minimum, and maximum values as applicable.
重启节点时的注意事项。 对于节点参数，这些表格还指出了需要哪种类型的重启（节点重启或系统重启）——以及是否必须使用 --initial 进行重启——以更改某个配置参数的值。在执行节点重启或初始节点重启时，必须依次重启集群的所有数据节点（也称为 滚动重启）。通过这种方式，可以在线更新标记为 node 的集群配置参数——即无需关闭集群。初始节点重启需要使用 --initial 选项重启每个 ndbd 进程。Considerations when restarting nodes.
For node parameters, these tables also indicate what type of
restart is required (node restart or system restart)—and
whether the restart must be done with
--initial—to change the value of a given
configuration parameter. When performing a node restart or an
initial node restart, all of the cluster's data nodes must
be restarted in turn (also referred to as a
rolling restart). It is
possible to update cluster configuration parameters marked as
node online—that is, without shutting
down the cluster—in this fashion. An initial node restart
requires restarting each ndbd process with
the --initial option.
系统重启需要对整个集群进行完全的关闭和重启。首次系统重启需要在关闭集群后备份集群、清除集群文件系统，然后在重启后从备份中恢复。A system restart requires a complete shutdown and restart of the entire cluster. An initial system restart requires taking a backup of the cluster, wiping the cluster file system after shutdown, and then restoring from the backup following the restart.
在任何集群重启中，必须重启集群的所有管理服务器，以使其读取更新后的配置参数值。In any cluster restart, all of the cluster's management servers must be restarted for them to read the updated configuration parameter values.
Important
数值型集群参数的值通常可以在没有问题的情况下增加，但建议逐步进行，以相对较小的增量进行调整。许多参数可以在在线状态下增加，使用滚动重启进行。Values for numeric cluster parameters can generally be increased without any problems, although it is advisable to do so progressively, making such adjustments in relatively small increments. Many of these can be increased online, using a rolling restart.
然而，降低这些参数的值——无论是通过节点重启、节点初始重启，还是集群的完整系统重启来完成——都不应轻率进行；建议只有在经过仔细规划和测试后才这样做。对于那些与内存使用和磁盘空间相关的参数尤其如此，例如 MaxNoOfTables、MaxNoOfOrderedIndexes 和 MaxNoOfUniqueHashIndexes。此外，一般情况下，与内存和磁盘使用相关的配置参数可以通过简单的节点重启来增加，但降低它们则需要进行初始节点重启。However, decreasing the values of such parameters—whether
this is done using a node restart, node initial restart, or even
a complete system restart of the cluster—is not to be
undertaken lightly; it is recommended that you do so only after
careful planning and testing. This is especially true with
regard to those parameters that relate to memory usage and disk
space, such as
MaxNoOfTables,
MaxNoOfOrderedIndexes,
and
MaxNoOfUniqueHashIndexes.
In addition, it is the generally the case that configuration
parameters relating to memory and disk usage can be raised using
a simple node restart, but they require an initial node restart
to be lowered.
由于这些参数中的一些可以用于配置多种类型的集群节点，因此它们可能出现在多个表中。Because some of these parameters can be used for configuring more than one type of cluster node, they may appear in more than one of the tables.
Note
4294967039 常常作为这些表中的最大值出现。该值在 NDBCLUSTER 源代码中定义为 MAX_INT_RNIL，等于 0xFFFFFEFF，或 232 −
28 − 1。4294967039 often appears as a maximum value
in these tables. This value is defined in the
NDBCLUSTER sources as
MAX_INT_RNIL and is equal to
0xFFFFFEFF, or
232 −
28 − 1.