The limitations discussed in this section occur by intention or design in MySQL Cluster Manager 1.2.3. Some of these items may become obsolete in future versions; we will update this section accordingly if and as those changes come about.
change process command.
command can be used only to exchange an ndbd
process for an ndbmtd process, or the
reverse. That is, in effect, it can be used only to switch a
data node between a single-threaded process and a multi-threaded
process. It cannot be used for changing a cluster node's
type (for example, you cannot change a data node to an SQL node,
management node, or NDB API application node).
Because of this restriction, and due to the fact that
multi-threaded data nodes are not supported in MySQL Cluster NDB
6.3 and earlier, the
process command is useful only with clusters running
MySQL Cluster NDB 7.0 or newer.
Concurrent client sessions unsupported.
Currently there is no negotation or arbitration between multiple
mcm clients. While it is possible to use the
client from multiple locations, we do not support
concurrent client sessions. You should be
careful always to allow a command issued in one
mcm client session to finish executing before
issuing a new command in a different client session. This is
true especially when using the
--background option with mcm
client commands; see Backgrounded commands and error handling.
IPv6 and host names (Windows).
When IPv6 support is enabled on Windows systems, host names
localhost are resolved using IPv6.
When an IPv6-enabled Windows system is used as a MySQL Cluster
host under MySQL Cluster Manager, you must reference it using its IPv4 address,
localhost, if this is applicable.
Otherwise, mcm will be unable to connect to
the agent process on that host.
No removal of hosts, processes.
Once a host is added to a management site using the
add hosts command, it cannot be
removed with MySQL Cluster Manager.
Once a process has been added to a cluster using the
add process command, it cannot be
removed from the cluster using MySQL Cluster Manager.