The limitations discussed in this section occur by intention or design in MySQL Cluster Manager 1.4.7. 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 multithreaded
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
multithreaded data nodes are not supported in MySQL NDB Cluster 6.3 and
command is useful only with clusters running MySQL NDB Cluster 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 NDB Cluster host
under MySQL Cluster Manager, you must reference it using its IPv4 address.
Otherwise, mcm will be unable to connect to
the agent process on that host.
Use of antivirus software on Windows platforms. On-access scanning by antivirus software on Windows platforms might cause access to the cluster configuration file being denied for the mcmd agent, causing updates for the cluster configuration to fail sometimes.