update process [--remove-angel] --pid=os_pid process_id cluster_name
This command updates the status of the MySQL NDB Cluster process having
the process ID
process_id in the
cluster_name when the
status of the process is no longer reflected correctly in the
output of the
This typically happens in the following cases:
The process is a data node configured with
StopOnError=true, so that it would not be automatically restarted by mcmd after it has stopped. Instead of using the
start processcommand to restart the process, a user might have restarted the process manually, which would have restored the process but left mcmd without the knowledge of the restore. An
update processis then needed to restore the control of the process by mcmd.
The process is a node that has been stopped by mcmd but, for some reasons, its PID remains valid with the operating system. In some cases, the process might even be running again, without mcmd knowing or being able to control it.
mcmd cannot connect to a mysqld node due to various reasons (for example, there are already too many connections to the node); process status for the node becomes
failed, while the PID file continues to exist.
For release 8.0.30 and later only: When a
start processcommand for a mysqld node times out, mcmd looses control of the node. After fixing the issue on the mysqld node, run
update processto retore control of the node by mcmd.
The command works by importing the process into the control of
mcmd again. Checks performed on a process by
mcmd during a cluster import are performed
update process command.
Both the process's ID in the cluster
process_id) and its PID on the
operating system (specified with the
--pid option) are
required. Suppose that the process ID of a data node in the
3 and its PID on the operating system is
9846, the data node can be updated as shown
mcm> update process --pid=9846 3 mycluster; +------------------------------+ | Command result | +------------------------------+ | Process updated successfully | +------------------------------+ 1 row in set (33.07 sec)
For a data node or an SQL node, the command only works if there is at least 1 replica per nodegroup running.
update process supports a
option, which should be used when updating data nodes: it kills
any running angel
process for a data node and updates its PID file prior to
the actual update; those steps are necessary for the update