4.4.6 The show status Command

show status --cluster|-c cluster_name
show status --operation|-o cluster_name
show status --backup|-b cluster_name
show status --process|-r cluster_name

This command is used to check the status of clusters, cluster processes, backups, and commands issued in the MySQL Cluster Manager client. The type of status returned depends on which of the four options of --cluster (short form: -c), --operation (short form: -o), --backup (short form: -b), or --process (short form -r) is used with the command. (If none of these is used, --cluster is assumed.) These options are described in more detail in the next few paragraphs.

--cluster

When this option is used, show status reports on the status of the cluster named cluster_name, as shown in this example:

mcm> show status --cluster mycluster;
+-----------+-------------------+---------+
| Cluster   | Status            | Comment |
+-----------+-------------------+---------+
| mycluster | fully operational |         |
+-----------+-------------------+---------+
1 row in set (0.01 sec)

When used with the --cluster option (short form: -c), the output of this command consist of two columns. The Cluster column contains the name of the cluster. The Status column contains a description of the cluster's status; possible values and their meanings are shown in the following table:

Table 4.1 Status values shown by show status --cluster

Status Value	Meaning
fully operational	All cluster processes are running.
operational	All node groups are up and running, but at least one data node process (ndbd or ndbmtd) is not running. The cluster is online, but you should determine why any “missing” data nodes are not running and correct the problem as soon as possible.
non-operational	The cluster is not operational, because at least one node group is offline. You must investigate and fix the problem or problems, then restart the cluster, before the cluster can be used for data storage and retrieval operations.
stopped	The cluster is not running, because it has been stopped by the user. This normally does not indicate any problem as such, but you must restart the cluster before it can be used by any applications.
created	The cluster has been created successfully using the create cluster command, but has never been started. You must start the cluster using the start cluster command before you can make use of it.
unknown	The MySQL Cluster Manager was unable to determine the cluster's status. This may or may not indicate a problem with the cluster; it is possible that the problem lies with one or more MySQL Cluster Manager agents or the MySQL Cluster Manager client. You should attempt to determine the status of the cluster by other means, such as using show status --process in the MySQL Cluster Manager client (described later in this section), or employing one of the commands available in the ndb_mgm client (see ndb_mgm — The NDB Cluster Management Client) such as SHOW or ALL STATUS.

--operation option

When the --operation option (short form: -o) is used, it causes SHOW STATUS to display the status of the latest command to be executed. This includes commands that were issued using the --background option (short form -bg). An example of this command is shown here:

mcm> show status --operation mycluster;
+-----------------+-----------+--------------+
| Command         | Status    | Description  |
+-----------------+-----------+--------------+
| restart cluster | executing | <no message> |
+-----------------+-----------+--------------+
1 row in set (1.60 sec)

The output contains 3 columns, described in the following list:

• Command.  The text of the command last issued (previous to the show status --operation command), less any options or arguments.

• Status.  The current state of the command. Possible values and their meanings are listed later in this section.

• Description.  In some cases, depending on the command and its status, this column may contain additional information. Otherwise, <no message> is displayed here.

Possible values for the Status column, together with descriptions of these values, are shown in the following table:

Table 4.2 Status values shown by show status --operation

Status Value	Description
executing	MySQL Cluster Manager is executing the command, but has not yet completed doing so.
finished	The command has executed (and completed) successfully.
failed	The command failed to execute. The Description column may contain information about the reason for the failure.
unknown	MySQL Cluster Manager was unable to determine the status of this command.

--backup option

When this option is used, show status reports on the status of the backup process for the cluster named cluster_name, as shown in the following examples:

mcm> show status --backup mycluster;
+-----------------------------------------+
| Command result                          |
+-----------------------------------------+
| No backup currently active in mycluster |
+-----------------------------------------+
1 row in set (0.05 sec)

mcm> show status --backup mycluster;
+-----------------------------------------+
| Command result                          |
+-----------------------------------------+
| BackupId 5 currently active in mycluster|
+-----------------------------------------+
1 row in set (0.09 sec)

--process option

When run with this option, show status returns information about each process in the cluster named cluster_name, as shown in this example:

mcm> show status --process mycluster;
+------+----------+----------+---------+-----------+
| Id   | Process  | Host     | Status  | Nodegroup |
+------+----------+----------+---------+-----------+
| 1    | ndb_mgmd | tonfisk  | running |           |
| 2    | ndbd     | flundra  | running | 0         |
| 3    | ndbd     | grindval | running | 0         |
| 4    | mysqld   | lax      | running |           |
+------+----------+----------+---------+-----------+
4 rows in set (1.67 sec)

When the --process option (short form: -r) is used with show status, the output contains 5 columns, described in the following list:

• Id.  This is the node ID of the process as a node in cluster cluster_name.

• Process.  The type of process, that is, the name of the corresponding MySQL Cluster executable. Allowed values are ndb_mgmd, ndbd, ndbmtd, and mysqld.

• Host.  The hostname or IP address of the computer where the process is running.

• Status.  The state or condition of this process. Possible values for this column are given later in this section.

• Nodegroup.  If the Process is ndbd or ndbmtd—that is, if the process is a data node process—then this column shows the ID of the node group to which the process belongs. For any other value of Process, this column is empty.

Possible values for the Status column are shown in the following table, together with a description of what this value represents:

Table 4.3 Status values shown by show status --process

Status Value	Meaning
running	The process is running normally.
stopped	The process has been stopped by the user.
added	The process has been added to the cluster, but not yet started.
starting	The process has been started, but is not yet fully running. (For data nodes, you can determine which start phase the node is currently in by using the status command in the ndb_mgm client.)
stopping	The process has received a command to stop, and is now shutting down.
failed	The process has shut down unexpectedly (likely to have crashed). You should determine the cause for this unplanned shutdown, fix the problem, and restart the process as soon as possible.
import	The process is part of a cluster that was created for import, but the actual migration of processes and data from the original cluster has not yet taken place. start process and stop process commands fail for this process until this migration has occurred.
unknown	MySQL Cluster Manager is unable to establish the current status of this process. You should try to determine its status using other means.

You must supply the name of an existing cluster with this command, or else show status fails with an error, as shown here:

mcm> show status;
ERROR 6 (00MGR): Illegal number of operands

mcm> show status -c nosuchcluster;
ERROR 5001 (00MGR): Cluster nosuchcluster not defined

Important

Do not confuse this command with the MySQL SHOW STATUS statement, which has a different syntax, and which can be used only in the standard mysql client. The MySQL Cluster Manager client command accepts only those options shown at the beginning of this section, and does not accept a LIKE or WHERE clause.