• MySQL 5.1 Reference Manual :: 17 MySQL Cluster NDB 6.X/7.X :: 17.4 MySQL Cluster Programs :: 17.4.22 ndb_waiter — Wait for MySQL Cluster to Reach a Given Status
  • 17.4.22. ndb_waiter — Wait for MySQL Cluster to Reach a Given Status

    ndb_waiter repeatedly (each 100 milliseconds) prints out the status of all cluster data nodes until either the cluster reaches a given status or the --timeout limit is exceeded, then exits. By default, it waits for the cluster to achieve STARTED status, in which all nodes have started and connected to the cluster. This can be overridden using the --no-contact and --not-started options (see Additional Options).

    The node states reported by this utility are as follows:

    • NO_CONTACT: The node cannot be contacted.

    • UNKNOWN: The node can be contacted, but its status is not yet known. Usually, this means that the node has received a START or RESTART command from the management server, but has not yet acted on it.

    • NOT_STARTED: The node has stopped, but remains in contact with the cluster. This is seen when restarting the node using the management client's RESTART command.

    • STARTING: The node's ndbd process has started, but the node has not yet joined the cluster.

    • STARTED: The node is operational, and has joined the cluster.

    • SHUTTING_DOWN: The node is shutting down.

    • SINGLE USER MODE: This is shown for all cluster data nodes when the cluster is in single user mode.

    Usage:

    ndb_waiter [-c connect_string]
    

    Additional Options:

    • --no-contact, -n

      Instead of waiting for the STARTED state, ndb_waiter continues running until the cluster reaches NO_CONTACT status before exiting.

    • --not-started

      Instead of waiting for the STARTED state, ndb_waiter continues running until the cluster reaches NOT_STARTED status before exiting.

    • --timeout=seconds, -t seconds

      Time to wait. The program exits if the desired state is not achieved within this number of seconds. The default is 120 seconds (1200 reporting cycles).

    • --single-user

      The program waits for the cluster to enter single user mode.

    • --nowait-nodes=list

      When this option is used, ndb_waiter does not wait for the nodes whose IDs are listed. The list is comma-delimited; ranges can be indicated by dashes, as shown here:

      shell> ndb_waiter --nowait-nodes=1,3,7-9
      

      Important

      Do not use this option together with the --wait-nodes option.

      This option was added in MySQL Cluster NDB 6.2.1.

    • --wait-nodes=list, -w list

      When this option is used, ndb_waiter waits only for the nodes whose IDs are listed. The list is comma-delimited; ranges can be indicated by dashes, as shown here:

      shell> ndb_waiter --wait-nodes=2,4-6,10
      

      Important

      Do not use this option together with the --nowait-nodes option.

      This option was added in MySQL Cluster NDB 6.3.34, 7.0.15, and 7.1.4.

    Sample Output.  Shown here is the output from ndb_waiter when run against a 4-node cluster in which two nodes have been shut down and then started again manually. Duplicate reports (indicated by “...”) are omitted.

    shell> ./ndb_waiter -c localhost
    
    Connecting to mgmsrv at (localhost)
    State node 1 STARTED
    State node 2 NO_CONTACT
    State node 3 STARTED
    State node 4 NO_CONTACT
    Waiting for cluster enter state STARTED
    
    ...
    
    State node 1 STARTED
    State node 2 UNKNOWN
    State node 3 STARTED
    State node 4 NO_CONTACT
    Waiting for cluster enter state STARTED
    
    ...
    
    State node 1 STARTED
    State node 2 STARTING
    State node 3 STARTED
    State node 4 NO_CONTACT
    Waiting for cluster enter state STARTED
    
    ...
    
    State node 1 STARTED
    State node 2 STARTING
    State node 3 STARTED
    State node 4 UNKNOWN
    Waiting for cluster enter state STARTED
    
    ...
    
    State node 1 STARTED
    State node 2 STARTING
    State node 3 STARTED
    State node 4 STARTING
    Waiting for cluster enter state STARTED
    
    ...
    
    State node 1 STARTED
    State node 2 STARTED
    State node 3 STARTED
    State node 4 STARTING
    Waiting for cluster enter state STARTED
    
    ...
    
    State node 1 STARTED
    State node 2 STARTED
    State node 3 STARTED
    State node 4 STARTED
    Waiting for cluster enter state STARTED
    
    NDBT_ProgramExit: 0 - OK
    

    Note

    If no connectstring is specified, then ndb_waiter tries to connect to a management on localhost, and reports Connecting to mgmsrv at (null).