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MySQL 8.0 Reference Manual  /  ...  /  ndb_waiter — Wait for NDB Cluster to Reach a Given Status

23.5.30 ndb_waiter — Wait for NDB 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.

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.

Options that can be used with ndb_waiter are shown in the following table. Additional descriptions follow the table.

Table 23.50 Command-line options used with the program ndb_waiter

Format Description Added, Deprecated, or Removed

--character-sets-dir=path

Directory containing character sets

(Supported in all NDB releases based on MySQL 8.0)

--connect-retries=#

Number of times to retry connection before giving up

(Supported in all NDB releases based on MySQL 8.0)

--connect-retry-delay=#

Number of seconds to wait between attempts to contact management server

(Supported in all NDB releases based on MySQL 8.0)

--connect-string=connection-string,

-c

Same as --ndb-connectstring

(Supported in all NDB releases based on MySQL 8.0)

--core-file

Write core file on error; used in debugging

(Supported in all NDB releases based on MySQL 8.0)

--defaults-extra-file=path

Read given file after global files are read

(Supported in all NDB releases based on MySQL 8.0)

--defaults-file=path

Read default options from given file only

(Supported in all NDB releases based on MySQL 8.0)

--defaults-group-suffix=string

Also read groups with concat(group, suffix)

(Supported in all NDB releases based on MySQL 8.0)

--help,

-?

Display help text and exit

(Supported in all NDB releases based on MySQL 8.0)

--login-path=path

Read given path from login file

(Supported in all NDB releases based on MySQL 8.0)

--ndb-connectstring=connection-string,

-c

Set connect string for connecting to ndb_mgmd. Syntax: "[nodeid=id;][host=]hostname[:port]". Overrides entries in NDB_CONNECTSTRING and my.cnf

(Supported in all NDB releases based on MySQL 8.0)

--ndb-mgmd-host=connection-string,

-c

Same as --ndb-connectstring

(Supported in all NDB releases based on MySQL 8.0)

--ndb-nodeid=#

Set node ID for this node, overriding any ID set by --ndb-connectstring

(Supported in all NDB releases based on MySQL 8.0)

--ndb-optimized-node-selection

Enable optimizations for selection of nodes for transactions. Enabled by default; use --skip-ndb-optimized-node-selection to disable

(Supported in all NDB releases based on MySQL 8.0)

--no-contact,

-n

Wait for cluster to reach NO CONTACT state

(Supported in all NDB releases based on MySQL 8.0)

--no-defaults

Do not read default options from any option file other than login file

(Supported in all NDB releases based on MySQL 8.0)

--not-started

Wait for cluster to reach NOT STARTED state

(Supported in all NDB releases based on MySQL 8.0)

--nowait-nodes=list

List of nodes not to be waited for

(Supported in all NDB releases based on MySQL 8.0)

--print-defaults

Print program argument list and exit

(Supported in all NDB releases based on MySQL 8.0)

--single-user

Wait for cluster to enter single user mode

(Supported in all NDB releases based on MySQL 8.0)

--timeout=#,

-t

Wait this many seconds, then exit whether or not cluster has reached desired state

(Supported in all NDB releases based on MySQL 8.0)

--usage,

-?

Display help text and exit; same as --help

(Supported in all NDB releases based on MySQL 8.0)

--version,

-V

Display version information and exit

(Supported in all NDB releases based on MySQL 8.0)

--wait-nodes=list,

-w

List of nodes to be waited for

(Supported in all NDB releases based on MySQL 8.0)


Usage

ndb_waiter [-c connection_string]

Additional Options

  • --character-sets-dir

    Command-Line Format --character-sets-dir=path

    Directory containing character sets.

  • --connect-retries

    Command-Line Format --connect-retries=#
    Type Integer
    Default Value 12
    Minimum Value 0
    Maximum Value 12

    Number of times to retry connection before giving up.

  • --connect-retry-delay

    Command-Line Format --connect-retry-delay=#
    Type Integer
    Default Value 5
    Minimum Value 0
    Maximum Value 5

    Number of seconds to wait between attempts to contact management server.

  • --connect-string

    Command-Line Format --connect-string=connection-string
    Type String
    Default Value [none]

    Same as --ndb-connectstring.

  • --core-file

    Command-Line Format --core-file

    Write core file on error; used in debugging.

  • --defaults-extra-file

    Command-Line Format --defaults-extra-file=path
    Type String
    Default Value [none]

    Read given file after global files are read.

  • --defaults-file

    Command-Line Format --defaults-file=path
    Type String
    Default Value [none]

    Read default options from given file only.

  • --defaults-group-suffix

    Command-Line Format --defaults-group-suffix=string
    Type String
    Default Value [none]

    Also read groups with concat(group, suffix).

  • --login-path

    Command-Line Format --login-path=path
    Type String
    Default Value [none]

    Read given path from login file.

  • --help

    Command-Line Format --help

    Display help text and exit.

  • --ndb-connectstring

    Command-Line Format --ndb-connectstring=connection-string
    Type String
    Default Value [none]

    Set connect string for connecting to ndb_mgmd. Syntax: "[nodeid=id;][host=]hostname[:port]". Overrides entries in NDB_CONNECTSTRING and my.cnf.

  • --ndb-mgmd-host

    Command-Line Format --ndb-mgmd-host=connection-string
    Type String
    Default Value [none]

    Same as --ndb-connectstring.

  • --ndb-nodeid

    Command-Line Format --ndb-nodeid=#
    Type Integer
    Default Value [none]

    Set node ID for this node, overriding any ID set by --ndb-connectstring.

  • --ndb-optimized-node-selection

    Command-Line Format --ndb-optimized-node-selection

    Enable optimizations for selection of nodes for transactions. Enabled by default; use --skip-ndb-optimized-node-selection to disable.

  • --no-contact, -n

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

  • --no-defaults

    Command-Line Format --no-defaults

    Do not read default options from any option file other than login file.

  • --not-started

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

  • --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.

  • --print-defaults

    Command-Line Format --print-defaults

    Print program argument list and exit.

  • --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.

  • --usage

    Command-Line Format --usage

    Display help text and exit; same as --help.

  • --version

    Command-Line Format --version

    Display version information and exit.

  • --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.

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
Note

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

Prior to NDB 8.0.20, this program printed NDBT_ProgramExit - status upon completion of its run, due to an unnecessary dependency on the NDBT testing library. This dependency has been removed, eliminating the extraneous output.