21.5.30 ndb_waiter — Wait for NDB Cluster to Reach a Given Status (original) (raw)

21.5.30 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 achieveSTARTED 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 aSTART orRESTART 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'sRESTART command.
• STARTING: The node'sndbd 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 21.46 Command-line options used with the program ndb_waiter

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:

$> 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:

$> 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.

$> ./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, thenndb_waiter tries to connect to a management on localhost, and reportsConnecting to mgmsrv at (null).

Prior to NDB 7.5.18 and 7.6.14, this program printedNDBT_ProgramExit -_`status`_ upon completion of its run, due to an unnecessary dependency on theNDBT testing library. This dependency is has now been removed, eliminating the extraneous output.