MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

22.4.30 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:

The following table includes options that are specific to the NDB Cluster native backup restoration program ndb_waiter. Additional descriptions follow the table. For options common to most NDB Cluster programs (including ndb_waiter), see Section 22.4.31, “Options Common to NDB Cluster Programs — Options Common to NDB Cluster Programs”.

Table 22.350 Command-line options for the ndb_waiter program

Format Description Added, Deprecated, or Removed

--no-contact,

-n

Wait for cluster to reach NO CONTACT state

All NDB 8.0 releases

--not-started

Wait for cluster to reach NOT STARTED state

All NDB 8.0 releases

--single-user

Wait for cluster to enter single user mode

All NDB 8.0 releases

--timeout=#,

-t

Wait this many seconds, then exit whether or not cluster has reached desired state; default is 2 minutes (120 seconds)

All NDB 8.0 releases

--nowait-nodes=list

List of nodes not to be waited for.

All NDB 8.0 releases

--wait-nodes=list,

-w

List of nodes to be waited for.

All NDB 8.0 releases


Usage

ndb_waiter [-c connection_string]

Additional Options

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 connection string is specified, then ndb_waiter tries to connect to a management on localhost, and reports Connecting to mgmsrv at (null).