17.4.1. ndbd — The MySQL Cluster Data Node Daemon

--bind-address

Causes ndbd to bind to a specific network interface (host name or IP address). This option has no default value.

--daemon, -d

Instructs ndbd or ndbmtd to execute as a daemon process. This is the default behavior. --nodaemon can be used to prevent the process from running as a daemon.

This option has no effect when running ndbd or ndbmtd on Windows platforms.

--nodaemon

Prevents ndbd or ndbmtd from executing as a daemon process. This option overrides the --daemon option. This is useful for redirecting output to the screen when debugging the binary.

The default behavior for ndbd and ndbmtd on Windows is to run in the foreground, making this option unnecessary on Windows platforms, where it has no effect.

--foreground

Causes ndbd or ndbmtd to execute as a foreground process, primarily for debugging purposes. This option implies the --nodaemon option.

This option has no effect when running ndbd or ndbmtd on Windows platforms.

--initial

Instructs ndbd to perform an initial start. An initial start erases any files created for recovery purposes by earlier instances of ndbd. It also re-creates recovery log files. Note that on some operating systems this process can take a substantial amount of time.

An --initial start is to be used only when starting the ndbd process under very special circumstances; this is because this option causes all files to be removed from the MySQL Cluster file system and all redo log files to be re-created. These circumstances are listed here:

Use of this option prevents the StartPartialTimeout and StartPartitionedTimeout configuration parameters from having any effect.

It is permissible to use this option when starting the cluster for the very first time (that is, before any data node files have been created); however, it is not necessary to do so.

--initial-start

This option is used when performing a partial initial start of the cluster. Each node should be started with this option, as well as --nowait-nodes.

Suppose that you have a 4-node cluster whose data nodes have the IDs 2, 3, 4, and 5, and you wish to perform a partial initial start using only nodes 2, 4, and 5—that is, omitting node 3:

shell> ndbd --ndb-nodeid=2
                    --nowait-nodes=3 --initial-startshell> ndbd
                    --ndb-nodeid=4 --nowait-nodes=3 --initial-startshell> ndbd --ndb-nodeid=5 --nowait-nodes=3
                    --initial-start

When using this option, you must also specify the node ID for the data node being started with the --ndb-nodeid option.

--nowait-nodes=node_id_1[, node_id_2[, ...]]

This option takes a list of data nodes which for which the cluster will not wait for before starting.

This can be used to start the cluster in a partitioned state. For example, to start the cluster with only half of the data nodes (nodes 2, 3, 4, and 5) running in a 4-node cluster, you can start each ndbd process with --nowait-nodes=3,5. In this case, the cluster starts as soon as nodes 2 and 4 connect, and does not wait StartPartitionedTimeout milliseconds for nodes 3 and 5 to connect as it would otherwise.

If you wanted to start up the same cluster as in the previous example without one ndbd (say, for example, that the host machine for node 3 has suffered a hardware failure) then start nodes 2, 4, and 5 with --nowait-nodes=3. Then the cluster will start as soon as nodes 2, 4, and 5 connect and will not wait for node 3 to start.

--nostart, -n

Instructs ndbd not to start automatically. When this option is used, ndbd connects to the management server, obtains configuration data from it, and initializes communication objects. However, it does not actually start the execution engine until specifically requested to do so by the management server. This can be accomplished by issuing the proper START command in the management client (see Section 17.5.2, "Commands in the MySQL Cluster Management Client").

--install[=name]

Causes ndbd to be installed as a Windows service. Optionally, you can specify a name for the service; if not set, the service name defaults to ndbd. Although it is preferable to specify other ndbd program options in a my.ini or my.cnf configuration file, it is possible to use together with --install. However, in such cases, the --install option must be specified first, before any other options are given, for the Windows service installation to succeed.

It is generally not advisable to use this option together with the --initial option, since this causes the data node file system to be wiped and rebuilt every time the service is stopped and started. Extreme care should also be taken if you intend to use any of the other ndbd options that affect the starting of data nodes—including --initial-start, --nostart, and --nowait-nodes—together with --install, and you should make absolutely certain you fully understand and allow for any possible consequences of doing so.

The --install option has no effect on non-Windows platforms.

--remove[=name]

Causes an ndbd process that was previously installed as a Windows service to be removed. Optionally, you can specify a name for the service to be uninstalled; if not set, the service name defaults to ndbd.

The --remove option has no effect on non-Windows platforms.

--connect-retries=#

Determines the number of times that the data node attempts to contact a management server when starting. Setting this option to -1 causes the data node to keep trying to make contact indefinitely. The default is 12 attempts. The time to wait between attempts is controlled by the --connect-delay option.

--connect-delay=#

Determines the time to wait between attempts to contact a management server when starting (the time between attempts is controlled by the --connect-retries option). The default is 5 attempts.

This option was added in MySQL Cluster NDB 7.2.9.

ndb_node_id_error.log is a file containing records of all crashes which the referenced ndbd process has encountered. Each record in this file contains a brief error string and a reference to a trace file for this crash. A typical entry in this file might appear as shown here:

Date/Time: Saturday 30 July 2004 - 00:20:01Type of error: errorMessage: Internal program error (failed ndbrequire)Fault ID: 2341Problem data: DbtupFixAlloc.cppObject of reference: DBTUP (Line: 173)ProgramName: NDB KernelProcessID: 14909TraceFile: ndb_2_trace.log.2***EOM***

Listings of possible ndbd exit codes and messages generated when a data node process shuts down prematurely can be found in ndbd Error Messages.

ndb_node_id_trace.log.trace_id is a trace file describing exactly what happened just before the error occurred. This information is useful for analysis by the MySQL Cluster development team.

It is possible to configure the number of these trace files that will be created before old files are overwritten. trace_id is a number which is incremented for each successive trace file.

ndb_node_id_trace.log.next is the file that keeps track of the next trace file number to be assigned.

ndb_node_id_out.log is a file containing any data output by the ndbd process. This file is created only if ndbd is started as a daemon, which is the default behavior.

ndb_node_id.pid is a file containing the process ID of the ndbd process when started as a daemon. It also functions as a lock file to avoid the starting of nodes with the same identifier.

ndb_node_id_signal.log is a file used only in debug versions of ndbd, where it is possible to trace all incoming, outgoing, and internal messages with their data in the ndbd process.