ndbd

SYNOPSIS
       ndbd options

DESCRIPTION
       ndbd is the process that is used to handle all the data in tables using
       the NDB Cluster storage engine. This is the process that empowers a
       data node to accomplish distributed transaction handling, node
       recovery, checkpointing to disk, online backup, and related tasks.

       In a MySQL Cluster, a set of ndbd processes cooperate in handling data.
       These processes can execute on the same computer (host) or on different
       computers. The correspondences between data nodes and Cluster hosts is
       completely configurable.

       The following list describes command options specific to the MySQL
       Cluster data node program ndbd. For options common to all NDBCLUSTER
       programs, see Section 17.6.2, "Options Common to MySQL Cluster
       Programs".

       o  --bind-address

          +--------------------+---------------------+
          |Version Introduced  | 5.0.29              |
          +--------------------+---------------------+
          |Command Line Format | --bind-address=name |
          +--------------------+---------------------+
          |Value Set           | [nested table]*     |
          +--------------------+---------------------+

       *[nested table]
       +--------+--------+
       |Type    | string |
       +--------+--------+
       |Default |        |
       +--------+--------+
       Causes ndbd to bind to a specific network interface (host name or IP
       address). This option has no default value.

       This option was added in MySQL 5.0.29.

       o  --daemon, -d

          +--------------------+-----------------+
          |Command Line Format | --daemon        |
          +--------------------+-----------------+
          |Value Set           | [nested table]* |
          +--------------------+-----------------+

       *[nested table]
       +--------+---------+
       |Type    | boolean |
       +--------+---------+
       |Default | TRUE    |

       *[nested table]
       +--------+---------+
       |Type    | boolean |
       +--------+---------+
       |Default | FALSE   |
       +--------+---------+
       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 Cluster file system and all redo log
       files to be re-created. These circumstances are listed here:

          o  When performing a software upgrade which has changed the contents
             of any files.

          o  When restarting the node with a new version of ndbd.

          o  As a measure of last resort when for some reason the node restart
             or system restart repeatedly fails. In this case, be aware that
             this node can no longer be used to restore data due to the
             destruction of the data files.



          Important
          This option does not affect any backup files that have already been
          created by the affected node.  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.

       o  --initial-start

          +--------------------+-----------------+
          |Version Introduced  | 5.0.21          |
          +--------------------+-----------------+
          |Command Line Format | --initial-start |
          +--------------------+-----------------+
          |Value Set           | [nested table]* |
          +--------------------+-----------------+

       *[nested table]
       +--------+---------+
       |Type    | boolean |
       +--------+---------+
       |Default | FALSE   |
       +--------+---------+
       This option is used when performing a partial initial start of the
       cluster. Each node should be started with this option, as well as

          +--------------------+---------------------+
          |Version Introduced  | 5.0.21              |
          +--------------------+---------------------+
          |Command Line Format | --nowait-nodes=list |
          +--------------------+---------------------+
          |Value Set           | [nested table]*     |
          +--------------------+---------------------+

       *[nested table]
       +--------+--------+
       |Type    | string |
       +--------+--------+
       |Default |        |
       +--------+--------+
       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.

       This option was added in MySQL 5.0.21.

       o  --nodaemon

          +--------------------+-----------------+
          |Command Line Format | --nodaemon      |
          +--------------------+-----------------+
          |Value Set           | [nested table]* |
          +--------------------+-----------------+

       *[nested table]
       +--------+---------+
       |Type    | boolean |
       +--------+---------+
       |Default | FALSE   |
       +--------+---------+
       Instructs ndbd not to start as a daemon process. This is useful when
       ndbd is being debugged and you want output to be redirected to the
       screen.

       o  --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 17.7.2,
       "Commands in the MySQL Cluster Management Client").


       ndbd generates a set of log files which are placed in the directory
       specified by DataDir in the config.ini configuration file.

       These log files are listed below.  node_id is the node's unique
       identifier. Note that node_id represents the node's unique identifier.
       For example, ndb_2_error.log is the error log generated by the data
       node whose node ID is 2.

       o  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 - 00:20:01
          Type of error: error
          Message: Internal program error (failed ndbrequire)
          Fault ID: 2341
          Problem data: DbtupFixAlloc.cpp
          Object of reference: DBTUP (Line: 173)
          ProgramName: NDB Kernel
          ProcessID: 14909
          TraceFile: 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 [1]ndbd Error
       Messages.

       Important
       The last entry in the error log file is not necessarily the newest one
       (nor is it likely to be). Entries in the error log are not listed in
       chronological order; rather, they correspond to the order of the trace
       files as determined in the ndb_node_id_trace.log.next file (see below).
       Error log entries are thus overwritten in a cyclical and not sequential
       fashion.

       o  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.

       o  ndb_node_id_trace.log.next is the file that keeps track of the next
          internal messages with their data in the ndbd process.


       It is recommended not to use a directory mounted through NFS because in
       some environments this can cause problems whereby the lock on the .pid
       file remains in effect even after the process has terminated.

       To start ndbd, it may also be necessary to specify the host name of the
       management server and the port on which it is listening. Optionally,
       one may also specify the node ID that the process is to use.

          shell> ndbd --connect-string="nodeid=2;host=ndb_mgmd.mysql.com:1186"

       See Section 17.3.4.2, "The MySQL Cluster Connectstring", for additional
       information about this issue.  ndbd(8), describes other options for
       ndbd.

       When ndbd starts, it actually initiates two processes. The first of
       these is called the "angel process"; its only job is to discover when
       the execution process has been completed, and then to restart the ndbd
       process if it is configured to do so. Thus, if you attempt to kill ndbd
       via the Unix kill command, it is necessary to kill both processes,
       beginning with the angel process. The preferred method of terminating
       an ndbd process is to use the management client and stop the process
       from there.

       The execution process uses one thread for reading, writing, and
       scanning data, as well as all other activities. This thread is
       implemented asynchronously so that it can easily handle thousands of
       concurrent actions. In addition, a watch-dog thread supervises the
       execution thread to make sure that it does not hang in an endless loop.
       A pool of threads handles file I/O, with each thread able to handle one
       open file. Threads can also be used for transporter connections by the
       transporters in the ndbd process. In a multi-processor system
       performing a large number of operations (including updates), the ndbd
       process can consume up to 2 CPUs if permitted to do so.

       For a machine with many CPUs it is possible to use several ndbd
       processes which belong to different node groups; however, such a
       configuration is still considered experimental and is not supported for
       MySQL 5.0 in a production setting. See Section 17.10, "Known
       Limitations of MySQL Cluster".

COPYRIGHT
       Copyright 2007-2008 MySQL AB, 2009 Sun Microsystems, Inc.

       This documentation is free software; you can redistribute it and/or
       modify it only under the terms of the GNU General Public License as
       published by the Free Software Foundation; version 2 of the License.

       This documentation is distributed in the hope that it will be useful,
       but WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
       General Public License for more details.
       may already be installed locally and which is also available online at
       http://dev.mysql.com/doc/.

AUTHOR
       Sun Microsystems, Inc. (http://www.mysql.com/).



MySQL 5.0                         05/29/2009                           NDBD(8)