The [ndb_mgmd] section is used to configure
the behavior of the management server. If multiple management
servers are employed, you can specify parameters common to all
of them in an [ndb_mgmd default] section.
[mgm] and [mgm default]
are older aliases for these, supported for backward
compatibility.
All parameters in the following list are optional and assume their default values if omitted.
If neither the ExecuteOnComputer nor the
HostName parameter is present, the default
value localhost will be assumed for both.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | unsigned | [none] | 1 - 255 | IS |
Each node in the cluster has a unique identity. For a management node, this is represented by an integer value in the range 1 to 255, inclusive. This ID is used by all internal cluster messages for addressing the node, and so must be unique for each NDB Cluster node, regardless of the type of node.
Data node IDs must be less than 49. If you plan to deploy a large number of data nodes, it is a good idea to limit the node IDs for management nodes (and API nodes) to values greater than 48.
The use of the Id parameter for
identifying management nodes is deprecated in favor of
NodeId. Although
Id continues to be supported for backward
compatibility, it now generates a warning and is subject to
removal in a future version of NDB Cluster.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | unsigned | [none] | 1 - 255 | IS |
Each node in the cluster has a unique identity. For a management node, this is represented by an integer value in the range 1 to 255 inclusive. This ID is used by all internal cluster messages for addressing the node, and so must be unique for each NDB Cluster node, regardless of the type of node.
Data node IDs must be less than 49. If you plan to deploy a large number of data nodes, it is a good idea to limit the node IDs for management nodes (and API nodes) to values greater than 48.
NodeId is the preferred parameter name to
use when identifying management nodes. Although the older
Id continues to be
supported for backward compatibility, it is now deprecated
and generates a warning when used; it is also subject to
removal in a future NDB Cluster release.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | name | [none] | ... | S |
This refers to the Id set for one of the
computers defined in a [computer] section
of the config.ini file.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | unsigned | 1186 | 0 - 64K | S |
This is the port number on which the management server listens for configuration requests and management commands.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | name or IP address | [none] | ... | N |
Specifying this parameter defines the hostname of the
computer on which the management node is to reside. To
specify a hostname other than localhost,
either this parameter or
ExecuteOnComputer is required.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | {CONSOLE|SYSLOG|FILE} | [see text] | ... | N |
This parameter specifies where to send cluster logging
information. There are three options in this
regard—CONSOLE,
SYSLOG, and
FILE—with FILE
being the default:
CONSOLE outputs the log to
stdout:
CONSOLE
SYSLOG sends the log to a
syslog facility, possible values
being one of auth,
authpriv, cron,
daemon, ftp,
kern, lpr,
mail, news,
syslog, user,
uucp, local0,
local1, local2,
local3, local4,
local5, local6, or
local7.
Not every facility is necessarily supported by every operating system.
SYSLOG:facility=syslog
FILE pipes the cluster log output to
a regular file on the same machine. The following values
can be specified:
filename: The name of the log
file.
In NDB Cluster 7.3 and later, the default log file
name used in such cases is
ndb_
(in some older versions, the log file's default
name, used if nodeid_cluster.logFILE was specified
without also setting filename,
was logger.log.).
maxsize: The maximum size (in
bytes) to which the file can grow before logging
rolls over to a new file. When this occurs, the old
log file is renamed by appending
.N to the file name,
where N is the next
number not yet used with this name.
maxfiles: The maximum number of
log files.
FILE:filename=cluster.log,maxsize=1000000,maxfiles=6
The default value for the FILE
parameter is
FILE:filename=ndb_,
where node_id_cluster.log,maxsize=1000000,maxfiles=6node_id is the ID of
the node.
It is possible to specify multiple log destinations separated by semicolons as shown here:
CONSOLE;SYSLOG:facility=local0;FILE:filename=/var/log/mgmd
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | 0-2 | 1 | 0 - 2 | N |
This parameter is used to define which nodes can act as
arbitrators. Only management nodes and SQL nodes can be
arbitrators. ArbitrationRank can take one
of the following values:
0: The node will never be used as an
arbitrator.
1: The node has high priority; that
is, it will be preferred as an arbitrator over
low-priority nodes.
2: Indicates a low-priority node
which be used as an arbitrator only if a node with a
higher priority is not available for that purpose.
Normally, the management server should be configured as an
arbitrator by setting its ArbitrationRank
to 1 (the default for management nodes) and those for all
SQL nodes to 0 (the default for SQL nodes).
You can disable arbitration completely either by setting
ArbitrationRank to 0 on all management
and SQL nodes, or by setting the
Arbitration
parameter in the [ndbd default] section
of the config.ini global configuration
file. Setting
Arbitration causes
any settings for ArbitrationRank to be
disregarded.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | milliseconds | 0 | 0 - 4294967039 (0xFFFFFEFF) | N |
An integer value which causes the management server's responses to arbitration requests to be delayed by that number of milliseconds. By default, this value is 0; it is normally not necessary to change it.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | path | . | ... | N |
This specifies the directory where output files from the
management server will be placed. These files include
cluster log files, process output files, and the daemon's
process ID (PID) file. (For log files, this location can be
overridden by setting the FILE parameter
for LogDestination
as discussed previously in this section.)
The default value for this parameter is the directory in which ndb_mgmd is located.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | unsigned | [none] | 0 - 64K | N |
This parameter specifies the port number used to obtain statistical information from an NDB Cluster management server. It has no default value.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | boolean | false | true, false | N |
Use WAN TCP setting as default.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | string | [none] | ... | S |
Set the scheduling policy and priority of heartbeat threads for management and API nodes.
The syntax for setting this parameter is shown here:
HeartbeatThreadPriority =policy[,priority]policy: {FIFO | RR}
When setting this parameter, you must specify a policy. This
is one of FIFO (first in, first out) or
RR (round robin). The policy value is
followed optionally by the priority (an integer).
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.0 | bytes | 0 | 256K - 4294967039 (0xFFFFFEFF) | N |
This parameter is used to determine the total amount of memory to allocate on this node for shared send buffer memory among all configured transporters.
If this parameter is set, its minimum permitted value is 256KB; 0 indicates that the parameter has not been set. For more detailed information, see Section 18.3.3.13, “Configuring NDB Cluster Send Buffer Parameters”.
| Effective Version | Type/Units | Default | Range/Values | Restart Type |
|---|---|---|---|---|
| NDB 7.3.3 | milliseconds | 1500 | 100 - 4294967039 (0xFFFFFEFF) | N |
Specify the interval between heartbeat messages used to determine whether another management node is on contact with this one. The management node waits after 3 of these intervals to declare the connection dead; thus, the default setting of 1500 milliseconds causes the management node to wait for approximately 1600 ms before timing out.
This parameter was added in NDB 7.3.3. (Bug #16426805)
After making changes in a management node's configuration, it is necessary to perform a rolling restart of the cluster for the new configuration to take effect.
To add new management servers to a running NDB Cluster, it is
also necessary to perform a rolling restart of all cluster
nodes after modifying any existing
config.ini files. For more information
about issues arising when using multiple management nodes, see
Section 18.1.6.10, “Limitations Relating to Multiple NDB Cluster Nodes”.