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
is assumed for both.
-
Version (or later) NDB 8.4.0 Type or units unsigned Default [...] Range 1 - 255 Restart Type Initial System Restart: Requires a complete shutdown of the cluster, wiping and restoring the cluster file system from a backup, and then restarting the cluster. (NDB 8.4.0)
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.
NoteData node IDs must be less than 145. 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 144.
The use of the
Id
parameter for identifying management nodes is deprecated in favor ofNodeId
. AlthoughId
continues to be supported for backward compatibility, it now generates a warning and is subject to removal in a future version of NDB Cluster. -
Version (or later) NDB 8.4.0 Type or units unsigned Default [...] Range 1 - 255 Restart Type Initial System Restart: Requires a complete shutdown of the cluster, wiping and restoring the cluster file system from a backup, and then restarting the cluster. (NDB 8.4.0)
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.
NoteData node IDs must be less than 145. 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 144.
NodeId
is the preferred parameter name to use when identifying management nodes. Although the olderId
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. -
Version (or later) NDB 8.4.0 Type or units name Default [...] Range ... Deprecated Yes (in NDB 7.5) Restart Type System Restart: Requires a complete shutdown and restart of the cluster. (NDB 8.4.0)
This refers to the
Id
set for one of the computers defined in a[computer]
section of theconfig.ini
file.ImportantThis parameter is deprecated, and is subject to removal in a future release. Use the
HostName
parameter instead. -
Version (or later) NDB 8.4.0 Type or units unsigned Default 1186 Range 0 - 64K Restart Type System Restart: Requires a complete shutdown and restart of the cluster. (NDB 8.4.0)
This is the port number on which the management server listens for configuration requests and management commands.
The node ID for this node can be given out only to connections that explicitly request it. A management server that requests “any” node ID cannot use this one. This parameter can be used when running multiple management servers on the same host, and
HostName
is not sufficient for distinguishing among processes.-
Version (or later) NDB 8.4.0 Type or units name or IP address Default [...] Range ... Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
Specifying this parameter defines the hostname of the computer on which the management node is to reside. Use
HostName
to specify a host name other thanlocalhost
. -
Version (or later) NDB 8.4.0 Type or units integer Default 0 Range 0 - 16 Restart Type System Restart: Requires a complete shutdown and restart of the cluster. (NDB 8.4.0)
Assigns a management node to a specific availability domain (also known as an availability zone) within a cloud. By informing
NDB
which nodes are in which availability domains, performance can be improved in a cloud environment in the following ways:If requested data is not found on the same node, reads can be directed to another node in the same availability domain.
Communication between nodes in different availability domains are guaranteed to use
NDB
transporters' WAN support without any further manual intervention.The transporter's group number can be based on which availability domain is used, such that also SQL and other API nodes communicate with local data nodes in the same availability domain whenever possible.
The arbitrator can be selected from an availability domain in which no data nodes are present, or, if no such availability domain can be found, from a third availability domain.
LocationDomainId
takes an integer value between 0 and 16 inclusive, with 0 being the default; using 0 is the same as leaving the parameter unset. -
Version (or later) NDB 8.4.0 Type or units {CONSOLE|SYSLOG|FILE} Default FILE: filename=ndb_nodeid_cluster.log, maxsize=1000000, maxfiles=6 Range ... Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
This parameter specifies where to send cluster logging information. There are three options in this regard—
CONSOLE
,SYSLOG
, andFILE
—withFILE
being the default:CONSOLE
outputs the log tostdout
:CONSOLE
SYSLOG
sends the log to asyslog
facility, possible values being one ofauth
,authpriv
,cron
,daemon
,ftp
,kern
,lpr
,mail
,news
,syslog
,user
,uucp
,local0
,local1
,local2
,local3
,local4
,local5
,local6
, orlocal7
.NoteNot 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.The default log file name used in such cases is
ndb_
.nodeid
_cluster.logmaxsize
: 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, whereN
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 isFILE:filename=ndb_
, wherenode_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
-
Version (or later) NDB 8.4.0 Type or units 0-2 Default 1 Range 0 - 2 Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
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 is never used as an arbitrator.1
: The node has high priority; that is, it is preferred as an arbitrator over low-priority nodes.2
: Indicates a low-priority node which is 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 theArbitration
parameter in the[ndbd default]
section of theconfig.ini
global configuration file. SettingArbitration
causes any settings forArbitrationRank
to be disregarded. -
Version (or later) NDB 8.4.0 Type or units milliseconds Default 0 Range 0 - 4294967039 (0xFFFFFEFF) Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
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.
-
Version (or later) NDB 8.4.0 Type or units path Default . Range ... Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
This specifies the directory where output files from the management server are 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 forLogDestination
, as discussed previously in this section.)The default value for this parameter is the directory in which ndb_mgmd is located.
-
Version (or later) NDB 8.4.0 Type or units unsigned Default [...] Range 0 - 64K Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
This parameter specifies the port number used to obtain statistical information from an NDB Cluster management server. It has no default value.
-
Version (or later) NDB 8.4.0 Type or units boolean Default false Range true, false Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
Use WAN TCP setting as default.
-
Version (or later) NDB 8.4.0 Type or units string Default [...] Range ... Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
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) orRR
(round robin). The policy value is followed optionally by the priority (an integer). -
Version (or later) NDB 8.4.0 Type or units bytes Default 0 Range 0 - 32G Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
This parameter specifies the amount of transporter send buffer memory to allocate in addition to any that has been set using
TotalSendBufferMemory
,SendBufferMemory
, or both. -
Version (or later) NDB 8.4.0 Type or units boolean Default false Range ... Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
If this parameter is set to
true
, a client, once connected to this management node, must be authenticated using TLS before the connection can be used for anything else. -
Version (or later) NDB 8.4.0 Type or units bytes Default 0 Range 256K - 4294967039 (0xFFFFFEFF) Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
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 25.4.3.14, “Configuring NDB Cluster Send Buffer Parameters”.
-
Version (or later) NDB 8.4.0 Type or units milliseconds Default 1500 Range 100 - 4294967039 (0xFFFFFEFF) Restart Type Node Restart: Requires a rolling restart of the cluster. (NDB 8.4.0)
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.
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 25.2.7.10, “Limitations Relating to Multiple NDB Cluster Nodes”.
Restart types. Information about the restart types used by the parameter descriptions in this section is shown in the following table:
Table 25.8 NDB Cluster restart types
Symbol | Restart Type | Description |
---|---|---|
N | Node | The parameter can be updated using a rolling restart (see Section 25.6.5, “Performing a Rolling Restart of an NDB Cluster”) |
S | System | All cluster nodes must be shut down completely, then restarted, to effect a change in this parameter |
I | Initial | Data nodes must be restarted using the
--initial option |