Spec-Zone .ru
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TCP/IP is the default transport mechanism for all connections between nodes in a MySQL Cluster. Normally it is not necessary to define TCP/IP connections; MySQL Cluster automatically sets up such connections for all data nodes, management nodes, and SQL or API nodes.
For an exception to this rule, see Section 17.3.2.9, "MySQL Cluster TCP/IP Connections Using Direct Connections".
To override the default connection parameters, it is necessary to define a connection using one or more [tcp]
sections in the config.ini
file. Each [tcp]
section explicitly defines a TCP/IP connection between two MySQL Cluster nodes,
and must contain at a minimum the parameters NodeId1
and NodeId2
, as well as any connection parameters to override.
It is also possible to change the default values for these parameters by setting them in the [tcp default]
section.
Any [tcp]
sections in the config.ini
file should be listed last, following all other sections in the file.
However, this is not required for a [tcp default]
section. This requirement is
a known issue with the way in which the config.ini
file is read by the MySQL
Cluster management server.
Connection parameters which can be set in [tcp]
and [tcp
default]
sections of the config.ini
file are listed here:
To identify a connection between two nodes it is necessary to provide their node IDs in the [tcp]
section of the configuration file. These are the same unique NodeId
(or Id
) values for each of these
nodes as described in Section
17.3.2.7, "Defining SQL and Other API Nodes in a MySQL Cluster".
Effective Version | Type/Units | Default | Range/Values |
---|---|---|---|
NDB 7.3.0 | name or IP address | [none] | ... |
Restart Type: N |
Effective Version | Type/Units | Default | Range/Values |
---|---|---|---|
NDB 7.3.0 | name or IP address | [none] | ... |
Restart Type: N |
The HostName1
and HostName2
parameters can
be used to specify specific network interfaces to be used for a given TCP connection between two
nodes. The values used for these parameters can be hostnames or IP addresses.
When more than this many unsent bytes are in the send buffer, the connection is considered overloaded.
This parameter can be used to determine the amount of unsent data that must be present in the send buffer before the connection is considered overloaded. See Section 17.3.2.12, "Configuring MySQL Cluster Send Buffer Parameters", for more information.
TCP transporters use a buffer to store all messages before performing the send call to the operating system. When this buffer reaches 64KB its contents are sent; these are also sent when a round of messages have been executed. To handle temporary overload situations it is also possible to define a bigger send buffer.
If this parameter is set explicitly, then the memory is not dedicated to each transporter; instead,
the value used denotes the hard limit for how much memory (out of the total available memory—that
is, TotalSendBufferMemory
) that may be used by a single transporter.
For more information about configuring dynamic transporter send buffer memory allocation in MySQL
Cluster, see Section
17.3.2.12, "Configuring MySQL Cluster Send Buffer Parameters".
The default size of the send buffer is 2MB, which is the size recommended in most situations. The minimum size is 64 KB; the theoretical maximum is 4 GB.
Effective Version | Type/Units | Default | Range/Values |
---|---|---|---|
NDB 7.3.0 | boolean | [see text] | true, false |
Restart Type: N |
To be able to retrace a distributed message datagram, it is necessary to identify each message. When
this parameter is set to Y
, message IDs are transported over the
network. This feature is disabled by default in production builds, and enabled in -debug
builds.
Effective Version | Type/Units | Default | Range/Values |
---|---|---|---|
NDB 7.3.0 | boolean | false | true, false |
Restart Type: N |
This parameter is a boolean parameter (enabled by setting it to Y
or
1
, disabled by setting it to N
or 0
). It is disabled by default. When it is enabled, checksums for all
messages are calculated before they placed in the send buffer. This feature ensures that messages
are not corrupted while waiting in the send buffer, or by the transport mechanism.
This formerly specified the port number to be used for listening for connections from other nodes.
This parameter should no longer be used; use the ServerPort
data node configuration parameter for this purpose
instead.
Specifies the size of the buffer used when receiving data from the TCP/IP socket.
The default value of this parameter is 2MB. The minimum possible value is 16KB; the theoretical maximum is 4GB.
Effective Version | Type/Units | Default | Range/Values |
---|---|---|---|
NDB 7.3.0 | unsigned | 70080 | 1 - 2G |
NDB 7.3.1 | unsigned | 0 | 0 - 2G |
Restart Type: N |
Determines the size of the receive buffer set during TCP transporter initialization. Prior to MySQL Cluster NDB 7.3.1, the default was 70080 and the minimum was 1. In MySQL Cluster NDB 7.3.1 and later, the default and minimum value is 0, which allows the operating system or platform to set this value. The default is recommended for most common usage cases.
Effective Version | Type/Units | Default | Range/Values |
---|---|---|---|
NDB 7.3.0 | unsigned | 71540 | 1 - 2G |
NDB 7.3.1 | unsigned | 0 | 0 - 2G |
Restart Type: N |
Determines the size of the send buffer set during TCP transporter initialization. Prior to MySQL Cluster NDB 7.3.1, the default was 71540 and the minimum was 1. In MySQL Cluster NDB 7.3.1 and later, the default and minimum value is 0, which allows the operating system or platform to set this value. The default is recommended for most common usage cases.