Configuring MySQL Cluster Send Buffer Parameters-opracowanie

Configuring MySQL Cluster Send Buffer Parameters
Formerly, the NDB kernel employed a send buffer whose size was fixed at 2MB for each node in the
cluster, this buffer being allocated when the node started. Because the size of this buffer could not
be changed after the cluster was started, it was necessary to make it large enough in advance to
accommodate the maximum possible load on any transporter socket. However, this was an inefficient
use of memory, since much of it often went unused, and could result in large amounts of resources
being wasted when scaling up to many API nodes.
This problem was eventually solved (in MySQL Cluster NDB 7.0) by employing a unified send buffer
whose memory is allocated dynamically from a pool shared by all transporters. This means that the
size of the send buffer can be adjusted as necessary. Configuration of the unified send buffer can
accomplished by setting the following parameters:
• TotalSendBufferMemory. This parameter can be set for all types of MySQL Cluster nodes—
that is, it can be set in the [ndbd], [mgm], and [api] (or [mysql]) sections of the config.ini
file. It represents the total amount of memory (in bytes) to be allocated by each node for which
it is set for use among all configured transporters. If set, its minimum is 256KB; the maximum is
4294967039.
... zobacz całą notatkę