NodeId1

To identify a connection between two nodes it is necessary to provide node identifiers for each of them, as NodeId1 and NodeId2.

NodeId2

To identify a connection between two nodes it is necessary to provide node identifiers for each of them, as NodeId1 and NodeId2.

Host1SciId0

This identifies the SCI node ID on the first Cluster node (identified by NodeId1).

Host1SciId1

It is possible to set up SCI Transporters for failover between two SCI cards which then should use separate networks between the nodes. This identifies the node ID and the second SCI card to be used on the first node.

Host2SciId0

This identifies the SCI node ID on the second Cluster node (identified by NodeId2).

Host2SciId1

When using two SCI cards to provide failover, this parameter identifies the second SCI card to be used on the second node.

HostName1

The HostName1 and HostName2 parameters can be used to specify specific network interfaces to be used for a given SCI connection between two nodes. The values used for these parameters can be host names or IP addresses.

HostName2

The HostName1 and HostName2 parameters can be used to specify specific network interfaces to be used for a given SCI connection between two nodes. The values used for these parameters can be host names or IP addresses.

SharedBufferSize

Each SCI transporter has a shared memory segment used for communication between the two nodes. Setting the size of this segment to the default value of 1MB should be sufficient for most applications. Using a smaller value can lead to problems when performing many parallel inserts; if the shared buffer is too small, this can also result in a crash of the ndbd process.

SendLimit

A small buffer in front of the SCI media stores messages before transmitting them over the SCI network. By default, this is set to 8KB. Our benchmarks show that performance is best at 64KB but 16KB reaches within a few percent of this, and there was little if any advantage to increasing it beyond 8KB.

SendSignalId

To trace a distributed message it is necessary to identify each message uniquely. 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.

Checksum

This parameter is a boolean value, and is disabled by default. When Checksum is enabled, checksums are calculated for all messages before they are placed in the send buffer. This feature prevents messages from being corrupted while waiting in the send buffer. It also serves as a check against data being corrupted during transport.

OverloadLimit

When more than this many unsent bytes are in the send buffer, the connection is considered overloaded. See Section 18.3.3.13, “Configuring NDB Cluster Send Buffer Parameters”, for more information.