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•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. 

• NoOfReplicas 

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This global parameter can be set only in the [ndbd default]  section, and defines the number of fragment replicas for each table stored in the cluster. This parameter also specifies the size of node groups. A node group is a set of nodes all storing the same information. 

Node groups are formed implicitly. The first node group is formed by the set of data nodes with the lowest node IDs, the next node group by the set of the next lowest node identities, and so on. By way of example, assume that we have 4 data nodes and that NoOfReplicas  is set to 2. The four data nodes have node IDs 2, 3, 4 and 5. Then the first node group is formed from nodes 2 and 3, and the second node group by nodes 4 and 5. It is important to configure the cluster in such a manner that nodes in the 

