Rank Attribute

The rank of an interface is the order in which that interface is to be preferred over other interfaces. That is, if an interface with a rank of 0 is available when a communication operation begins, it will be selected for the operation before interfaces with ranks of 1 or greater. Likewise, an available rank 1 interface will be used before interfaces with a rank of 2 or greater.

Because hpc.conf is a shared, cluster-wide configuration file, the rank specified for a given interface will apply to all nodes in the cluster.

Network ranking decisions are usually influenced by site-specific conditions and requirements. Although interfaces connected to the fastest network in a cluster are often given preferential ranking, raw network bandwidth is only one consideration. For example, an administrator might decide to dedicate one network that offers very low latency, but not the fastest bandwidth to all cluster intra-cluster communication and use a higher-capacity network for connecting the cluster to other systems.