Abstract: Node locations in the topology of a cluster computer server are designated as input/output (I/O) nodes that provide input and output for the cluster computer server. Examples of I/O nodes include network nodes that provide an interface for the cluster computer server to an external network, and storage nodes that provide access to storage devices for the cluster compute server. The I/O nodes are configured to analyze received messages and identify whether the message is targeted to the receiving I/O node or to another node of the cluster compute server. Those messages targeted to the I/O node are provided to a processing module of the I/O node for processing.