Composable computing architectures with an interconnection fabric to provide high availability and fault tolerance are described. An interconnection fabric routes packets between compute resources, memory resources, and input/output (I/O) resources. A fabric manager is coupled with the interconnection fabric to receive an I/O or memory requirement for a compute workload for a host device, and to map individual I/O or memory resources from the plurality of I/O resources to individual compute resources from the plurality of compute resource and to dynamically map individual I/O resources from the plurality of I/O resources based on received resource requests.