A system comprising: a cluster of processing nodes; a reconfigurable interconnect fabric to selectively connect the processing nodes, wherein the reconfigurable interconnect fabric is configured to enable multiple concurrent connections between at least some of the processing nodes; a data storage system storing multiple configuration profiles that respectively specify different configurations of the reconfigurable interconnect fabric for subsets of the processing nodes in the cluster, wherein at least some of the different configurations provide different numbers of connections between processing nodes to provide different levels of data transfer bandwidth between pairs of processing nodes, wherein the multiple configuration profiles include a plurality of configuration profiles that respectively specify different sets of connections among a subset of the processing nodes, wherein the set of connections for each of the configuration profiles in the plurality of configuration profiles utilizes each data port of each processing node in the subset; and a management system configured to: allocate multiple different subsets of the processing nodes in the cluster such that the different subsets are separately used to concurrently perform different processing tasks of different users; concurrently use configurations from different configuration profiles for different processing tasks, wherein the different configuration profiles involve at least one of (i) different numbers of processing nodes or (ii) different connection topologies (130a-130c, 132a-c, 134a-134b) among the subset of processing nodes; select a configuration profile from among the multiple configuration profiles; use the reconfigurable interconnect fabric to set connections among a subset of the processing nodes as specified by the selected configuration profile; and provide access to the subset of the processing nodes, with connections among the subset of processing nodes as specified by the selected configuration profile, for performing a processing task. a cluster of processing nodes; a reconfigurable interconnect fabric to selectively connect the processing nodes, wherein the reconfigurable interconnect fabric is configured to enable multiple concurrent connections between at least some of the processing nodes; a data storage system storing multiple configuration profiles that respectively specify different configurations of the reconfigurable interconnect fabric for subsets of the processing nodes in the cluster, wherein at least some of the different configurations provide different numbers of connections between processing nodes to provide different levels of data transfer bandwidth between pairs of processing nodes, wherein the multiple configuration profiles include a plurality of configuration profiles that respectively specify different sets of connections among a subset of the processing nodes, wherein the set of connections for each of the configuration profiles in the plurality of configuration profiles utilizes each data port of each processing node in the subset; and a management system configured to: allocate multiple different subsets of the processing nodes in the cluster such that the different subsets are separately used to concurrently perform different processing tasks of different users; concurrently use configurations from different configuration profiles for different processing tasks, wherein the different configuration profiles involve at least one of (i) different numbers of processing nodes or (ii) different connection topologies (130a-130c, 132a-c, 134a-134b) among the subset of processing nodes; select a configuration profile from among the multiple configuration profiles; use the reconfigurable interconnect fabric to set connections among a subset of the processing nodes as specified by the selected configuration profile; and provide access to the subset of the processing nodes, with connections among the subset of processing nodes as specified by the selected configuration profile, for performing a processing task. allocate multiple different subsets of the processing nodes in the cluster such that the different subsets are separately used to concurrently perform different processing tasks of different users; concurrently use configurations from different configuration profiles for different processing tasks, wherein the different configuration profiles involve at least one of (i) different numbers of processing nodes or (ii) different connection topologies (130a-130c, 132a-c, 134a-134b) among the subset of processing nodes; select a configuration profile from among the multiple configuration profiles; use the reconfigurable interconnect fabric to set connections among a subset of the processing nodes as specified by the selected configuration profile; and provide access to the subset of the processing nodes, with connections among the subset of processing nodes as specified by the selected configuration profile, for performing a processing task.