Full bandwidth packet handling with server systems including offload processors

A rack server system for a map/reduce data processing, comprising:

• a plurality of servers arranged in a rack, and
• a plurality of offload processor modules supported on at least two of the servers, each offload processor module having an input-output (IO) port and multiple offload processors, a first offload processor module configured to execute map steps of the map/reduce data processing, and being connected directly to a second offload processor through their respective IO ports to define a midplane switch, wherein
• a second offload processor module is configured to execute reduce steps of the map/reduce data processing on data provided from the first offload processor module, and
• the first offload processor module is configured to generate virtual interrupts corresponding to the execution of the map steps.