PDSH (Parallel Distributed SHell) issues commands to groups of hosts in parallel. It is a rewrite of IBM's dsh implementation done at LLNL.
pdsh is a variant of the rsh(1) command. Unlike rsh(1), which runs commands on a single remote host, pdsh can run multiple remote commands in parallel. pdsh uses a "sliding window" (or fanout) of threads to conserve resources on the initiating host while allowing some connections to time out.