The parallel-ssh module and scripts implement parallelized versions of common SSH tasks including:

• Arbitrary commands over SSH (the pssh utility)
• File copying to and from remote servers over SSH (the pscp and pslurp utilities, respectively)
• Syncing files over SSH (the prsync utility)
• Forcefully killing processes over SSH (the pnuke utility)

This project utilizes the SSH binaries and libraries already installed on your system, making it ideal for administrators who do not want to manage external dependencies or for servers which need to be bootstrapped to make use of utilities (e.g. Chef, Puppet, Salt) that follow the master-agent paradigm (i.e. require agents to be installed in order to manage servers).

Original work on parallel-ssh is by Brent Chun and Andrew McNabb.

This fork of parallel-ssh implements a number of improvements, including major refactoring of the libraries to make them more modular and easier to extend and the addition of numerous extra options for more easily managing, viewing, and saving the status of command runs.

To see a list of all changes, view the ChangeLog.

One of the most useful additions to the pssh utility in particular are the --script and --sudo options:

$ pssh -h hostfile.txt --script restart_iptables.sh --sudo

These options let you run arbitrary scripts (as root, if needed) on remote hosts, without having to properly escape or make special considerations for the contents of those scripts. All that's required is that the script contain a shebang line referencing an interpreter that exists on the remote host.

All of the utilities received some new common options, some of which include the --host-regexp and --sample-size options. More information can be found by simply typing [utility] --help. (All of the help output for the commands has been reorganized and made easier to read)