One fun thing is that xargs supports parallelization.

    -P max-procs
    Run up to max-procs processes at a time; the default is 1.
    If max-procs is 0, xargs will run as many processes as
    possible at a time.  Use the -n option with -P; otherwise
    chances are that only one exec will be done.

    -n max-args
    Use at most max-args arguments per command line.
    Fewer than max-args arguments will be used if the size
    (see the -s option) is exceeded, unless the -x option is
    given, in which case xargs will exit.

So here is a "map/reduce" job which takes the log files in a directory and processes them in parallel on eight CPUs, then combines the results.

    find . -name "*.log" | sort | xargs -n 1 -P 8 agg_stats.py | sort | merge_periods.py