Multi thread awk command for faster performance Post: 302632149

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Top Forums Shell Programming and Scripting Multi thread awk command for faster performance Post 302632149 by drl on Sunday 29th of April 2012 09:50:03 AM

04-29-2012

Registered User

Hi.

Quote:

A thread is a lightweight process. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process. Multiple threads can exist within the same process and share resources such as memory, while different processes do not share these resources. -- excerpt from http://en.wikipedia.org/wiki/Thread_(computing)

Here is a sample use of GNU parallel that counts file contents with wc:

Code:

#!/usr/bin/env bash

# @(#) s1	Demonstrate multiple processes simultaneously, with "GNU parallel".

pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C parallel

pl " Structure of directories:"
tree d1 d2

pl " Results of parallel processes:"
ls d1/* d2/* |
grep txt |
parallel --ungroup 'echo -n job {#}, process $$", wc = "; wc {}' |
align

exit 0

producing:

Code:

% ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 2.6.26-2-amd64, x86_64
Distribution        : Debian GNU/Linux 5.0.8 (lenny) 
bash GNU bash 3.2.39
parallel GNU parallel 20111122

-----
 Structure of directories:
d1
|-- a.txt
|-- b.txt
|-- binary-1.exe
`-- c.txt
d2
|-- frog-town.jpg
|-- x.txt
`-- y.txt

0 directories, 7 files

-----
 Results of parallel processes:
job 1, process 27495, wc =  4  16   70 d1/a.txt
job 2, process 27515, wc = 16  16  123 d1/b.txt
job 3, process 27535, wc = 26 265 1464 d1/c.txt
job 4, process 27555, wc =  4  16   70 d2/x.txt
job 5, process 27575, wc = 16  16  123 d2/y.txt

Each one of the tasks was run as a separate process. The calling sequence for parallel is complex, so some experimentation might be useful. I have not tried it, but I think parallel claims to be able to utilize different computers for tasks.

The code for the (perl) parallel script is at GNU Parallel - GNU Project - Free Software Foundation

Best wishes ... cheers, drl

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LEARN ABOUT DEBIAN

parallel-nuke

PARALLEL-NUKE(1)														  PARALLEL-NUKE(1)

NAME

       parallel-nuke - kill a bunch of processes on a set of machines

SYNOPSIS

       parallel-nuke [OPTIONS] -h hosts.txt pattern

DESCRIPTION

       pssh provides a number of commands for executing against a group of computers, using SSH. It's most useful for operating on clusters of
       homogenously-configured hosts.

       The parallel-nuke command is useful when you want to kill a bunch of processes on a set of machines.

OPTIONS

       -h --hosts
	   hosts file (each line "host[:port] [user]")

       -l --user
	   username (OPTIONAL)

       -p --par
	   max number of parallel threads (OPTIONAL)

       -o --outdir
	   output directory for stdout files (OPTIONAL)

       -e --errdir
	   output directory for stderr files (OPTIONAL)

       -t --timeout
	   timeout (secs) (-1 = no timeout) per host (OPTIONAL)

       -O --options
	   SSH options (OPTIONAL)

       -v --verbose
	   turn on warning and diagnostic messages (OPTIONAL)

EXAMPLE

       For example, suppose you've got a bunch of java processes running on three nodes that you'd like to nuke (let's use the three machines from
       the pssh example). Here you would do the following:

	   # parallel-nuke -h ips.txt -l irb2 java
	   Success on 128.112.152.122:22
	   Success on 18.31.0.190:22
	   Success on 128.232.103.201:22

ENVIRONMENT

       All four programs take similar sets of options. All of these options can be set using the following environment variables:

       o   PSSH_HOSTS
       o   PSSH_USER
       o   PSSH_PAR
       o   PSSH_OUTDIR
       o   PSSH_VERBOSE
       o   PSSH_OPTIONS

SEE ALSO

       parallel-ssh(1), parallel-scp(1), parallel-slurp(1), parallel-rsync(1), ssh(1)

AUTHOR

       Brent N. Chun <bnc@theether.org>

COPYING

       Copyright: 2003, 2004, 2005, 2006, 2007 Brent N. Chun

NOTES

	1. bnc@theether.org
	   mailto:bnc@theether.org

								    03/30/2009							  PARALLEL-NUKE(1)