# Rq-2.3.2

**URL:** <https://www.ruby-forum.com/t/rq-2-3-2/94332>\
**Category:** Ruby\
**Created:** [April 28, 2006, 11:38pm UTC](https://www.ruby-forum.com/t/rq-2-3-2/94332 "2006-04-28T23:38:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [April 28, 2006, 11:38pm UTC](https://www.ruby-forum.com/t/rq-2-3-2/94332/1 "2006-04-28T23:38:23Z")

</div>

NAME  
rq v2.3.2

SYNOPSIS  
rq (queue | export RQ\_Q=q) mode [mode\_args]\* [options]\*

URIS

[http://raa.ruby-lang.org/project/rq/](http://raa.ruby-lang.org/project/rq/)  
[http://codeforpeople.com/lib/ruby/rq/rq-2.3.2/README](http://codeforpeople.com/lib/ruby/rq/rq-2.3.2/README)  
[Linux Clustering with Ruby Queue: Small Is Beautiful | Linux Journal](http://www.linuxjournal.com/article/7922)

DESCRIPTION  
ruby queue (rq) is a zero-admin zero-configuration tool used to  
create  
instant linux clusters. rq requires only a central nfs filesystem in  
order  
to manage a simple sqlite database as a distributed priority work  
queue.  
this simple design allows researchers to install and configure, in  
only a  
few minutes and without root privileges, a robust linux cluster  
capable of  
distributing processes to many nodes - bringing dozens of powerful  
cpus to  
their knees with a single blow. clearly this software should be kept  
out of  
the hands of free radicals, seti enthusiasts, and one mr. j safran.

the central concept of rq is that n nodes work in isolation to pull  
jobs  
from an centrally mounted nfs priority work queue in a synchronized  
fashion.  
the nodes have absolutely no knowledge of each other and all  
communication  
is done via the queue meaning that, so long as the queue is available  
via  
nfs and a single node is running jobs from it, the system will  
continue to  
process jobs. there is no centralized process whatsoever - all nodes  
work  
to take jobs from the queue and run them as fast as possible. this  
creates  
a system which load balances automatically and is robust in face of  
node  
failures.

although the rq system is simple in it’s design it features powerful  
functionality such as priority management, predicate and sql query ,  
compact  
streaming command-line processing, programmable api, hot-backup, and  
input/capture of the stdin/stdout/stderr io streams of remote jobs.  
to date  
rq has had no reported runtime failures and is in operation at dozens  
of  
research centers around the world.

enjoy.

-a

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<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [May 3, 2006, 7:08pm UTC](https://www.ruby-forum.com/t/rq-2-3-2/94332/2 "2006-05-03T19:08:28Z")

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I couldn’t find the changes list. What is new in this version?

Guillaume.

Le 28 avr. 06, à 17:36, Ara.T.Howard a écrit :

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**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [May 3, 2006, 7:09pm UTC](https://www.ruby-forum.com/t/rq-2-3-2/94332/3 "2006-05-03T19:09:33Z")

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On Sat, 29 Apr 2006, Guillaume M. wrote:

> I couldn’t find the changes list. What is new in this version?
> 
> Guillaume.

sorry. here you go

[http://www.codeforpeople.com/lib/ruby/rq/rq-2.3.2/HISTORY](http://www.codeforpeople.com/lib/ruby/rq/rq-2.3.2/HISTORY)

* * *

2.3.2:  
- added ‘rq q io’ command  
- streamlined ‘rq q status’ output considerably  
- fixed few small bugs in util.rb  
- patched yaml inline behaviour for syck in 1.8.4. backward  
compatible with  
older ruby versions - at least through 1.8.2.  
- changed naming scheme for rotation and added automatic attempt to  
compress  
the rotation  
- made shutdown via ctrl-c when running from commandline (as  
opposed to  
daemon) quieter  
- fixed a few bad exit codes, for example creating a queue exited  
with  
$?==1, it is now correctly 0  
- added support for job stdin to be provided and stdout/stderr  
captured.  
for instance

```
     rq queue submit cat --stdin=input_for_cat.txt

     cat input_for_cat.txt | rq queue submit cat --stdin=-

     rq queue submit cat --stdin=- < input_for_cat.txt

   stdout and stderr are stored in the queue directory in a file 

```

named by  
jid.  
- changed behaviour of reading jobs from stdin: _ **IMPORTANT** _ :  
it’s now  
**REQUIRED** to provide a ‘-’ as the argument for any command  
that should  
read from stdin. for instance one would use

```
     rq queue submit - < joblist
   or
     jobgenerator.rb | rq queue submit -

   vs the old

     rq queue submit < joblist
   or
     jobgenerator.rb | rq queue submit

   the distiction was added to make running submissions from 

```

scripts/cron  
(where STDIN.tty? == false) easier and providing the job stdinput  
on stdin  
possible.  
- added a restart mode to restart a feeder : rq q restart  
- modes shutdown, stop, and restart now return a non-zero exit code  
if they  
fail to signal the feeder, zero otherwise  
- fixed bug with restart mode whereby re-exec failed due to falsely  
thinking  
pid was locked (it is - but only by the current process!)  
- added default bin dir underneath q dir. this dir is added to the  
path  
before excuting commands to it’s an easy place to put things  
where they’ll  
be found

the biggest change is the ability to provide jobs stdin at submit time  
and to  
capture their stdout/stderr. for instance you can now do this

rq q submit cat --stdin=/etc/passwd

or

find | grep \*geo.tif | rq q submit geolocate.rb --stdin=-

to submit jobs that take stdin. the stdin is squirled away in the q  
dir.  
later, when the job is run, the stdout and stderr are captured in the  
same  
way. so, in the above example, if the submitted job had jid=42 you’d  
have

q/stdin/42 # the stdin provided

before the job was run and

q/stdin/42  
q/stdout/42  
q/stderr/42

once the job was set running. this is extrememly cool since you can do

tail -F q/stderr/42

to monitor a process on a remote node.

cheers.

-a