NAME: 

  ruby queue - rq


SYNOPSIS:

  rq is a tool for building simple linux clusters using coordinated shared
  access to an nfs mounted priority job queue


EXAMPLE INSTALL:

  the packages/ directory contains ALL packages required to install rq.

  the file install.sh will install ALL required packages for ruby queue into
  an nfs mounted directory.  it is a simple script - feel free to read/edit.

  installed packages will include:

    - ruby-1.8.1
    - sqlite-2.8.15
    - sqlite-ruby-1.3.1
    - arrayfields-3.4.0
    - posixlock-0.0.1
    - lockfile-1.1.0
    - rq-0.1.7

  the install.sh procedure is reccomended since

    - a common nfs filesystem is required on which to store the queue anyhow

    - installing all packages into this common nfs filesystem means no
      software will be installed locally on any node which simplifies
      maintainance and the addition of new nodes to the cluster.

    - this technique implies only two requirements for any node to join the
      cluster:

        - mount the nfs filesystem

        - add a single crontab entry

    install.sh should/will not run as root so the user running it must have
    write permission (or sudo write permission) to the /nfs mounted directory:

    following are the steps for an install into the nfs mounted directory
    '/nfs'.  absolutely NO packages or files will be installed outside this
    hierachy so simply use 'rm -rf' to un-install.  
  
      - tar xvfz rq-all.tgz

      - cd rq-all/

      - ./install.sh /nfs  

    or

      - ./install.sh /nfs sudo

    if you require sudo to write to /nfs/


EXAMPLE SETUP:

  the following instructions assume your PATH has been set appropriately on
  all nodes:

    - export PATH=/nfs/bin/:$PATH

  create the queue (one node - one time only)

    - rq /nfs/queue create

  add crontab entries similar to below to keep immortal feeders alive on ALL
  nodes.  this will not start feeders every 15 mintues - it will only attempt
  to start one every 15 minutes, failing silently if one is already running.

    */15 * * * * /nfs/bin/rq /nfs/queue feed --daemon --log=/home/YOUR_USERNAME/cfq.log --quiet >/dev/null 2>&1


EXAMPLE USAGE:

  submit a command line job to the nfs mounted queue

    - rq /nfs/queue submit 'echo 42'

  submit a list of jobs from 'jobfile'.  jobfile is simply a text file with
  one command per line.  blank lines and comments (#) are ignored.

    - rq /nfs/queue submit < jobfile 

  check the status of your jobs (note that it may take cron a while to start
  feeders depending on interval used in crontab entry)

    - rq /nfs/queue status 

  for more info

    - rq help


AUTHOR:

  ara.t.howard@noaa.gov