From: ara.t.howard@...
Date: 2007-03-03T01:37:49+09:00
Subject: Re: [ANN] rq-3.0.0 : ruby queue gets gem'd

On Sat, 3 Mar 2007, Jeremy Hinegardner wrote:

>
> Yeah right, I learn someting new every time you post :-).  Especially
> this time.
>

heh, me too - i'm amazed someone actually insalls and looks at what it does!
;-)

>
> Ah, I was thinking the gem would be what you would install on each machine
> in the cluster.  I'm flip flopped, thinking each machine in the cluster
> would have local copies of all the libs/applications/etc that it would need
> to run the cluters jobs, but instead each machine in the cluster is more
> barebones and the common apps/libs/etc are all from the NFS location.
>

right.  but that's not to say one wouldn't flip flop - if you had net:ssh or
capistrano or puppet installed then a per node installation would be fine.  on
the otherhand, why?  it's do dang easy to upgrade when there is one ruby to
rule them all sitting on nfs, and it's not to say each node would also have a
local ruby, but it's not required.  for instance, on our cluster all we need
to do to add a node from scratch is

   - build new redhat box.  5-15 min.
   - add user account, in our case it's cfadmin
   - mount nfs drive
   - edit .bashrc so PATH=/nfs/bin:$PATH
   - rq /nfs/q cron start

done.  the node is a node forever, even across reboots.

>
> Maybe a bad assumption on my part, after a successful build I would think it
> would blow away the dross.  Maybe if there are error/warning it leaves it
> around.
>

no, you're right.  i'll add that functionality.

> This is probably the most complex gem install I've seen, I'll have to dig
> through it and see how it all works :-).

the rmagick gem is even crazier!  all rq does that's weird is to install it's
own local copy of sqlite and sqlite-ruby into it's lib dir.  the bin script
alters it's environment (PATH/LD_LIBRARY_PATH) on startup such that the local
sqlite and sqlite-ruby will be the ones used.  so i don't clobber any local
sqlite installation, don't care if you have another version installed, don't
care if you've altered you libpath to point some crazy place, it just works (i
think ;-)).

seriously though, i'm really open to suggestion because this was chore to
setup!

ciao.

-a
-- 
be kind whenever possible... it is always possible.
- the dalai lama