NIS? - rsync

alvin at Maggie.Linux-Consulting.com alvin at Maggie.Linux-Consulting.com
Fri Oct 5 19:19:55 EDT 2001


hi ya

ping master1 .... if its up... copy from it... if its down
ping master2 .... if its up... copy from it... or check why both are down

this way, you only need to maintain "master1" passwd/shadow/hosts files

just need everyone to have the descipline to only change passwd
on master1 or master2 ... and the rest of the nodes will
hourly or every 10 minutes check fro new files ..
	- i prefer a pull of new data... than  a push from the master

c ya
alvin


On Fri, 5 Oct 2001, Steven Timm wrote:

> The rsync script is a good idea and something we are thinking
> of implementing--only problem is...how do you handle the
> situation when a node happens to be down during a push?
> 
> Steve
> 
> 
> ------------------------------------------------------------------
> Steven C. Timm (630) 840-8525  timm at fnal.gov  http://home.fnal.gov/~timm/
> Fermilab Computing Division/Operating Systems Support
> Scientific Computing Support Group--Computing Farms Operations
> 
> On Fri, 5 Oct 2001, David Bussenschutt wrote:
> 
> > Slight side-bar here, but I think it relates:
> >
> > My chain of thought:
> >
> > 1) everyone agrees NIS works (even if it is arguable about the speed,
> > reliability, security etc)
> > 2) everyone agrees that it can/cause have problems in some situations -
> > especially beowulf speed related ones.
> > 3) the speed has to do with the synchronisation delays inherent in a
> > bidirectional on-the-fly network daemon approach like NIS
> > 4) many people prefer the files approach for speed/simplicity (ie to avoid
> > problems in 3).
> > 5) In a beowulf cluster, passwords shouldn't be changed on nodes, so a
> > server push password system is all that's required -hence the files
> > approach in 4).
> > 6) why not have the best of both worlds?   What we need is a little daemon
> > on the server that pushes the passwd/shadow/group/etc files to the clients
> > over a ssh link whenever the respective file is modified on the server.
> > 7) How I suggest implementing this:
> >
> > The nieve/simple approach:
> > set up the client so that root can ssh to them without a password (I
> > suggest a ~/.ssh/authorisedkeys2 file amd a ~/.ssh/known_hosts2 file)
> > root crontab entries that run the following commands periodically (as
> > often as you require - depending on how much password latency you can live
> > with)
> > # first client
> > /usr/bin/rsync -ae 'ssh -x' --rsync-path='/usr/bin' /etc/passwd
> > root at client1
> > /usr/bin/rsync -ae 'ssh -x' --rsync-path='/usr/bin' /etc/shadow
> > root at client1
> > /usr/bin/rsync -ae 'ssh -x' --rsync-path='/usr/bin' /etc/group
> > root at client1
> > # second client
> > /usr/bin/rsync -ae 'ssh -x' --rsync-path='/usr/bin' /etc/passwd
> > root at client2
> > /usr/bin/rsync -ae 'ssh -x' --rsync-path='/usr/bin' /etc/shadow
> > root at client2
> > /usr/bin/rsync -ae 'ssh -x' --rsync-path='/usr/bin' /etc/group
> > root at client2
> > # etc
> >
> >
> > The improved aproach (a perl program i just wrote - tell me what u think?
> >
> > ):
> >
> >
> > --------------------------------------------------------------------
> > David Bussenschutt          Email: D.Bussenschutt at mailbox.gu.edu.au
> > Senior Computing Support Officer & Systems Administrator/Programmer
> > Location: Griffith University. Information Technology Services
> >            Brisbane Qld. Aust.  (TEN bldg. rm 1.33) Ph: (07)38757079
> > --------------------------------------------------------------------
> >
> >
> >
> >
> > Donald Becker <becker at scyld.com>
> > Sent by: beowulf-admin at beowulf.org
> > 10/05/01 10:32 AM
> >
> >
> >         To:     Tim Carlson <tim.carlson at pnl.gov>
> >         cc:     Greg Lindahl <lindahl at conservativecomputer.com>, beolist
> > <beowulf at beowulf.org>
> >         Subject:        Re: NIS?
> >
> >
> > On Thu, 4 Oct 2001, Tim Carlson wrote:
> > > On Thu, 4 Oct 2001, Greg Lindahl wrote:
> > >
> > > > BTW, by slaves, do you mean "slave servers" or "clients"? There's a
> > > > big difference. Having lots of slave servers means a push takes a
> > > > while, but queries are uniformly fast.
> > >
> > > I meant clients.
> > > 1 master, 50 clients.
> > > The environment on the Sun side wasn't a cluster. 50 desktops.
> >
> > Completely different cases.
> >  Workstation clients send a few requests to the NIS server at random
> > times.
> >  Cluster nodes will send a bunch of queries simultaneously.
> >
> > > Never had complaints about authentication delays. I just haven't seen
> > > these huge NIS problems that everybody complains about.
> >
> > The problems are not failures, just dropped and delayed responses.  A
> > user might not notice an occasional ten second delay.  When even trivial
> > cluster jobs took ten seconds, you'll notice.
> >
> > > If you were running
> > > 1000 small jobs in a couple of minutes I could imagine having problems
> > > authenticating against any non-local mechanism.
> >
> > Hmmm, a reasonable goal is running a small cluster-wide job every
> > second.  I suspect the NIS delays alone take longer than one second with
> > just a few nodes.
> >
> > > Our current cluster builds use http://rocks.npaci.edu/ for clustering
> > > software. This system uses NIS.  I know it is odd to hear of any other
> > > system than Scyld on this list,  but we have had good luck with NPACI
> > > Rocks.
> >
> > We don't discourage discussions about other _Beowulf_ systems on this
> > list.  We have thought extensively about the technical challenges
> > building and running clusters, and are more than willing to share our
> > experiences and solutions.
> >
> > Donald Becker becker at scyld.com
> > Scyld Computing Corporation                              http://www.scyld.com
> > 410 Severn Ave. Suite 210                                Second Generation
> > Beowulf Clusters
> > Annapolis MD 21403 410-990-9993
> >
> >
> > _______________________________________________
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> >
> >
> >
> >
> 
> 
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