[Beowulf] Automatically replication of directories among nodes

[Miroslav Shaltev]

On Wed, 25 Nov 2020 17:28:35 +0000
"Lux, Jim \(US 7140\) via Beowulf" <beowulf at beowulf.org> wrote:

Hi Jim,

what about glusterfs? Three nodes sounds perfect, it should eventually
heal itself even if the network is unreliable.

Cheers,
miroslav



> It’s kind of a cluster, but not exactly HPC.
> 
> What I have is 3 rPi computers, A,B, and C, and what I’d like to do
> is keep the desktop and some data directories on all of them
> synchronized.  So if on node A, I add something to A:~/Desktop, it
> (in short order) winds up in the ~/Desktop directory on the other 2
> machines.
> 
> It’s easy if I’m doing it from another computer – pdsh and similar do
> a great job turning a single command into 3 (or N).
> 
> But what if it’s on the node itself.  I thought about something like
> rsync running every second or 10 seconds, or whatever.
> 
> But maybe there’s a clever-er way. The network connection isn’t
> perfect, so a “map it to a shared network drive” approach doesn’t
> work, and there’s no guarantee that the state is the same on all
> machines (i.e. one might drop off and reset, and be way behind the
> other two).  And, the changes might come from any source (i.e. I
> can’t run all file changes through some single entry point that does
> a pdsh like “write 3 times”)
> 
> Here's a sort of use case: the three nodes are in physically
> different locations, nominally connected by a network connection that
> is unreliable.  You, user of the system, is at Node A, and in the
> course of debugging a function, decide that you need to change some
> files, so you do that, locally.  And then, by the time you get to
> Node B or C, what you did on A is already there.   Imagine some sort
> of distributed industrial control scenario, perhaps.
> 
> 
> 
> Jim Lux
> SunRISE Project Manager
> Jet Propulsion Lab
> +1(818)354-2075 (office)
> +1(818)395-2714 (cell)
> 
> 



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