what is a good way to do 'maintaining data distribution'

Sat Apr 12 18:16:18 CEST 2003

On of my responsibilities is to make sure that all databases 
generated on a few master machines get distributed to other machines
in a timely and reliable fashion.
Scale: machine number is around 240.
Dependence: intertwining.

Currently, I have many python scripts here and there for doing this task.
When the machines number increases and interdependence rules get more
intertwined, it becomes a headache to keep on top of things.
Perhaps I did not make full use of python to deal 
with the ever changing inter-dependence and inter-machine communication. :)
Anyway, I am looking into Erlang's way of doing this task, because of 
the built-in inter-communication at the languague-level.
The goal is to set up one system across the entire LAN network, instead
of many isolated codes here and there.

Here are two approaches that I can think of.
(1) Write down the 'dependence rules' 
    --- in analogous to an erlang makefile.
    Then, a sync-engine (in analogous to ermake.erl)
    should gather data and execute functions to maintain rule's integrity.
(2) More general way (?).
    we can have a list of entities,
    [entity1, entity2, ...]
    Each entity has its value (representing its state)
    and has associated with it a rule (one or more functions) which may
    depend on other entities.
    ---> sort of like a Spreadsheet model.
    If the value of one entity gets changed, all other entities
    that depend on it will be updated too.
(1) is straightforward to do since ermake is an example.

I don't know Erlang deep enough to know
how to express (2) in Erlang. 

Any suggestions are appreciated. 
If anyone on this list has already such modules
(either ready-to-go (1) or example of (2)) that you don't
mind sharing, it would spare me more time to play the game of GO :-)


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