

Graphs in Operations - uggedal
http://blog.lusis.org/blog/2012/03/06/graphs-in-operations/

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EzGraphs
Maven deals with dependencies related to application builds. If I understand
the article correctly, the author is suggesting a way of sanely managing
dependencies related to deployment configurations. This might include
subgraphs that represent the application builds on several nodes, but would
also reference configuration files from app servers, web servers, etc.

A first step might be to simply visualize the relationships in question. I
have used GraphViz (<http://graphviz.org/>) to this end for a number of
situations (internal corporate projects).

I think the challenge is that the relationships (edges) of the graph do not
all necessarily represent the same types of dependencies. Some would result in
compile time errors, some run time errors, some would cripple a system, and
some have little practical effect. I do like the idea of a simple declarative
system representing a dependencies between components as a graph though.

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NathanRice
This is actually an active area of research in the theory of computation, and
computational semantics. Researchers have been hard at work trying to
formulate an algebra of ubiquitous computation that can encapsulate the
spatial and temporal arrangement of mobile processes (which in this case
includes computer processes, physical processes, chemical processes, etc).
Graphs (or variants) are the structure that is being used to model these
systems. Processes are nodes (or sets of nodes) with an algebraic structure
that permits composition and formal reasoning.

For an easy-ish overview, check out: -- edit -- this was the wrong set of
slides... These are dense.

<http://www.cl.cam.ac.uk/archive/rm135/Bigraphs-Lectures.pdf>

The easy ones are here: <http://lcs.ios.ac.cn/lectures/bigraphs-tutorial.pdf>

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verelo
Its something that we're thinking a lot about at Verelo.com

I've personally been very big on trend graphs myself, how are we doing today
v's yesterday, this week v's last week. I find you learn a lot more from these
than you do any other type of monitoring (unless the issue is dead simple,
like something is down)

We've been focused right now on making great monitoring systems, however we're
just starting to get the chance to step into prevention. Prevention is a fun
area because it starts to include trending.

My hope is that within the next month or two we have a few things. Firstly a
means of providing a great downtime prevention tool, but also an end point
where data can be sent (or we can pull it on your schedule) and then provide a
graph and notifications based on changes in the trending data. Think of it
like stock alerts...

So yep...i agree with you, we need graphing and more of it.

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camtarn
The article isn't about graphs-as-in-charts, but graphs as in the mathematical
concept. In this case, expressing dependencies between different pieces of
operational infrastructure, such that changes to one piece of infrastructure
trigger automatic changes to other pieces.

Unfortunately, the author is pretty vague about exactly what pieces of
infrastructure they imagine defining relationships between, and what triggers
they might use. On the smaller side, they mention 'I changed a config, I must
restart nginx' (micro level dependency between nginx and its config) and
'something changed in my app tier, need to tell my load balancer' (macro-level
dependency between a service and its front-end). What kind of dependencies
would be useful to define between services in a service oriented architecture,
which are usually designed so as to minimize dependencies?

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foogoo1
as stated in a comment on the original blog, work on things like these are
done using rules engines ( based off rete algorithm
<http://en.wikipedia.org/wiki/Rete_algorithm> )

Here is a example of monitoring for a fire in a room, and how one handles it
-- similar concepts can be applied to infrastructure components as well ) --
[http://blog.athico.com/2009/03/drools-quick-start-
stateful-k...](http://blog.athico.com/2009/03/drools-quick-start-stateful-
knowledge.html)

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lusis
Oh wow. I didn't realize until postrank told me that my post had made it to
HN. I'll answer some comments below (and I have another post in the works.

