Introducing miniplumber¶

Introduction¶

miniplumber provides uni- and multi-cast experiment communication to VMs, minimega instances, and external programs anywhere in an experiment.

Motivation¶

How do we plumb non-network based connectivity?

• Emulytics helps study many network-centric problems
• minimega builds networks easily
• Great support for describing machine-to-machine structure/behavior
• Not great support for describing machine-to-anything-else structure/behavior

Plumbing the kitchen sink¶

• Buttons
• Serial connections
• Vehicle radars
• physics - sound, heat, light, rabid bunnies
• cyber-physical interactions of all kinds
• measurement data-planes

Plumbing¶

Enter miniplumber

• A networkless, out-of-band, inter-process communication layer
• Quick specification of communication pathways (pipelines)
• uni- or multi-cast experiment communication
• Supports any number of clients (scales along with the rest of minimega)
• Similar to unix pipelines (though not limited to linear pipelines)
• Borrows concepts from the plan 9 plumber
• Newline delimited messages (as opposed to unix byte streams)
• Works on host, in minimega, and any miniccc client (ARM, x86-64 / *bsd, linux, windows)

A quick example¶

# create a pipeline connecting foo and bar
plumb foo "sed -u s/foo/moo/" bar

plumb

# write something to foo
pipe foo "the cow says foo"

shell sleep .5

pipe

# works from the command line too
# echo "hello plumber!" | minimega -pipe foo

clear plumb
clear pipe

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Plumbing objects¶

• Simple standard I/O based communication
• Easily plumbed to existing unix tools
• Several minimega-supplied tools (minevent, distribution functions, etc.)
• Pipelines are plumbed locally, pipe data is forwarded everywhere

# plumbing productions are similar to unix pipelines
plumb "cat data.txt" "grep -i foo" lines_with_foo

# named pipes can attach directly
plumb this is a valid production

# pipelines live until any stage of the pipeline is destroyed
plumb foo "grep -i foo" bar

# kill the above pipeline by closing foo
clear pipe foo

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Plumbing with CC¶

# miniccc programs can attach to pipes directly
# cat data.txt | miniccc -pipe foo
# miniccc -pipe bar | less

# or you can invoke pipes directly
cc exec stdin=foo some_program
cc background stdin=foo stdout=bar some_program

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minimega distribution¶

Fully distributed via meshage

Out-of-band communication¶

• Works over meshage for node-to-node communication
• Uses miniccc/ron for node-to-VM communication
• Fully out-of-band when using miniccc networkless backchannels

Message scheduling¶

• Support for most communication use cases
• one-to-many
• one-to-one (round robin, random)

# create a pipe with round-robin scheduling
pipe foo mode round-robin

pipe

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vias¶

• Produce unique output for every reader on a pipe
• Call an external program N times
• Remote readers also get unique values

# get a normal distributed value for a given mean
pipe foo via bin/normal -stddev 5.0

pipe foo 10.0

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Use cases¶

• cyber-physical experiments
• training
• data forwarding

Summary¶

• miniplumber - simple, out-of-band communication framework
• Growing library of communication primitives, support for any external program
• Bring cyber-physical / simulation layers to emulytics