The Network as a Language Construct

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ESOP 2014, Grenoble, France; 20140410

The Network as a Language Construct

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Actor Programming Languages

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? ? ?

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Routing

Events

Hierarchical

Layering

Publish/Subscribe for Actors

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This Talk

Routing

Events

Hierarchical

Layering

Publish/Subscribe for Actors

Erlang/OTP, Scala/Akka, ...

See Paper

Network

Calculus

Actor

Calculus

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Functional I/O

Scaling up big-bang from domain-speciﬁc to general functional I/O

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Functional I/O

Apps in a functional I/O style:

• echo server

• multi-user chat • DNS server

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Functional I/O

Distributed Systems

Implementing RabbitMQ

and using it to build distributed systems

• echo server

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Functional I/O

Distributed Systems

Implementing RabbitMQ

and using it to build distributed systems

• echo server

• SSH server

Investigated other paradigms:

• OO languages

• Network architecture • CORBA services

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Ubiquitous Patterns and Problems

Event broadcasting

Naming service

Service discovery

Startup ordering

Crash/exit signalling

Conversation management

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Ubiquitous Patterns and Problems

Event broadcasting

Naming service

Service discovery

Startup ordering

Crash/exit signalling

Conversation management

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Recipe for Actor Languages

Base language actor

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Logging: Requirements Scorecard

Route log entries from producers to consumers Consumers ﬁlter log messages Decouple producers from consumers Avoid shared-state explosion Discovery of logging service Only produce if someone's listening Alert when a producer crashes/exits Uniform treatment of I/O

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Route log entries from producers to consumers

✔

"Router" actor Consumers ﬁlter log messages

✔

"Router" actor Decouple producers from consumers

✔

"Router" actor Avoid shared-state explosion

✔

"Router" actor

Discovery of logging service Only produce if someone's listening Alert when a producer crashes/exits Uniform treatment of I/O

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Route by address

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Route by address

Route by content

Messages

Patterns Interests

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Route by address

Route by content

or or or

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✔

pub/sub Consumers ﬁlter log messages

✔

pub/sub Decouple producers from consumers

✔

pub/sub Avoid shared-state explosion

✔

pub/sub Discovery of logging service no need! Only produce if someone's listening

Alert when a producer crashes/exits

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✔

Consumers ﬁlter log messages

✔

Decouple producers from consumers

✔

Avoid shared-state explosion

✔

Discovery of logging service Only produce if someone's listening Alert when a producer crashes/exits

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Shared Conversational Interest

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What is a Routing Event?

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causes

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Routing Events for Crash Detection

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!

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!

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Routing Events for Crash Detection

!

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!

pager

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✔

pub/sub

Discovery of logging service

✔

routing events Only produce if someone's listening

✔

routing events Alert when a producer crashes/exits

✔

routing events

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✔

pub/sub

✔

routing events

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✔

Consumers ﬁlter log messages

✔

Decouple producers from consumers

✔

Avoid shared-state explosion

✔

Only produce if someone's listening

✔

Alert when a producer crashes/exits

✔

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Layers make I/O Uniform

Logging

pager magic!

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Layers make I/O Uniform

Logging pager magic! ordinary actions Logging pager Pager communication

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Layers make I/O Uniform

Logging pager magic! ordinary actions Logging pager Pager communication

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Layers Compose

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Layers Compose

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Layers Compose

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One Layer = One Protocol

...

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... ... ... ... TCP header Encrypted payload SSH command App message

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...

UDP header DNS header

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Snoops via pub/sub to populate cache!

...

UDP header DNS header

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Logging: Requirements Scorecard

✔

pub/sub

✔

routing events

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✔

pub/sub

✔

routing events

Uniform treatment of I/O

✔

layering + great additional beneﬁts from layering

✔

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Marketplace

Minimart

JS-Marketplace

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Marketplace

Minimart

JS-Marketplace

Typed Racket Racket Javascript DNS server (UDP) SSH server (TCP) Chat server Echo server Websocket driver Generic msg broker Websocket driver DOM driver jQuery driver Chat + roster GUI composition

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Marketplace

Minimart

JS-Marketplace

Typed Racket Racket Javascript DNS server (UDP) SSH server (TCP) Chat server Echo server Websocket driver Generic msg broker Websocket driver DOM driver jQuery driver Chat + roster GUI composition Details and experience report in the paper!

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Actor Programming Language

+ Publish/Subscribe

+ Routing Events

+ Hierarchical Layering

Network Calculus Actor Calculus (see paper) Experience reports (see paper)

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Actor Programming Language

+ Publish/Subscribe

+ Routing Events

+ Hierarchical Layering

Thank you!

Network Calculus Actor Calculus (see paper) Experience reports (see paper) http://www.ccs.neu.edu/home/tonyg/marketplace/