notes

20210323005824-distributed_systems.org

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+#+title: Distributed Systems
+
+A [[file:20210310182044-software_architecture.org][Software Architecture]] consisting of multiple independant pieces of software
+coordinating via message passing.
+
+* [[file:20210323010700-process_isolation.org][Process Isolation]]
+- Monolith vs. Services
+* [[file:20210323012431-concurrent_and_parallel_programming.org][Concurrent and Parallel Programming]]
+
+#+begin_quote
+A system is said to be concurrent if it can support two or more actions in
+progress at the same time. A system is said to be parallel if it can support two
+or more actions executing simultaneously.
+
+-- Clay Breshears, The Art Of Concurrency
+#+end_quote
+
+- Parallel :: Occurring at the same time
+- Concurrent :: Occuring independently
+
+Python threads are concurrent, but not parallel (execution is serialized,
+contending for access to the Global Interpreter Lock).
+* [[file:20210323010014-cap_theorem.org][CAP Theorem]]
+* [[file:20210323010307-conflict_free_replicated_data_types.org][CRDTs]]

20210323010014-cap_theorem.org

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+#+title: CAP Theorem
+
+States that a [[file:20210323005824-distributed_systems.org][Distributed System]] cannot simultaneously be consistent, available,
+and partition tolerant -- typically only achieving two of the three.
+
+* Consistency
+* Availability
+* Partition Tolerance

20210323010307-conflict_free_replicated_data_types.org

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+#+title: Conflict-Free Replicated Data Types
+#+ROAM_ALIAS: CRDTs
+
+Alternatively, Commutative Replicated Data Types.

20210323010700-process_isolation.org

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+#+title: Process Isolation
+
+Making a process wholly independent, preventing any access of its internal state
+by any other process and communicating by sending and recieving messages.

20210323011000-the_actor_model.org

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+#+title: The Actor Model
+
+A design in [[file:20210310182044-software_architecture.org][Software Architecture]] in which [[file:20210323010700-process_isolation.org][Isolated Processes]] work together as a
+[[file:20210323005824-distributed_systems.org][Distributed System]], coordinating via message passing. This is modeled similarly
+to how interactions occur in nature.
+
+This is remarkably similar to Alan Kay's initial concept of [[file:20210323011337-object_oriented_programming.org][Object-Oriented
+Programming]].

20210323011337-object_oriented_programming.org

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+#+title: Object-Oriented Programming

20210323012431-concurrent_and_parallel_programming.org

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+#+title: Concurrent and Parallel Programming
+#+roam_key: https://joearms.github.io/published/2013-04-05-concurrent-and-parallel-programming.html
+#+roam_tags: literature articles
+
+From Joe Armstrong's blog:
+
+#+begin_quote
+What's the difference between concurrency and parallelism?
+
+Explain it to a five year old.
+
+[[file:data/fb/2246e7-e0a7-455b-a030-1bd4dfda4ce3/con_and_par.jpeg]]
+
+- Concurrent :: Two queues and one coffee machine.
+- Parallel :: Two queues and two coffee machines.
+#+end_quote
+
+* Attachments :ATTACH:noexport:
+:PROPERTIES:
+:ID:       fb2246e7-e0a7-455b-a030-1bd4dfda4ce3
+:END: