Speaker Notes for my presentation at Atlanta Riak meetup: Slides - https://speakerdeck.com/lusis/why-riak-matters

why-riak-matters-notes.md

Disclaimers and Disclosures

• Basho fanboy
• Basho customer
• enStratius product uses Riak
• thus all customers run Riak as part of install
• I am far from a subject matter expert

What this is not about

• Running Riak in production
• Riak itself
• Riak administration or tuning

What even is a "distributed system"?

• Basic definition - "A distributed system consists of multiple computers that communicate through a computer network."
• Jeff Hodges blog post - http://www.somethingsimilar.com/2013/01/14/notes-on-distributed-systems-for-young-bloods/
• which links to "The fallacies" - http://en.wikipedia.org/wiki/Fallacies_of_Distributed_Computing
• Read stuff by Kyle Kingsbury on the topic
• Read Boundary blog posts (I'll say this a lot)
• Single system problems are trivial but even single systems you have properties of distributed systems
• It's not just your systems at play. External APIs. Browsers.

Fallacies of Distributed Computing

• The network is reliable. (partition tolerance)
• Latency is zero. (eventual consistency)
• Bandwidth is infinite. (max node count)
• The network is secure. (riak provides SSL)
• Topology doesn't change.
• There is one administrator.
• Transport cost is zero.
• The network is homogeneous

logo

• quick note about the logo
• cribbed from Justin Sheehey's Velocity talk
• Each dot contains the same diagram
• a distributed system within your distributed system

Riak is honest about its limitations

• and embraces them
• read the mailing list
• read basho blog posts

Riak forces you to think about your data model

• Do you really need a relational model? 5th normal form? Really?
• What is your native format anyway?
• Can you loosen your consistency requirements?

Riak is about tradeoffs

• Querying is a pain in the ass (Riak+Redis)
• Read any Boundary blog post
• Read any mailing list post
• Riak let's you choose (tunable CAP, multiple backends)
• Riak doesn't try to be something it isn't

Riak is in Erlang (wat)

• Erlang isn't perfect. There are shitty Erlang apps.
• Alan Kay/Smalltalk/Message Passing
• Actor Pattern
• Let It Crash
• Basho contributes back to the Erlang ecosystem to make it more approachable (rebar, lager, webmachine)

What can we learn?

• Revisit the fallacies
• Revisit CAP
• Embrace failure
• Fault Tolerance vs. Fault Prevention
• Your entire stack doesn't have the same requirements (strict consistency vs. weak consistency)
• Easy to reason about. (which is easier - let it crash or some complicated recovery scenario?)
• Network partitions happen.
• Be careful with clever
• Each additional component risks unnecessary additional complexity and reduces reasonability