Eventually Consistent: How to Make a Mobile-First Distributed System

Re:Eventually Consistent: How to Make a Mobile-First Distrib... by bitwiseand on Thursday January 19, 2017 @03:33PM (#13439225)

I liked the article but I feel the CAP theorem is again misquoted; it often leads to misunderstanding. From the article - "but they would still confront the reality of the CAP theorem: your system can be consistent, available, or partition-tolerant, and you can only pick two"

The CAP theorem states that in the event of a network-partition you have to choose one of C or A. More intuitively, any delay between nodes can be modeled as a temporary network partition and in that event you have but two choices either wait to return the latest data at a peer node (C) or return the last available data at a peer node (A).

Edit: Switched C and A

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by bigfish24 on Thursday January 19, 2017 @04:10PM (#13439524)

Agree that the CAP theorem isn't as strict as that statement implies. The trade-off only occurs at certain points. Sorry it was a little unclear!

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by bitwiseand on Thursday January 19, 2017 @05:11PM (#13439921)

No need to be sorry. I liked the rest of the article. Thanks for that.

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by bitwiseand on Thursday January 19, 2017 @05:13PM (#13439939)

Edit: I also wrote my comment because the article is beginner friendly. A lot of beginners will get the right idea about CAP once they go through comments and then back again to your article.

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by bandwitch on Thursday January 19, 2017 @04:09PM (#13439514)

Couldn't agree more. This kind of misunderstanding is also described in Brewer's paper "CAP twelve years later: How the "rules" have changed" (http://ieeexplore.ieee.org/document/6133253/).

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by _dark_matter_ on Thursday January 19, 2017 @05:49PM (#13440200)

This is a fantastic article that every engineer who touches a distributed system should read. The simplistic CAP understanding hurts systems by forcing the choice before it needs to be made; i.e. we can (sometimes) have our cake and eat it too.

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by devty on Thursday January 19, 2017 @04:23PM (#13439619)

Good point. I often heard that it makes no sense to NOT deal with network partitions and CAP as an "illusion of choice"[1]

[1] http://bravenewgeek.com/cap-and-the-illusion-of-choice/

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by toomim on Friday January 20, 2017 @05:38AM (#13442807)

What a wonderful explanation! You've cleared up hours of confusion I've experienced in my life, with just 2 sentences!

I'm motherf*ing amazzzzzed!!!!!!!

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Re:Eventually Consistent: How to Make a Mobile-First Distrib... by bitwiseand on Friday January 20, 2017 @06:42PM (#13447860)

Thanks :)

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