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A comment on Billions wasted on Hadoop startups, the same will eventually be true of Docker. Parent comment

Re:Billions wasted on Hadoop startups, the same will eventua... by hardwaresofton on Friday May 31, 2019 @09:44AM (#20060765)
This is precisely why I said the fact that someone would gloss over this is a red flag. The point is super critical.

VMs are literally so hard to do correctly and in a performant fashion that parts of CPU instruction sets[0], and kernel subsystems (KVM[1]) were created to make them easier to run. Containers, in contrast are literally a few flags and a bunch of in-kernel antics.

A few people, notably Liz Rice and Jessie Frazelle have given talks on how to make containers from scratch that are very illuminating for those that are interested:

https://www.youtube.com/watch?v=HPuvDm8IC-4

https://www.youtube.com/watch?v=cYsVvV1aVss

[0]: https://en.wikipedia.org/wiki/X86_virtualization

[1]: https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine

[ Parent | on HN ]
Re:Billions wasted on Hadoop startups, the same will eventua... by panpanna on Friday May 31, 2019 @10:32AM (#20061228)
Containers are "easy" because they are backed by tons of kennel code (cgroups, namespaces and basically a small part of many other subsystems). You can actually create containers from the shell!

VMs are "hard" because you start with nothing save some very low-level help from the hardware.

[ Parent | on HN ]
Re:Billions wasted on Hadoop startups, the same will eventua... by hardwaresofton on Friday May 31, 2019 @10:50AM (#20061400)
Also, I want to be clear that I'm using "simple" and "easy" in the rick hickey sense of the words, as in "simple" has more to do with what a thing is made of, and "easy" has more to do with ease of use, taking available tooling/familiarity and context into mind.

What I should have made clearer was that I think containers are both easier and simpler than VMs. There are both less moving parts (I haven't looked, but I assume less code), and containers are easier to get started with than VMs (set some flags on some syscalls versus make sure you buy the right CPU).

[ Parent | on HN ]
Re:Billions wasted on Hadoop startups, the same will eventua... by panpanna on Friday May 31, 2019 @11:04AM (#20061534)
Fair enough, but don't forget there are some extremely simple hypervisor implementations out there too.
[ Parent | on HN ]