Karthik Krishnamurthy kkrs

A Short IPv6 Guide for Home IPv4 Admins

This guide is for homelab admins who understand IPv4s well but find setting up IPv6 hard or annoying because things work differently. In some ways, managing an IPv6 network can be simpler than IPv4, one just needs to learn some new concepts and discard some old ones.

Let’s begin.

First of all, there are some concepts that one must unlearn from ipv4:

Concept 1

PostgreSQL is Enough

Background and Cron Jobs

Uniting the bifunctor and monofunctor hierarchies

With the rise of so-called bifunctor IO types, such as ZIO, questions have naturally arisen of how one could leverage the cats-effect type classes to make use of this new power. So far suggestions have mostly focused on duplicating the existing hierarchy into two distinct branches, one parameterized over F[_] and another parameterized over F[_, _]. To me this is not a great situation, as now library maintainers would have to write code for both of these hierarchies or choose one and leave the other one in the dust.

Instead we should find a way to unite the two shapes under a single hierarchy. This is a draft on how to enable this unification using polymorphic function types in Dotty.

Category Theory and Functional Programming Study Materials

Acronyms/Terms

CT: Category Theory
FP: Functional Programming (typically meaning more pure functional programming)
TFP: Total Functional Programming
TDD: Type Driven Development (e.g. via Idris or Agda)
TT: Type Theory
PLT: Programming Language Theory

Freezer cgroup FTW

In a terminal start a server.

$ python -m SimpleHTTPServer 8000

In another terminal set up the cgroups freezer.

The Elm Architecture is the wrong abstraction for the web

In this article, I'd like to explain why I think The Elm Architecture is fine for small components, but quite harmful for websites based on pages.

Definition and Pros/Cons

First, let's clarify what I mean by "The Elm Architecture".

The Elm Architecture's webpage describes it pretty well.

Overly aggressive CFS

We're looking at CPU bandwidth control via CFS:

https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt

Reproduction program

Program does number of iterations, in each iteration we burn CPU in small chunks until we get 5ms of real time spent. On each iteration we also print how much

	package fpmax

	import scala.util.Try
	import scala.io.StdIn.readLine

	object App0 {
	def main: Unit = {
	println("What is your name?")

	val name = readLine()

	package controllers

	import java.io.File
	import javax.inject.Inject

	import play.api.Logger
	import play.Environment
	import play.api.mvc.{Action, AnyContent}
	import play.mvc.Controller

	default['sshd']['sshd_config']['AuthenticationMethods'] = 'publickey,keyboard-interactive:pam'
	default['sshd']['sshd_config']['ChallengeResponseAuthentication'] = 'yes'
	default['sshd']['sshd_config']['PasswordAuthentication'] = 'no'