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Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

  1. CPU-bound
  2. Blocking IO
  3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.

@non
non / laws.md
Last active February 20, 2022 00:26
I feel like conversations around laws and lawfulness in Scala are often not productive, due to a lack of rigor involved. I wanted to try to be as clear and specific as possible about my views of lawful (and unlawful) behavior, and what I consider a correct and rigorous way to think about laws (and their limits) in Scala.

Laws

A law is a group of two or more expressions which are required to be the same. The expressions will usually involve one or more typed holes ("inputs") which vary.

Some examples:

x.map(id) === x

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x
@senorcarbone
senorcarbone / ExercisePrimitives.scala
Last active November 14, 2017 04:11
ID2203.1x Exercise Lib
package se.kth.edx.id2203.core
import java.net.{ InetAddress, InetSocketAddress }
import se.kth.edx.id2203.core.ExercisePrimitives.PerfectP2PLink._
import se.kth.edx.id2203.core.Ports._
import se.sics.kompics.{ Init, KompicsEvent }
import se.sics.kompics.network.{ Address, Network, Transport }
import se.sics.kompics.sl.{ ComponentDefinition, _ }
@yang-wei
yang-wei / destructuring.md
Last active December 2, 2024 06:40
Elm Destructuring (or Pattern Matching) cheatsheet

Should be work with 0.18

Destructuring(or pattern matching) is a way used to extract data from a data structure(tuple, list, record) that mirros the construction. Compare to other languages, Elm support much less destructuring but let's see what it got !

Tuple

myTuple = ("A", "B", "C")
myNestedTuple = ("A", "B", "C", ("X", "Y", "Z"))
@vkostyukov
vkostyukov / statuses.md
Last active June 13, 2024 16:30
HTTP status codes used by world-famous APIs
API Status Codes
[Twitter][tw] 200, 304, 400, 401, 403, 404, 406, 410, 420, 422, 429, 500, 502, 503, 504
[Stripe][stripe] 200, 400, 401, 402, 404, 429, 500, 502, 503, 504
[Github][gh] 200, 400, 422, 301, 302, 304, 307, 401, 403
[Pagerduty][pd] 200, 201, 204, 400, 401, 403, 404, 408, 500
[NewRelic Plugins][nr] 200, 400, 403, 404, 405, 413, 500, 502, 503, 503
[Etsy][etsy] 200, 201, 400, 403, 404, 500, 503
[Dropbox][db] 200, 400, 401, 403, 404, 405, 429, 503, 507
@etaty
etaty / JsonCirceBodyParser.scala
Created November 5, 2015 17:30
json circe play framework body parser
package utils
import java.nio.ByteBuffer
import cats.data.Xor
import io.circe.Json
import play.api.http.LazyHttpErrorHandler
import play.api.http.Status._
import play.api.libs.iteratee.{Iteratee, Traversable}
import play.api.mvc.BodyParsers.parse._
@djspiewak
djspiewak / streams-tutorial.md
Created March 22, 2015 19:55
Introduction to scalaz-stream

Introduction to scalaz-stream

Every application ever written can be viewed as some sort of transformation on data. Data can come from different sources, such as a network or a file or user input or the Large Hadron Collider. It can come from many sources all at once to be merged and aggregated in interesting ways, and it can be produced into many different output sinks, such as a network or files or graphical user interfaces. You might produce your output all at once, as a big data dump at the end of the world (right before your program shuts down), or you might produce it more incrementally. Every application fits into this model.

The scalaz-stream project is an attempt to make it easy to construct, test and scale programs that fit within this model (which is to say, everything). It does this by providing an abstraction around a "stream" of data, which is really just this notion of some number of data being sequentially pulled out of some unspecified data source. On top of this abstraction, sca

@noelwelsh
noelwelsh / Example.scala
Created February 20, 2015 16:06
Robust Error Handling in Scala
import scalaz.\/
import scalaz.syntax.either._
object Example2 {
// This example simulates error handling for a simple three tier web application
//
// The tiers are:
// - the HTTP service
// - a user authentication layer
// - a database layer
@tuxfight3r
tuxfight3r / tcp_flags.txt
Last active May 2, 2025 16:54
tcpdump - reading tcp flags
##TCP FLAGS##
Unskilled Attackers Pester Real Security Folks
==============================================
TCPDUMP FLAGS
Unskilled = URG = (Not Displayed in Flag Field, Displayed elsewhere)
Attackers = ACK = (Not Displayed in Flag Field, Displayed elsewhere)
Pester = PSH = [P] (Push Data)
Real = RST = [R] (Reset Connection)
Security = SYN = [S] (Start Connection)