Daenyth

import cats.effect.Sync
import io.chrisdavenport.log4cats.Logger
import cats._
import cats.implicits._
import scala.concurrent.duration._

class RetryExample[F[_]](implicit F: Sync[F], log: Logger[F]) {
  case class ApiError(msg: String) extends Exception(msg)
  
  private def getTempFromInternet: EitherT[F, ApiError, Float] = ???

antonfisher

Add --allow-privileged=true to:

# kubelet config
sudo vim /var/snap/microk8s/current/args/kubelet

#kube-apiserver config
sudo vim /var/snap/microk8s/current/args/kube-apiserver

Restart services:

frgomes

import com.typesafe.config.Config
 
implicit class ImplicitConfigHelper(val c: Option[Config]) extends AnyVal {
    import scala.reflect.ClassTag
    import scala.util.control.NonFatal
    import ImplicitConfigHelper._
    implicit def valueOf[T : ClassTag](prop: String)(implicit ev: ClassTag[T]) : T =
      ev.runtimeClass match { // you need stable identifiers here
        case String_ => c.get.getString(prop).asInstanceOf[T]
        case Int_    => c.get.getInt(prop).asInstanceOf[T]

anair-it

Best efforts 1 Phase commit

This is a non-XA pattern that involves a synchronized single-phase commit of a number of resources. Because the 2PC is not used, it can never be as safe as an XA transaction, but is often good enough if the participants are aware of the compromises. The basic idea is to delay the commit of all resources as late as possible in a transaction so that the only thing that can go wrong is an infrastructure failure (not a business-processing error). Systems that rely on Best Efforts 1PC reason that infrastructure failures are rare enough that they can afford to take the risk in return for higher throughput. If business-processing services are also designed to be idempotent, then little can go wrong in practice.

Scenarios

Consider a jms based service, where there is an inbound Queue manager (QM1), an outbound queue manager (QM2) and a database (DB). Here are the scenarios that I would like to cover using Best efforts 1 PC commit process:

Happy path

1. Start MQ transaction on QM1 2

johanandren

import akka.actor.ActorSystem
import akka.stream._
import akka.stream.scaladsl._

import scala.io.StdIn
import scala.util.Random

object SimplePartitionSample extends App {

  implicit val system = ActorSystem()

brunogaspar

Install wkhtmltopdf on Ubuntu

This was tested on:

• Ubuntu 14.04 x64
• Ubuntu 16.04 x64

Installation

tobilg

Custom S3 endpoints with Spark

To be able to use custom endpoints with the latest Spark distribution, one needs to add an external package (hadoop-aws). Then, custum endpoints can be configured according to docs.

Use the hadoop-aws package

bin/spark-shell --packages org.apache.hadoop:hadoop-aws:2.7.2

SparkContext configuration

mnn

mkdir -p ~/.ammonite && wget -O ~/.ammonite/predef.scala --no-check-certificate https://git.io/v6r5y
wget -O amm --no-check-certificate https://git.io/vioDM && chmod u+x amm && ./amm

gigiigig

import shapeless._

import scalaz._
import Scalaz._

object console extends App {

  trait Foo[A] {
    type B
    def value: B

alexandru

import java.security.MessageDigest
import java.util
import javax.crypto.Cipher
import javax.crypto.spec.SecretKeySpec
import org.apache.commons.codec.binary.Base64

/**
 * Sample:
 * {{{
 *   scala> val key = "My very own, very private key here!"