kellabyte

// CQS (Command-Query Separation)
// Bertrand Meyer devised the CQS principle
// It states that every method should either be a command that performs an action, or a 
// query that returns data to the caller, but not both. In other words, asking a question 
// should not change the answer. More formally, methods should return a value only if they 
// are referentially transparent and hence possess no side effects.
//
// Example: 

public class CustomerService

groovybayo

Step by step guide to setting up IDEA to write gatling simulations

Prerequisites:

Have [SBT plugin][sbt-plugin] installed

Begin

• [Create a new project][create-project] in IDEA ( File > New Project ...)
  • Make sure you select a maven module

dodyg

#Intro

Kotlin is a new programming language for the JVM. It produces Java bytecode, supports Android and generates JavaScript. The latest version of the language is Kotlin M5.3

Kotlin project website is at kotlin.jetbrains.org.

All the codes here can be copied and run on Kotlin online editor.

Let's get started.

fjavieralba

import java.io.IOException;
import java.util.Properties;
import kafka.server.KafkaConfig;
import kafka.server.KafkaServerStartable;
 
 
public class KafkaLocal {
 
	public KafkaServerStartable kafka;
	public ZooKeeperLocal zookeeper;

kchida

- What do Etcd, Consul, and Zookeeper do?
  - Service Registration:
    - Host, port number, and sometimes authentication credentials, protocols, versions
      numbers, and/or environment details.
  - Service Discovery:
    - Ability for client application to query the central registry to learn of service location.
  - Consistent and durable general-purpose K/V store across distributed system.
    - Some solutions support this better than others.
    - Based on Paxos or some derivative (i.e. Raft) algorithm to quickly converge to a consistent state.
    - Centralized locking can be based on this K/V store.

hamnis

public static <A, B> B foldLeft(Stream<A> iterable, B identity, BiFunction<B, A, B> bf) {
    return foldLeft(iterable.iterator(), identity, bf);
}

public static <A, B> B foldLeft(Iterable<A> iterable, B identity, BiFunction<B, A, B> bf) {
    return foldLeft(iterable.iterator(), identity, bf);
}

public static <A, B> B foldLeft(Iterator<A> iterator, B identity, BiFunction<B, A, B> bf) {
    B result = identity;

mvniekerk

import io.vertx.core.Vertx
import io.vertx.ext.web.Router
import za.co.koperfontein.amapogo.safetyq.mongo.MONGO_ENTRY_PAGE_ENABLE_DISABLE
import za.co.koperfontein.amapogo.safetyq.mongo.MONGO_ENTRY_PAGE_GET
import za.co.koperfontein.amapogo.safetyq.mongo.MONGO_ENTRY_PAGE_VALUES_UPDATE

// Example usage
class PageHttpRoutes(router: Router, vertx: Vertx): RegisterHttpRoutes(router, vertx) {
    override fun registerRoutes() {

jdegoes

object test {
  import scalaz.zio._

  type UserID = String
  case class UserProfile(name: String)

  // The database module:
  trait Database {
    val database: Database.Service

colomboe

// Porting of https://gist.github.com/jdegoes/dd66656382247dc5b7228fb0f2cb97c8

typealias UserID = String
data class UserProfile(val name: String)

// The database module:
interface DatabaseService {
    suspend fun dbLookup(id: UserID): UserProfile
    suspend fun dbUpdate(id: UserID, profile: UserProfile)
}

MichaelDrogalis

I've been working with Apache Kafka for over 7 years. I inevitably find myself doing the same set of activities while I'm developing or working with someone else's system. Here's a set of Kafka productivity hacks for doing a few things way faster than you're probably doing them now. 🔥

• Show me all my Kafka topics and their partitions, replicas, and consumers
• Show me the contents of a topic
• Create a Kafka topic
• Produce messages to a Kafka topic
• Validate the schema of messages before producing to a topic
• Do all of this at a distance

Get the tools