tef

fair, fine grained, and deadlock free locking

first, a spin lock

you know what a spinlock is, right?

here's a spinlock:

rafaelpontezup

Race conditions, locking e bancos de dados relacionais

Pretendo apresentar um código com uma lógica de negócio simples que funciona bem na perspectiva do negócio mas que quebra miseravelmente em ambientes minimamente concorrentes. Para isso, vou demonstrar através de testes de integração como identificar o Race Condition no código e principalmente como resolvê-lo através de mecanismos de locking e Isolation Level do seu banco de dados;

O que vamos discutir

1. Por que estudamos esse assunto mais a fundo?
   • 1.1. Bootcamp Seniors
   • 1.2. Handora: Curso CRUD e Atualizações Concorrentes com JPA/Hibernate - by Jordi Silva

• 1.3. A importância do treino: o que eu levei alguns bons anos para aprender o Jordi levou 6 meses

rafaelpontezup

import org.slf4j.LoggerFactory
import org.springframework.jdbc.core.JdbcTemplate
import org.springframework.stereotype.Component
import org.springframework.transaction.annotation.Propagation
import org.springframework.transaction.annotation.Transactional
import java.time.Duration

interface LockManager {
    fun <T> tryWithLock(key: Long, timeout: Duration, function: () -> T): T
}

rponte

--
-- Trying to buy a new ticket for an event
--
BEGIN;
    UPDATE events e
       SET updated_at = now()
     WHERE e.id = :event_id
       AND e.max_tickets > (SELECT count(*)           -- (does this logic work with READ_COMMITTED??)
                              FROM tickets t
                             WHERE t.event_id = e.id); 

clemensv

title
Elements of Messaging and Eventing Platforms

This document provides a brief overview of the essential elements of a messaging and eventing platform and how they relate to each other.

Message and Event Broker Categories

missingfaktor

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.

fernandrone

#!/usr/bin/env sh
#
# Simple script that prints out the top N most-used words in a text from standard input.
#
# Inspired by https://buttondown.email/hillelwayne/archive/donald-knuth-was-framed/. The short 
# linux script is first shown at https://www.cs.tufts.edu/~nr/cs257/archive/don-knuth/pearls-2.pdf

topw() {
   tr -cs A-Za-z '\n' | tr A-Z a-z | sort | uniq -c | sort -rn | sed "$N"q
}

stettix

Things I believe

This is a collection of the things I believe about software development. I have worked for years building backend and data processing systems, so read the below within that context.

Agree? Disagree? Feel free to let me know at @JanStette.

Fundamentals

Keep it simple, stupid. You ain't gonna need it.

purcell

-- Let's say you have a table full of work:

CREATE TABLE tasks (
       id UUID PRIMARY KEY NOT NULL DEFAULT gen_random_uuid(),
       status TEXT NOT NULL DEFAULT 'pending',
       payload JSON NOT NULL, -- or just have meaningful columns!
       created_at TIMESTAMP NOT NULL DEFAULT NOW()
);

TimothyJones

#!/bin/bash -eu
if [ -z "${LIB_ROBUST_BASH_SH:-}" ]; then
  LIB_ROBUST_BASH_SH=included

  function error {
    echo "Error:  ${1:-}"
  }

  # Check to see that we have a required binary on the path
  function require_binary {