rponte

async def create_charge(charge: Charge, customer: Customer) -> None:
	
    if not customer.is_active():
        raise Customer InactiveError("The customer is not active.")
		
    if not charge.has_valid_amount():
        raise InvalidChargeAmountError("The charge amount must be greater than zero.")
		
    if not charge.has_valid_due_date():
        raise InvalidDueDateError("The due date must be in the future.")

rponte

import org.assertj.core.groups.Tuple;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.ActiveProfiles;

import jakarta.validation.ConstraintViolation;
import jakarta.validation.Validator;

rponte

fair, fine grained, and deadlock free locking

first, a spin lock

you know what a spinlock is, right?

here's a spinlock:

rponte

# Brilliant one-liner

(echo "PID COMMAND PORT USER"; lsof -i -P -n | grep LISTEN | awk '{print $2, $1, $9, $3}' | sort -u | head -n 50; echo;) \
 | column -t \
 | llm "what servers are running on my machine and do some of them look like they could be orphaned things I can shut down"
 
 
 # Maybe even more brilliant one liner
 
 (echo "PID COMMAND PORT USER"; lsof -i -P -n | grep LISTEN | awk '{print $2, $1, $9, $3}' | sort -u | head -n 50) \

rponte

package base;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

rponte

package br.com.rponte.sample.ssh;

import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.file.Path;

rponte

-- (This code was run in PostgreSQL 9.6.1)
-- Demonstration of how serializable isolation for PostgreSQL, which detects possible
-- interference between concurrent transactions, can produce false positives

-- in psql, create the following table

CREATE TABLE users(
  id SERIAL NOT NULL PRIMARY KEY,
  username VARCHAR NOT NULL
);

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Interesting articles and content about data partitioning

Slotted Counter Pattern

Some articles and tips about Slotted Counter Pattern:

• PostgreSQL Lock Contention For Frequently Updated Rows
  • Example of how partitioning a counter can improve throughput without giving up locks
• PlanetScale: The Slotted Counter Pattern
• Hacker News: The Slotted Counter Pattern

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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

rponte

Create Repository Gitlab

Creates a new repository (aka project) in a specific Gitlab group.

How to set up this project

This project was developed with Python v3.9, and it also uses Python's Virtualenv tool. So before working on this project we need to set up it.

Inside this project's folder, execute those commands to configure your environment: