alazycoder101

Debug Ruby

Installation

# install ruby with debug options with asdf
RUBY_CFLAGS=-O0 CONFIGURE_OPTS='cppflags=-DUSE_RUBY_DEBUG_LOG=1 --enable-debug-env optflags=-fno-omit-frame-pointer' asdf install ruby 3.3.2

output

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Title: Mastering Redis Memory Management with Microserver and Sidekiq

Introduction: Microservers have become increasingly popular due to their flexibility and ease of deployment and testing. However, they also present challenges, particularly with memory management in services like Redis. In this article, we'll explore a real-world scenario where Redis memory usage spiked dramatically and the steps taken to regain control.

The Challenge: Redis Memory Surge Recently, I encountered a significant increase in Redis memory usage, jumping from 130MB to 800MB. Initially, I suspected the Redis cache was the culprit.

Redis Memory Inspection Upon inspection with the INFO memory command, the memory usage was as follows:

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GIL/GVL

What is the Global VM Lock (GVL)?

• Also known as the Global Interpreter Lock (GIL)
• A mutex that prevents multiple native threads from executing Ruby code in parallel
• Present in CRuby (the reference implementation of Ruby)

Purpose of the GVL

• Protects internal data structures from race conditions
• Ensures thread safety in the Ruby interpreter

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Advanced Debugging Techniques for Production Issues

Introduction

In an ideal world, developers would be able to replicate all production problems locally, debug them, and roll out patches with the next release. However, real-life scenarios are often far more complex. Production environments present unique challenges that are difficult to replicate in development or even staging environments. This article explores various techniques for troubleshooting production issues, ranging from pre-production strategies to advanced debugging in live environments.

Challenges of Production Debugging

Several factors make production debugging particularly challenging:

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IRB.conf[:PROMPT][:DEV] = { # name of prompt mode
  :AUTO_INDENT => false,          # disables auto-indent mode
  :PROMPT_I =>  ">> ",            # simple prompt
  :PROMPT_S => nil,               # prompt for continuated strings
  :PROMPT_C => nil,               # prompt for continuated statement
  :RETURN => "    ==>%s\n"        # format to return value
}

#IRB.conf[:PROMPT_MODE] = :MY_PROMPT

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joins, preload, eager_load, and includes

joins

Use this when you only care about the users with questions

> User.joins(:questions).to_a;0
  User Load (0.8ms)  SELECT "users".* FROM "users" INNER JOIN "questions" ON "questions"."user_id" = "users"."id"

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def check_queue(queues=[])
  if queues.empty?
    
    queues = Sidekiq::Queue.all
  else
    queues = queues.map { |queue| Sidekiq::Queue.new(queue) }
  end
  queues.each do |queue|
    queue.each do |job|

alazycoder101

require 'net/http'
module Net
  class HTTP
    def self.enable_debug!
      class << self
        alias_method :__new__, :new
        def new(*args, &blk)
          instance = __new__(*args, &blk)
          instance.set_debug_output($stderr)
          instance

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check process

ps -ef|grep sidekiq

tail -f /proc/<pid>/fd/1
1 = stdout, 2 = stderr

check queues

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const { IncomingWebhook } = require('@slack/webhook');
const url = process.env.SLACK_WEBHOOK_URL;

const webhook = new IncomingWebhook(url);

// Optionally filter what notification types to forward to Slack.
// If empty, all types will be allowed.
const allowedTypeURLs = [];

// slackNotifier is the main function called by Cloud Functions