jjb

For years, people have been using jemalloc with ruby. There are various benchmarks and discussions. Legend had it that Jemalloc 5 doesn't work as well as Jemalloc 3.

Then, one day, hope appeared on the horizon. Someone offered a config for Jemalloc 5.

The recipe would be something like this (shown with official docker ruby image).

FROM ruby:3.1.2-bullseye

natematykiewicz

# A script to migrate Sidekiq's redis to a new server.
# This obviously can work for any redis, but I only handled
# data types that Sidekiq uses.

require 'redis'

old_redis = Redis.new url: 'redis://old-redis:6379'
new_redis = Redis.new url: 'redis://new-redis:6379'

unknowns = []

drnic

# This solution was based on https://gist.github.com/GlenCrawford/16163abab7852c1bd550547f29971c18

Rails.configuration.to_prepare do
  ActiveRecord::SchemaDumper.ignore_tables = %w[
    salesforce._hcmeta
    salesforce._sf_event_log
    salesforce._trigger_log
    salesforce._trigger_log_archive
  ]
end

palkan

Add the following to application.rb:

$icallbacks = []
$icallbacks.define_singleton_method(:print) do
  puts sort_by { |(a, b)| -b }.map { |(a, b)| "#{b}\t\t#{a}" }.join("\n")
end

ActiveSupport::Notifications.subscribe("load_config_initializer.railties") do |event|
 $icallbacks << [event.payload[:initializer], event.duration]

matthewd

#!/usr/bin/env ruby

require(Dir.pwd + "/config/environment")

ActiveRecord::Base.configurations.configs_for(env_name: ActiveRecord::Tasks::DatabaseTasks.env).each do |db_config|
  ActiveRecord::Base.establish_connection(db_config.config)

  context = ActiveRecord::Base.connection.migration_context

  missing_migrations = []

DmitryTsepelev

ActiveRecord::Migration.remove_foreign_key(:current_table, :foreign_table) # no lock

ActiveRecord::Migration.add_column(:current_table, :column_bigint, :bigint) # no lock

copy_data = lambda do
  CurrentTable.where(column_bigint: nil).where.not(column: nil).in_batches do |batch|
    batch.update_all("column_bigint = column")
  end
end

SamSaffron

def recurse(i)
  recurse(i-1) if i > 0
end
threads = ARGV[0].to_i
puts "Running with #{threads} threads!"
threads.times do
  Thread.new do
    recurse(500)
    sleep
    puts "done"

schoblaska

<?xml version="1.0"?>

<!--
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Open "System Preferences > Keyboard > Modifier Keys..." and change caps lock configuration to "No Action"
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<root>

jjb

background

There are many options available for tuning ruby memory management: https://github.com/ruby/ruby/blob/trunk/gc.c#L7420-L7444

The one that gets the most attention is RUBY_GC_HEAP_GROWTH_FACTOR, which is the only one Heroku suggests adjusting: https://devcenter.heroku.com/articles/ruby-memory-use#gc-tuning

I've often wondered what the drawback was for setting RUBY_GC_HEAP_GROWTH_FACTOR quite low for a webapp.

searls

# A little toy file demonstrating how to build chainable
# data transformations that reveal some amount of intent
# through named extracted methods.
#
# Kudos to @mfeathers for giving me the idea to try this
#
# Copyright Test Double, LLC, 2016. All Rights Reserved.

require_relative "marketing_refinements"