Celery 5.x has a known bug: without ack_late, the prefetch count is not enforced correctly. Workers grab all messages from the queue into an internal buffer, acking them immediately on receipt. RabbitMQ then shows 0 "Ready" messages, and autoscalers have nothing to trigger on.
With ack_late enabled, the prefetch limit works correctly: each worker holds at most prefetch_multiplier * concurrency (= 2 in our case) unacked messages, and the rest stay as "Ready" in the queue.
| import logging | |
| log = logging.getLogger('django.db.backends') | |
| log.setLevel(logging.DEBUG) | |
| log.addHandler(logging.StreamHandler()) |
| # frozen_string_literal: true | |
| module Utils | |
| class Timer | |
| def self.call(name) | |
| t = Time.zone.now | |
| result = yield | |
| time = ((Time.zone.now - t).to_d * 1000).to_i | |
| p "++++++++++ #{name}: #{time}ms" | |
| { result: result, time: time } |
| class FooPresenter | |
| include Draper::Decoratable | |
| attr_accessor :user | |
| def initialize(user) | |
| @user = user | |
| end | |
| def name | |
| user.name |
| # Let we have Post(title, body) -> Comments(body). | |
| # Write the active record query to get all posts, where "query" is into title or body or comment. | |
| class Post < ActiveRecord::Base | |
| #title, body | |
| has_many :comments | |
| scope :search, ->(text) { | |
| wildcard_search = "%#{text}%" | |
| joins(:comments).where("title ILIKE :search OR body ILIKE :search OR comments.body ILIKE :search", search: wildcard_search) |
| Dir["app/assets/images/*"].each do |image| | |
| name = File.basename(image) | |
| if Dir.glob("**/*").reject {|fn| File.directory?(fn) }. | |
| map{|fn| File.read(fn).include?(name) ? fn : nil }.any? | |
| p image | |
| else | |
| p "To delete: #{image}" | |
| File.delete image | |
| end | |
| end |
| module AuthenticityTokenCatcher | |
| extend ActiveSupport::Concern | |
| included do | |
| rescue_from ActionController::InvalidAuthenticityToken do |exception| | |
| if request.referrer | |
| flash[:error] = I18n.t :authenticit_token_error | |
| redirect_to request.referrer | |
| else | |
| raise exception | |
| end |
| This is a demo task. | |
| A zero-indexed array A consisting of N integers is given. An equilibrium index of this array is any integer P such that 0 ≤ P < N and the sum of elements of lower indices is equal to the sum of elements of higher indices, i.e. | |
| A[0] + A[1] + ... + A[P−1] = A[P+1] + ... + A[N−2] + A[N−1]. | |
| Sum of zero elements is assumed to be equal to 0. This can happen if P = 0 or if P = N−1. | |
| For example, consider the following array A consisting of N = 8 elements: | |
| A[0] = -1 | |
| A[1] = 3 |
| https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-redis-on-ubuntu-16-04 | |
| How To Install and Configure Redis on Ubuntu 16.04 | |
| PostedMay 11, 2016 51.6k views NOSQL REDIS UBUNTU UBUNTU 16.04 | |
| Introduction | |
| Redis is an in-memory key-value store known for its flexibility, performance, and wide language support. In this guide, we will demonstrate how to install and configure Redis on an Ubuntu 16.04 server. | |
| Prerequisites | |
| To complete this guide, you will need access to an Ubuntu 16.04 server. You will need a non-root user with sudo privileges to perform the administrative functions required for this process. You can learn how to set up an account with these privileges by following our Ubuntu 16.04 initial server setup guide. |
| def flattify(array) | |
| array.each_with_object([]) do |element, flattened| | |
| flattened.push *(element.is_a?(Array) ? flattify(element) : element) | |
| end | |
| end |