通过使用Redis，我尝试在Ruby on Rails上创建排名系统。
我的环境：Windows10，无业游民，Ruby -v 2.2.3，rails -v 4.2.5，mysql2 -v 0.3.18 ...
但是我遇到以下错误。
在127.0.0.1:6379（ECONNREFUSED）上连接到Redis的错误
this is error pic on rails application...
我想不是出在app / posts_controller.rb中的代码而是我的其他设置文件出了点问题。
这就是为什么当我在zadd hoge 1 1上使用zrange hoge 0 -1在tarminal上运行redis-cli和redis-server等时，我的输出毫无问题。
与我的rails应用程序相关的以下文件：
gemfile.lock
首先，我运行捆绑安装gem 'redis'和gem 'redis-rails'。
GEM
remote: https://rubygems.org/
specs:
actionmailer (4.2.5)
actionpack (= 4.2.5)
actionview (= 4.2.5)
activejob (= 4.2.5)
mail (~> 2.5, >= 2.5.4)
rails-dom-testing (~> 1.0, >= 1.0.5)
actionpack (4.2.5)
actionview (= 4.2.5)
activesupport (= 4.2.5)
rack (~> 1.6)
rack-test (~> 0.6.2)
rails-dom-testing (~> 1.0, >= 1.0.5)
rails-html-sanitizer (~> 1.0, >= 1.0.2)
actionview (4.2.5)
activesupport (= 4.2.5)
builder (~> 3.1)
erubis (~> 2.7.0)
rails-dom-testing (~> 1.0, >= 1.0.5)
rails-html-sanitizer (~> 1.0, >= 1.0.2)
activejob (4.2.5)
activesupport (= 4.2.5)
globalid (>= 0.3.0)
activemodel (4.2.5)
activesupport (= 4.2.5)
builder (~> 3.1)
activerecord (4.2.5)
activemodel (= 4.2.5)
activesupport (= 4.2.5)
arel (~> 6.0)
activesupport (4.2.5)
i18n (~> 0.7)
json (~> 1.7, >= 1.7.7)
minitest (~> 5.1)
thread_safe (~> 0.3, >= 0.3.4)
tzinfo (~> 1.1)
arel (6.0.4)
bcrypt (3.1.12)
binding_of_caller (0.8.0)
debug_inspector (>= 0.0.1)
builder (3.2.3)
byebug (10.0.2)
coderay (1.1.2)
coffee-rails (4.1.1)
coffee-script (>= 2.2.0)
railties (>= 4.0.0, < 5.1.x)
coffee-script (2.4.1)
coffee-script-source
execjs
coffee-script-source (1.12.2)
concurrent-ruby (1.0.5)
crass (1.0.4)
debug_inspector (0.0.3)
devise (4.5.0)
bcrypt (~> 3.0)
orm_adapter (~> 0.1)
railties (>= 4.1.0, < 6.0)
responders
warden (~> 1.2.3)
erubis (2.7.0)
execjs (2.7.0)
globalid (0.4.1)
activesupport (>= 4.2.0)
hike (1.2.3)
i18n (0.9.5)
concurrent-ruby (~> 1.0)
jbuilder (2.7.0)
activesupport (>= 4.2.0)
multi_json (>= 1.2)
jquery-rails (4.3.3)
rails-dom-testing (>= 1, < 3)
railties (>= 4.2.0)
thor (>= 0.14, < 2.0)
json (1.8.6)
loofah (2.2.2)
crass (~> 1.0.2)
nokogiri (>= 1.5.9)
mail (2.7.0)
mini_mime (>= 0.1.1)
method_source (0.9.0)
mini_mime (1.0.1)
mini_portile2 (2.3.0)
minitest (5.11.3)
multi_json (1.13.1)
mysql2 (0.3.18)
nokogiri (1.8.4)
mini_portile2 (~> 2.3.0)
orm_adapter (0.5.0)
pry (0.11.3)
coderay (~> 1.1.0)
method_source (~> 0.9.0)
pry-rails (0.3.6)
pry (>= 0.10.4)
rack (1.6.10)
rack-test (0.6.3)
rack (>= 1.0)
rails (4.2.5)
actionmailer (= 4.2.5)
actionpack (= 4.2.5)
actionview (= 4.2.5)
activejob (= 4.2.5)
activemodel (= 4.2.5)
activerecord (= 4.2.5)
activesupport (= 4.2.5)
bundler (>= 1.3.0, < 2.0)
railties (= 4.2.5)
sprockets-rails
rails-deprecated_sanitizer (1.0.3)
activesupport (>= 4.2.0.alpha)
rails-dom-testing (1.0.9)
activesupport (>= 4.2.0, < 5.0)
nokogiri (~> 1.6)
rails-deprecated_sanitizer (>= 1.0.1)
rails-html-sanitizer (1.0.4)
loofah (~> 2.2, >= 2.2.2)
railties (4.2.5)
actionpack (= 4.2.5)
activesupport (= 4.2.5)
rake (>= 0.8.7)
thor (>= 0.18.1, < 2.0)
rake (12.3.1)
rdoc (4.3.0)
redis (3.2.0)
redis-actionpack (5.0.2)
actionpack (>= 4.0, < 6)
redis-rack (>= 1, < 3)
redis-store (>= 1.1.0, < 2)
redis-activesupport (5.0.7)
activesupport (>= 3, < 6)
redis-store (>= 1.3, < 2)
redis-rack (2.0.4)
rack (>= 1.5, < 3)
redis-store (>= 1.2, < 2)
redis-rails (5.0.2)
redis-actionpack (>= 5.0, < 6)
redis-activesupport (>= 5.0, < 6)
redis-store (>= 1.2, < 2)
redis-store (1.5.0)
redis (>= 2.2, < 5)
responders (2.4.0)
actionpack (>= 4.2.0, < 5.3)
railties (>= 4.2.0, < 5.3)
sass (3.2.19)
sass-rails (4.0.5)
railties (>= 4.0.0, < 5.0)
sass (~> 3.2.2)
sprockets (~> 2.8, < 3.0)
sprockets-rails (~> 2.0)
sdoc (0.4.2)
json (~> 1.7, >= 1.7.7)
rdoc (~> 4.0)
spring (2.0.2)
activesupport (>= 4.2)
sprockets (2.11.0)
hike (~> 1.2)
multi_json (~> 1.0)
rack (~> 1.0)
tilt (~> 1.1, != 1.3.0)
sprockets-rails (2.3.3)
actionpack (>= 3.0)
activesupport (>= 3.0)
sprockets (>= 2.8, < 4.0)
thor (0.20.0)
thread_safe (0.3.6)
tilt (1.4.1)
turbolinks (5.2.0)
turbolinks-source (~> 5.2)
turbolinks-source (5.2.0)
tzinfo (1.2.5)
thread_safe (~> 0.1)
uglifier (4.1.19)
execjs (>= 0.3.0, < 3)
warden (1.2.7)
rack (>= 1.0)
web-console (2.3.0)
activemodel (>= 4.0)
binding_of_caller (>= 0.7.2)
railties (>= 4.0)
sprockets-rails (>= 2.0, < 4.0)
PLATFORMS
ruby
DEPENDENCIES
byebug
coffee-rails (~> 4.1.0)
devise
jbuilder (~> 2.0)
jquery-rails
mysql2 (= 0.3.18)
pry-rails
rails (= 4.2.5)
redis (= 3.2.0)
redis-rails
sass-rails (~> 4.0.2)
sdoc (~> 0.4.0)
spring
sprockets (= 2.11.0)
turbolinks
uglifier (>= 1.3.0)
web-console (~> 2.0)
BUNDLED WITH
1.10.6
配置/初始化/redis.rb
第二，我创建了这个文件。
require 'redis'
uri = URI.parse(ENV["REDIS"])
REDIS = Redis.new(host: uri.host, port: uri.port)
config / environments / development.rb
第三，我在最下面的行中添加了ENV["REDIS"] = "localhost:6379"。
Rails.application.configure do
# Settings specified here will take precedence over those in config/application.rb.
# In the development environment your application's code is reloaded on
# every request. This slows down response time but is perfect for development
# since you don't have to restart the web server when you make code changes.
config.cache_classes = false
# Do not eager load code on boot.
config.eager_load = false
# Show full error reports and disable caching.
config.consider_all_requests_local = true
config.action_controller.perform_caching = false
# Don't care if the mailer can't send.
config.action_mailer.raise_delivery_errors = false
# Print deprecation notices to the Rails logger.
config.active_support.deprecation = :log
# Raise an error on page load if there are pending migrations.
config.active_record.migration_error = :page_load
# Debug mode disables concatenation and preprocessing of assets.
# This option may cause significant delays in view rendering with a large
# number of complex assets.
config.assets.debug = true
# Asset digests allow you to set far-future HTTP expiration dates on all assets,
# yet still be able to expire them through the digest params.
config.assets.digest = true
# Adds additional error checking when serving assets at runtime.
# Checks for improperly declared sprockets dependencies.
# Raises helpful error messages.
config.assets.raise_runtime_errors = true
# Raises error for missing translations
# config.action_view.raise_on_missing_translations = true
ENV["REDIS"] = "localhost:6379"
end
app / controller / posts_controller.rb
最后，我在 def索引和 def show 中描述了新代码。
ids = REDIS.zrevrange“ ranking”，0，-1 @ranking_posts = Post.where（id：ids）
REDIS.zincr通过“排名”，1，“＃{@ post.id}”
顺便说一句，如果我没有描述上面的两个描述， 当然，我的rails应用程序可以工作。
class PostsController < ApplicationController
def index
@posts = Post.all.order(id: :desc)
ids = REDIS.zrevrange "ranking", 0, -1
#the order of posts ranking
@ranking_posts = Post.where(id: ids)
end
def show
@post = Post.find_by(id: params[:id])
# update ranking
REDIS.zincrby "ranking", 1, "#{@post.id}"
end
def new
end
def create
Post.create(name: post_params[:name], text: post_params[:text], user_id: current_user.id)
redirect_to("/")
end
def destroy
post = Post.find(params[:id])
if post.user_id == current_user.id
post.destroy
end
redirect_to("/")
请告诉我如何解决此错误...（； ^；）
答案 0 :(得分：1)
Rails不会启动Redis服务器。您在此处提供的配置仅设置redis客户端以与redis服务器通信。您必须安装并启动redis才能使其连接。
https://redislabs.com/ebook/appendix-a/a-3-installing-on-windows/a-3-2-installing-redis-on-window/
答案 1 :(得分：1)
根据文章中提到的描述，您可以在运行redis-server之后在终端上运行redis命令。
这就是为什么当我运行zadd hoge 1 1和zrange hoge 0 -1等时 通过在使用redis-server后使用redis-cli进行tarminal，我得到了结果 没问题。
但是在运行Rails应用程序时，似乎您的Redis服务器未运行，这就是为什么在连接到localhost：6379时说错误
尝试在与Rails服务器并行的新选项卡中运行下面提到的命令
redis-server
如果服务器已经在运行，则使用下面提到的命令将其关闭，然后重新启动
redis-cli #shutdown #to stop the server
redis-server #to start the server again