问题

你能用thin吗？与 ActionController::Live实现服务器端事件(SSE)和长轮询？如果是，怎么办？

上下文

虽然标题是How to get Rails 4 ActionController::Live streaming working with Thin and Ruby 2? And how do Thin and Puma scale with live streaming?的重复, OP 通过问两个问题混淆了水域，这个问题从未得到回答。

许多其他帖子建议您可以使用 thin对于服务器端事件 (sse)，如果您通过 exec thin start --threaded 启动它: Does Heroku support ActionController::Live?和 Is puma the ONLY multi-threaded rails 4 http server? , Aaron 的开创性 http://tenderlovemaking.com/2012/07/30/is-it-live.html和 Ryan 永远可靠的 http://railscasts.com/episodes/401-actioncontroller-live?view=asciicast .但是即使我正在复制 Railscast 示例，我也无法让它与 thin 一起工作。 .

我尝试过的

# ----------------------------------------------------------------
# file: config/routes.rb
Rails.application.routes.draw do

  resources :widgets do
    collection do
      get 'events'              # SSE test
    end
  end
end

_

# ----------------------------------------------------------------
# file: config/environments/development.rb
Rails.application.configure do
    ... snip ...
    # see http://tenderlovemaking.com/2012/07/30/is-it-live.html
    config.preload_frameworks = true
    config.allow_concurrency = true
end

_

# ----------------------------------------------------------------
# file: app/controllers/widgets_controller.rb
class WidgetsController < ApplicationController
  include ActionController::Live

  # GET /widgets/events
  # see http://railscasts.com/episodes/401-actioncontroller-live?view=asciicast
  def events
    # SSE expects the `text/event-stream` content type
    response.headers['Content-Type'] = 'text/event-stream'
    3.times do |n|
      response.stream.write "#{n}...\n\n"
      sleep 2
    end
  ensure
    response.stream.close
  end

end

_

# ----------------------------------------------------------------
# Gemfile
source 'https://rubygems.org'

gem 'rails', '4.1.8'
gem 'pg'
... snip ...
gem 'thin'

运行它

在 shell 窗口 A 中:

$ bundle install
Chalcedony[~/Projects/heroku-sample/widget-worker]$ thin start --threaded --trace
Using rack adapter
Thin web server (v1.6.3 codename Protein Powder)
Tracing ON
Maximum connections set to 1024
Listening on 0.0.0.0:3000, CTRL+C to stop

然后在 shell 窗口 B 中:

$ curl --no-buffer localhost:3000/widgets/events

回到 shell 窗口 A，我看到请求和响应以一秒的间隔吐出(0... 和 1... 和 2... 之间有一秒的延迟)。这很好:

GET /widgets/events HTTP/1.1
User-Agent: curl/7.37.1
Host: localhost:3000
Accept: */*


HTTP/1.1 200 OK
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Cache-Control: no-cache
Content-Type: text/html; charset=utf-8
X-Request-Id: 95e64eb6-ee21-4e97-a33a-dbf579b3027c
X-Runtime: 0.066925
Connection: close
Server: thin


0... <delay...>


1... <delay...>


2... <delay...>

但是在 shell 窗口 B 中，打印输出被延迟并且一次全部出现。当我在 Chrome 中查看页面时，也会发生同样的事情。我是否没有正确配置某些设置？

附注:

$ rake about
About your application's environment
Ruby version              2.1.4-p265 (x86_64-darwin14.0)
RubyGems version          2.2.2
Rack version              1.5
Rails version             4.1.8
JavaScript Runtime        JavaScriptCore
Active Record version     4.1.8
Action Pack version       4.1.8
Action View version       4.1.8
Action Mailer version     4.1.8
Active Support version    4.1.8
Middleware                Rack::Sendfile, ActionDispatch::Static, #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x007fb0cb4ae1a0>, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, Rack::Head, Rack::ConditionalGet, Rack::ETag
Environment               development
Database adapter          postgresql
Database schema version   20141213003938

附言

现在您可能在想“您为什么不像其他人一样使用 puma？”好问题。现在，由于我还没有弄清楚的原因，我无法在我的机器上构建 puma gem。我一直在使用 thin在我的大多数 heroku 部署的应用程序中，所以我对此很满意。如果我不能瘦下来工作，我会把更多的精力放在打造 puma 上。

最佳答案

遗憾的是，您不能将 AC::Live 与 Thin 一起使用。这是马克explaining why以及有哪些替代方案。

关于ruby-on-rails - 如何让 ActionController::Live streaming 与 Thin 一起工作？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27464994/