The <dialog> element originally entered the HTML5 scene as a way to markup conversations but it was cut from the spec back in 2009. However now it’s back, and it has a brand new role.

The new <dialog> element makes it really easy for developers to create popup dialogs and modals for their web applications. Before now this required using a JavaScript plugin. However popup dialogs have become so popular that the Chrome team have decided to create a native implementation of this UI component.

In this blog post I’m going I take you on a tour of the new <dialog> element and show how it’s going to make your life a lot easier in the future.

Enabling Support For <dialog> in Chrome Canary

The title of this blog post says preview because the <dialog> element is currently only supported in Chrome Canary, and even then you have to enable a flag to use it.

If you want to try out the demos in this post make sure that you have Chrome Canary installed on your computer.

Enable Experimental Web Platform Features Flag

Once you have Chrome Canary installed go to chrome://flags and enable the Enable experimental Web Platform features flag. You will need to restart the browser for the change to take effect.

The New <dialog> Element

To define a new dialog you just need to add a <dialog> element somewhere in you HTML markup. Any HTML that is placed between the two tags will be displayed in the dialog.

<dialog id="dialog">
      <p>Hi, I'm a dialog!</p>
      <button id="close">Okay</button>
    </dialog>

Once you have defined your dialog you can show it using methods provided by the HTMLDialogElement interface. Lets take a look at that next.

The HTMLDialogElement Interface

The HTMLDialogElement interface provides a number of methods and properties that can be used to show and hide your dialogs. These can be called directly on your <dialog> elements.

var dialog = document.getElementById('#dialog');
    dialog.show();

The browser will take care of correctly positioning your dialog when it is launched. You can override this if you want to using CSS. We’ll take a look at how to do that later on.

The current implementation of the HTMLDialogElement interface includes support for a pending dialog stack. This means that you can queue multiple dialogs that will be displayed to the user individually.

Methods

The HTMLDialogElement interface provides methods for showing and closing dialogs. These are:

• show() – Used to launch a dialog. The user will still be able to interact with other elements on the page whilst the dialog is visible.
• showModal() – The showModal() method will also launch a dialog. This method however, will prevent the user from interacting with anything other than the dialog. This is similar to how traditional alerts work.
• close() – This method will close a dialog. You can optionally pass in a returnValue parameter which will update the returnValue property on the dialog.

Properties

The HTMLDialogElement interface has two unique properties.

• returnValue – This property is used to retrieve the value passed into close().
• open – This is a boolean value that will be set to true when the dialog is visible.

Events

A close event will be fired when the dialog is closed. You can listen out for this using a standard event listener on the dialog.

dialog.addEventListener('close', function(e) {
      // Do something.
    });

Creating Dialogs

An Example Dialog

See the Demo Download The Code View on CodePen

Now that you’ve learnt about the <dialog> element and the interface that backs it up, lets take a look at a few examples.

First we are going to see how to launch a simple dialog. The HTML here just includes a simple <dialog> element with some text and a close button. We’ve also included a button that will be used to launch the dialog.

<dialog id="dialog">
      <p>Hi, I'm a dialog!</p>
      <button id="close">Okay</button>
    </dialog>
    
    <button id="show">Show Dialog</button>

The JavaScript for this example is pretty straight-forward. We start by getting references to the dialog, and the show and cancel buttons. Next we setup an event listener that will call show() on the dialog when the show button is clicked. Finally we setup an event listener that will close the dialog when the close button is clicked.

var dialog = document.getElementById('dialog');
    var showBtn = document.getElementById('show');
    var closeBtn = document.getElementById('close');
    
    // Setup an event listener for the show button.
    showBtn.addEventListener('click', function(e) {
      e.preventDefault();
    
      // Show the dialog.
      dialog.show();
    });
    
    // Setup an event listener for the close button.
    closeBtn.addEventListener('click', function(e) {
      e.preventDefault();
    
      // Close the dialog.
      dialog.close();
    });

Creating Modal Dialogs

An Example Modal Dialog

See the Demo Download The Code View on CodePen

Creating modals is almost identical to how you create dialogs. The only difference is that you should use the showModal() method rather than show() to launch your dialog.

The HTML code here only has a few small changes to the text.

<dialog id="modal">
      <p>Hi, I'm a modal!</p>
      <button id="close">Okay</button>
    </dialog>
    
    <button id="show">Show Modal</button>

Here is the JavaScript code for the demo. Notice the use of showModal() rather than show().

var modal = document.getElementById('modal');
    var showBtn = document.getElementById('show');
    var closeBtn = document.getElementById('close');
    
    // Setup an event listener for the show button.
    showBtn.addEventListener('click', function(e) {
      e.preventDefault();
    
      // Show the modal.
      modal.showModal();
    });
    
    // Setup an event listener for the close button.
    closeBtn.addEventListener('click', function(e) {
      e.preventDefault();
    
      // Close the modal.
      modal.close();
    });

Styling Dialogs With CSS

A Styled Modal Dialog and Backdrop

See the Demo Download The Code View on CodePen

You style your dialogs just as you would any other element. The browser will automatically position the dialog in the center of the viewport. You can override this behaviour using the top, bottom, left and right properties if desired.

dialog {
      background: #FFF;
      width: 300px;
      text-align: center;
      padding: 1.5em;
      margin: 1em auto;
      border: 0;
      border-top: 5px solid #69c773;
      box-shadow: 0 2px 10px rgba(0,0,0,0.8);
    }

When using modal dialogs you can also style a backdrop in order to communicate to the user that interactions with the main page have been disabled. To do this you use the ::backdrop pseudo-element. You can then use standard CSS properties to position and style the backdrop.

dialog::backdrop {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background-color: rgba(0, 0, 0, 0.8);
    }

Note: The ::backdrop pseudo-element only works on dialogs launched using showModal().

Final Thoughts

It’s still early days for the reincarnated <dialog> element but I think it will become very popular amongst front-end web developers as time rolls on. Eliminating the need for a plugin to create dialogs helps to reduce page load times, as well as just making things easier for us developers.

The Chrome team have developed a polyfill that adds support for the <dialog> element to other browsers. That being said, I’d be cautious about using <dialog> in any important projects just yet.

I think it’s great to see browser vendors creating native implementations of some of the most frequently used UI components.

What are your thoughts about the <dialog> element? Do you think that browser vendors should be implementing these things, or are we better off with plugins?

Useful Links

• Polyfill for the <dialog> element
• WHATWG Specification For The <dialog> Element
• <dialog> element: Modals made easy

The post A Preview of The New Dialog Element appeared first on Treehouse Blog.

I remember working on a Rails app a few years ago and someone floated the idea of using this new service that had appeared on the scene. It was called New Relic and they were promising to give you more insight into the performance of your Rails app, than you ever could get before. We gave it a try and it was impressive, more importantly it was something the Ruby web development ecosystem truly needed.

Fast forward to now and you’d be hard-pressed to find a Ruby web application that doesn’t have New Relic hooked in. New Relic as a company has continued to provide tools to monitor your Ruby apps, but they’ve also branched out into a number of other languages such as Java, Python and even .Net. But of course as the number of features you provide grows so does the complexity and the amount of documentation out there. It becomes hard to figure out where to start especially if you’re not yet an expert.

Today I thought we could go back to the roots of New Relic and look at how we can get started with the service to monitor a Rails application.

A Basic Rails App

In order to use New Relic we need something to monitor, so let’s set up a basic ‘Hello World’ Rails app.

The app we create will live under ~/projects/tmp/newrelic, and will be called newrelic_rails1. I assume you already have Rails installed:

cd ~/projects/tmp/newrelic
    rails new newrelic_rails1
    cd newrelic_rails1

There isn’t much for us to do to create our ‘Hello World’ app. We need a new controller:

rails g controller hello

Now we just need a route, we will get the root route of the application to use our controller. We also need a view, with the words ‘Hello World’. Given all this, our config/routes.rb should look like this:

NewrelicRails1::Application.routes.draw do
      root 'hello#index'
    end

Our controller (app/controller/hello_controller.rb), will be as follows:

class HelloController > ApplicationController
      def index
      end
    end

And our view (app/views/hello/index.html.erb), will be similar to:

<h1>Hello World!</h1>
    

We can now start up our development server:

rails s

When we curl localhost:3000, we get:

<!DOCTYPE html>
    <html>
    ...
    <body>
    <h1>Hello World!</h1>
    </body>
    </html>

Everything is working!

Hooking in New Relic

With Ruby it’s very simple. We add a gem to our Gemfile, run a bundle install, drop a config file into the config folder and we have all we need. In fact, New Relic is pretty good at guiding you through this. All you need to do is log in to your account and if you haven’t deployed a New Relic agent before, it’s pretty obvious what to do:

Firstly, we install the New Relic agent gem by adding it to our Gemfile, as per the instructions:

Our Gemfile will now look like this:

source 'https://rubygems.org'
    
    gem 'rails', '4.0.0'
    gem 'sqlite3'
    gem 'sass-rails', '~> 4.0.0'
    gem 'uglifier', '>= 1.3.0'
    gem 'coffee-rails', '~> 4.0.0'
    gem 'jquery-rails'
    gem 'turbolinks'
    gem 'jbuilder', '~> 1.2'
    
    group :doc do
      gem 'sdoc', require: false
    end
    
    gem 'newrelic_rpm'
    

Whenever we add anything to the Gemfile we need to run:

bundle install

We also need a newrelic.yml, which you can download from New Relic:

It will come pre-configured with your license key. We need to put this file under config/newrelic.yml.

At this point if we ran our application in staging or production mode, we would already get data in our New Relic account. So let us do so:

RAILS_ENV=production rails s

This time when we curl localhost:3000, we get:

<!DOCTYPE html>
    <html>
    <head><script type="text/javascript">var NREUMQ=NREUMQ||[];NREUMQ.push(["mark","firstbyte",new Date().getTime()]);</script>
      <title>NewrelicRails1</title>
      <link data-turbolinks-track="true" href="/stylesheets/application.css" media="all" rel="stylesheet" />
      <script data-turbolinks-track="true" src="/javascripts/application.js"></script>
      <meta content="authenticity_token" name="csrf-param" />
    <meta content="i5rBPaG52bzM5Kn0SJwIbq6Qz0dG0KsIlcd8tb9vMV8=" name="csrf-token" />
    </head>
    <body>
    
    <h1>Hello World!</h1>
    
    <script type="text/javascript">if (typeof NREUMQ !== "undefined") { if (!NREUMQ.f) { NREUMQ.f=function() {
    NREUMQ.push(["load",new Date().getTime()]);
    var e=document.createElement("script");
    e.type="text/javascript";
    e.src=(("http:"===document.location.protocol)?"http:":"https:") + "//" +
      "js-agent.newrelic.com/nr-100.js";
    document.body.appendChild(e);
    if(NREUMQ.a)NREUMQ.a();
    };
    NREUMQ.a=window.onload;window.onload=NREUMQ.f;
    };
    NREUMQ.push(["nrfj","beacon-3.newrelic.com","b9119aa82e","2507356","cglYTRENCF4ERBtZB10KWRYKDABXGQ==",0,21,new Date().getTime(),"","","","",""]);}</script>
    
    <p></body>
    </html>
    

There is a bunch of JavaScript that got inserted into our pages so that New Relic can monitor browser time. This is one way we can tell that our New Relic integration is working. But it is not the only way, New Relic also creates a log file:

% cat log/newrelic_agent.log
    
    Logfile created on 2013-09-22 16:23:13 +1000 by logger.rb/36483
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Starting the New Relic agent in "production" environment.
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : To prevent agent startup add a NEWRELIC_ENABLE=false environment variable or modify the "production" section of your newrelic.yml.
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Reading configuration from config/newrelic.yml
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Enabling the Request Sampler.
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Environment: production
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Dispatcher: webrick
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Application: My Application
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Installing ActiveRecord 4 instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Installing Net instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Installing deferred Rack instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Installing Rails 4 Controller instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Installing Rails 4 view instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Installing Rails4 Error instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Finished instrumentation
    [09/22/13 16:23:13 +1000 skorks-envato (12424)] INFO : Doing deferred dependency-detection before Rack startup
    [09/22/13 16:23:16 +1000 skorks-envato (12424)] INFO : Reporting to: https://rpm.newrelic.com/accounts/303380/applications/2507356
    

We can also check our New Relic account to make sure a new application has appeared for monitoring:

There are however a few things that are not so nice:

• Our application is named ‘My Application’
• We accepted all the default configuration values, which may not suit our app
• We had to launch our server in production mode (which is only possible cause it’s a brand new app that doesn’t rely on any external infrastructure)

So let us look at our newrelic.yml file in a little bit more detail to see how we can monitor our app performance exactly the way we want it.

Diving in to New Relic Configuration

First of all, the New Relic configuration file is extremely well commented and I encourage you to read the comments for the various configuration parameters to understand what all of them do.

Secondly, New Relic configuration is environment aware, and configuration for all environments is defined in the one newrelic.yml file, this is very similar to, how the Rails database.yml file works. We define a bunch of common configuration values and then override the relevant ones in the specific environment blocks e.g.:

common: &default_settings
      license_key: '<your licence key>'
      app_name: My Application
      monitor_mode: true
    
      ...
    
    development:
      <<: *default_settings
      monitor_mode: false
    
    test:
      <<: *default_settings
      monitor_mode: false
    
    production:
      <<: *default_settings
      monitor_mode: true
    
    staging:
      <<: *default_settings
      monitor_mode: true
    

We can instantly begin to see how we can fix some of the points that we raised above. If we don’t want to have to launch our app in production mode while we’re tweaking our configuration, all we have to do is enable monitoring in development mode (we will need to remember to switch this off when we’re happy with our configuration as we don’t want development data cluttering up our New Relic account).

development:
      <<: *default_settings
      monitor_mode: true
    

We should also override our application name for every environment that we have, to make sure they’re monitored separately and the application name makes sense:

  common: &default_settings
        license_key: '<your licence key>'
        app_name: newrelic_rails1
        monitor_mode: true
    
        ...
    
      development:
        <<: *default_settings
        monitor_mode: true
        app_name: newrelic_rails1 (Development)
    
      test:
        <<: *default_settings
        monitor_mode: false
        app_name: newrelic_rails1 (Test)
    
      production:
        <<: *default_settings
        monitor_mode: true
        app_name: newrelic_rails1 (Production)
    
      staging:
        <<: *default_settings
        monitor_mode: true
        app_name: newrelic_rails1 (Staging)
      

With just those configuration tweaks, when we start our server in development mode and curl localhost:3000:

We’re now monitoring our application in development mode and our app name is what we expect. If your application is saying that it’s not receiving any data, give it a minute, it takes a little while for the data to start coming through.

The next most interesting (and often the most confusing) configuration value is the Apdex T-value. Unlike most of the other configuration parameters, this value does not live in the newrelic.yml file, but is instead found in the settings for the application within New Relic:

If you want to tweak your Apdex T-value you have to do it here, but what is this parameter and what is the right value to put in it? Well, New Relic explains it in the following way:

Your application’s Apdex T-value is set to 0.5 seconds. That means requests responding in less than 0.5 seconds are satisfying (s), responding between 0.5 seconds and 2.0 seconds are tolerating (t), and responding in more than 2.0 seconds are frustrating (f).

Essentially, New Relic uses the Apdex value to gauge the health of your application as far as performance is concerned, so if many of the requests that are monitored by New Relic take longer than your Apdex value, New Relic will consider your application to be performing poorly and if you’ve set up alerts, will notify you of the fact. Basically, you have to figure out, how fast you want each server request to be fulfilled by your application, so if you’re OK with a backend request taking two seconds, you can set your Apdex value to 2.0, but if you need a response to be returned within 100ms then you should set your Apdex value to 0.1.

If you have a new application you may set the Apdex value to the performance you desire from your application. If your app is an existing one, you may have some metrics regarding how fast it is/should be performing, and you can be guided by that. All requests which are fulfilled by the server in less than the Apdex T-value will be considered by New Relic to be fine. All requests fulfilled within Apdex * 4 seconds will be considered tolerating (i.e. users can tolerate it). All responses that take longer than Apdex * 4 will be considered frustrating (frustrated users don’t tend to stick around). So, set your Apdex T-value in such a way that you actually get useful information out of it, the actual value depends on your domain and what you want to achieve (in terms of performance), there is no right or wrong answer.

We will set our Apdex T-value to 100ms (0.1), since all we have is a ‘Hello World’ app, and it should be able to return a response very quickly (even in development mode).

Even More New Relic Configuration

It was a little funny that most of the configuration comes from the newrelic.yml file, but the Apdex T-value is in the application settings, so New Relic now allows you to move all the configuration values from the YAML file into New Relic:

The advantage of this is that you don’t have to redeploy every time you want to tweak your configuration values, so it is definitely something worth considering. We will stick with the YAML file for now.

So what are some of the other useful New Relic parameters we should know about?

Well, there is a set of parameters dealing with the New Relic agent log file:

log_level: info
    log_file_path: 'log'
    log_file_name: 'newrelic_agent.log'

These have sensible defaults, but if we want the log file to go to a specific place or if we want to see more or less info in the file, we can easily control this. Since we’re just setting up New Relic we will set the log level to debug, to make sure we don’t miss any important information (when we deploy we may want to set it to warn, or even error).

We now get a wealth of information in the log file, which (if read carefully) can give us a lot of insights into how New Relic works:

% cat log/newrelic_agent.log</p>
    
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Starting the New Relic agent in "development" environment.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : To prevent agent startup add a NEWRELIC_ENABLE=false environment variable or modify the "development" section of your newrelic.yml.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Reading configuration from config/newrelic.yml
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Not in Rake environment so skipping blacklisted_rake_tasks check: uninitialized constant Rake
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Updating config (add) from NewRelic::Agent::Configuration::YamlSource. Results:
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : {...}
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Not in Rake environment so skipping blacklisted_rake_tasks check: uninitialized constant Rake
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Updating config (add) from NewRelic::Agent::Configuration::ManualSource. Results:
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : {...}
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Not in Rake environment so skipping blacklisted_rake_tasks check: uninitialized constant Rake
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Installed New Relic Browser Monitoring middleware
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Installed New Relic Agent Hooks middleware
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Agent is configured to use SSL
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Using JSON marshaller
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Transaction tracing threshold is 2.0 seconds.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Ignoring errors of type 'ActionController::RoutingError'
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Ignoring errors of type 'Sinatra::NotFound'
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Errors will be sent to the New Relic service.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Ignoring errors of type 'ActionController::RoutingError'
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Ignoring errors of type 'Sinatra::NotFound'
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : RequestSampler max_samples set to 1200
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Resetting RequestSampler
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Enabling the Request Sampler.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Environment: development
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Dispatcher: webrick
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Application: newrelic_rails1 (Development)
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : EnvironmentReport failed to retrieve value for "Plugin List": undefined method `plugins' for #<Rails::Application::Configuration:0x007fb232401a00>
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : EnvironmentReport failed to retrieve value for "JRuby version": uninitialized constant NewRelic::EnvironmentReport::JRUBY_VERSION
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : EnvironmentReport failed to retrieve value for "Java VM version": uninitialized constant NewRelic::EnvironmentReport::ENV_JAVA
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : EnvironmentReport ignoring value for "Rails threadsafe" which came back falsey: nil
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Creating Ruby Agent worker thread.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Creating New Relic thread: Worker Loop
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : New Relic Ruby Agent 3.6.7.152 Initialized: pid = 12925
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Connecting Process to New Relic: bin/rails
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Not in Rake environment so skipping blacklisted_rake_tasks check: uninitialized constant Rake
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Created net/http handle to collector.newrelic.com:443
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Sending request to collector.newrelic.com:443/agent_listener/12/1f69cbd2a641bde79bdb5eb4c86a0ab32360e1f8/get_redirect_host?marshal_format=json
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Installing ActiveRecord 4 instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Installing Net instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Installing deferred Rack instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Installing Rails 4 Controller instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Installing Rails 4 view instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Installing Rails4 Error instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Finished instrumentation
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Registered NewRelic::Agent::Samplers::CpuSampler for harvest time sampling.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : Registered NewRelic::Agent::Samplers::MemorySampler for harvest time sampling.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : NewRelic::Agent::Samplers::ObjectSampler not supported on this platform.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] DEBUG : NewRelic::Agent::Samplers::DelayedJobSampler not supported on this platform.
    [09/22/13 17:23:39 +1000 skorks-envato (12925)] INFO : Doing deferred dependency-detection before Rack startup
    [09/22/13 17:23:40 +1000 skorks-envato (12925)] DEBUG : Uncompressed content returned
    [09/22/13 17:23:40 +1000 skorks-envato (12925)] DEBUG : Created net/http handle to collector-1.newrelic.com:443
    [09/22/13 17:23:40 +1000 skorks-envato (12925)] DEBUG : Sending request to collector-1.newrelic.com:443/agent_listener/12/1f69cbd2a641bde79bdb5eb4c86a0ab32360e1f8/connect?marshal_format=json
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Uncompressed content returned
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Server provided config: {...}
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Not in Rake environment so skipping blacklisted_rake_tasks check: uninitialized constant Rake
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Updating config (add) from NewRelic::Agent::Configuration::ServerSource. Results:
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : {...}
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Wiring up Cross Application Tracing to events after finished configuring
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Connected to New Relic Service at collector-1.newrelic.com
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Agent Run       = 575257565.
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Connection data = {...}
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] INFO : Reporting to: https://rpm.newrelic.com/accounts/303380/applications/2507376
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Browser timing header: "<script type=\\"text/javascript\\">var NREUMQ=NREUMQ||[];NREUMQ.push([\"mark\",\"firstbyte\",new Date().getTime()]);</script>"
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Browser timing static footer: "if (!NREUMQ.f) { NREUMQ.f=function() {\nNREUMQ.push([\"load\",new Date().getTime()]);\nvar e=document.createElement(\"script\");\ne.type=\"text/javascript\";\ne.src=((\"http:\"===document.location.protocol)?\"http:\":\"https:\") + \"//\" +\n  \"js-agent.newrelic.com/nr-100.js\";\ndocument.body.appendChild(e);\nif(NREUMQ.a)NREUMQ.a();\n};\nNREUMQ.a=window.onload;window.onload=NREUMQ.f;\n};\n"
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Real User Monitoring is using JSONP protocol
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Reporting performance data every 60 seconds.
    [09/22/13 17:23:42 +1000 skorks-envato (12925)] DEBUG : Running worker loop
    [09/22/13 17:23:50 +1000 skorks-envato (12925)] DEBUG : Attempting to insert RUM header at beginning of head.
    

For example we can see that:

• We can switch off monitoring even if it’s switched on in the configuration file, by setting an environment variable NEWRELIC_ENABLE=false
• We can see that New Relic inserts a bunch of Rack middleware
• We’re using Webrick as our server, which is obviously in development mode, but in production it would be good to confirm that New Relic recognises the server that we’re using
• New Relic is sending data to collector.newrelic.com:443
• New Relic is sending data every 60 seconds
• Real user monitoring is done via JSONP

Very useful information when you’re trying to figure out how things hang together.

Most of the other configuration parameters are pretty self explanatory e.g.:

browser_monitoring:
      auto_instrument: true
    capture_params: false
    

The only other one to possibly be aware of is:

transaction_tracer:
      transaction_threshold: apdex_f

The transaction tracer captures detailed data about requests that take too long. The transaction threshold is normally a multiple (x4) of the Apdex value, but it is often useful to divorce these values from each other. You might be happy with an Apdex score of one second, but you may want to capture detailed data about requests that take 1.5 seconds or longer (instead of the four seconds or longer which would happen by default). So you can set this parameter separately:

transaction_tracer:
      transaction_threshold: 1.5

The New Relic Developer Mode

One of the configuration values you may have noticed was:

developer_mode: true

This should only be switched on in development (if at all). In development mode, New Relic agent will store performance data about the last 100 requests in memory. You can look at this data at any time by hitting the /newrelic endpoint of your running application:

I hardly ever use it, but it’s there if you need it.

Notifying New Relic of Deployments

Whenever you’re working on the performance of your application, it’s always good to know if a particular deploy has had a positive or negative effect on performance. For this purpose, you can notify New Relic every time you perform a deploy. This way if performance degrades or improves, you’ll be able to see which deploy was the culprit. New Relic provides Capistrano hooks to do this, but I prefer the command line way:

% newrelic deployments -a 'newrelic_rails1 (Development)' -e 'development' -u 'skorks' -r 'abc123'
    Recorded deployment to 'newrelic_rails1 (Development)' (2013-09-22 18:19:13 +1000)

The key thing is to correctly supply the application name as configured in the newrelic.yml file.

We will get nice lines on the relevant New Relic graphs to indicate when a deployment occurred.

Conclusion

You now know a whole lot about how New Relic works and how to start using it to monitor a Rails application. But configuring things properly is only half the battle, what kind of metrics will New Relic actually capture for you? And how can you use them to improve the performance of your application? We will look at some of these in a subsequent article. For now, have a go at configuring New Relic for your Rails application (you’ll get a free T-shirt) and if you have any questions don’t forget to leave a comment.

This conference is designed for new professionals, graduates students and undergraduate students looking to pursue careers in student affairs.

CONFERENCE SCHEDULE

9:30-10:30 am: Registration

West Village Commons-3rd Floor

10:30 am: Welcome and Conference Overview

10:45-11:40 am: Workshop Session I

·           -Researching and Applying to Graduate School

·            -Work-Life Balance

·            -Navigating Politics Without Losing Your Integrity

·           -Semester @ Sea and Study Abroad

·            -Social Media: Engaging your students

·           - Balancing Personal Style and a Career: Is there a place for me in     Student Affairs?

11:45-12:45 pm: Workshop Session II

·            -Student Affairs 101

·            -NODA and ACUHO-I Internships

·            -Supervision: skills, Strategies and Considerations

·            -Embrace Being a New Professional (1-4 years)

·            -Assessment: How to become an expert

·            -Networking and Collaboration, your greatest asset

·            -Avoiding the “Accidental Career” Creating a Professional Development   Plan

12:45-1:45 pm: Lunch

1:00 pm: Welcome Address with Deb Moriarty, President-NASPA Region II

1:15 pm: Keynote, Dr. Marijo Russel O’Grady, Dean of Students, Pace University

1:30-2:15 pm: Post-Lunch Caucus: Hot Topics

2:30-3:30 pm: Panel Presentation

·            -Types of Institutions

·            -Types of Graduate Programs

·            -Jobs You May not Have Considered

·            -Lesson Learned from Professionals in the Field

3:35-4:45 pm: Speed Networking

The 2nd Annual IvyPlus Symposium will be held March 13-15th, 2014 on the Harvard and MIT campuses.  Students are encouraged to apply from the sciences, social sciences and humanities. There will be 150 students selected to attend the conference.  Deadlines are currently mid-November.

More information will be coming soon and can be found at www.ivyplussymposium.com