Installing and Using Glimpse

To audit EF queries, we'll install and use a tool called Glimpse. 0:00 Once installed, Glimpse will give us the ability to easily inspect web requests, 0:04 including the EF queries that are executed. 0:09 To install Glimpse, we use the NuGet Package Manager. 0:11 Select the Browse tab and search for Glimpse. 0:16 Glimpse is the main base package, so we'll start with installing that. 0:21 When the Glimpse package is finished installing, it'll open a Readme file that 0:32 contains information on how to get started with using Glimpse. 0:36 To get the most out of using Glimpse with our web app, 0:42 we'll install two additional Glimpse packages. 0:44 The Glimpse EF6 package, for auditing Entity Framework queries and commands, and 0:47 the Glimpse Mvc5 package, for auditing events related to the MVC web framework. 0:52 Since the Glimpse EF6 package is right here in this list, 0:59 let's start with installing that. 1:03 Then, search for Glimpse.mvc, and 1:05 install the Glimpse.Mvc5 package. 1:09 Every time that you install a Glimpse related package, 1:15 the installer will inspect your Glimpse packages, and update the Readme file to 1:18 let you know if any are out of date, and need to be updated. 1:23 Looks like there's an update for the Glimpse.AspNet package. 1:27 Let's select the Updates tab, and update the package. 1:34 Now that we have all of the necessary packages installed, we can run our 1:43 application and configure Glimpse by browsing to the path glimpse.axd. 1:48 Glimpse.axd looks like it'd be a file in our project, but it's not, 1:53 it's a special path that maps to the Glimpse HTTP handler. 1:58 In the Web.config file that's located in the root of our project, 2:03 we can see the HTTP handler configuration that was added 2:07 when we installed the Glimpse NuGet package. 2:11 The way that ASP.NET handles processing requests can be customized through the use 2:13 of custom HTTP handlers or modules, Glimpse makes use of both. 2:18 For more information about HTTP handlers and modules, see the teacher's notes. 2:24 To enable Glimpse, we simply click the large Turn Glimpse On button. 2:30 Once the page is reloaded, we can see here on the right, 2:35 in this green box, that the Glimpse cookie is set to on. 2:39 An HTTP cookie is a little piece of data that the browser sends to the web server 2:45 on every request. 2:50 Glimpse uses a cookie to determine when it's enabled. 2:51 For more information on cookies, see the teacher's notes. 2:55 Now that we've enabled Glimpse, we can remove glimpse.axd from our path, 2:59 to return to our web app's home page. 3:03 And here's our home page, but notice here in the lower-right, 3:07 we now have the glimpse Heads-Up Display, or HUD, being displayed. 3:12 The glimpse HUD will give us some basic information about our request, 3:17 how long the request took to complete in milliseconds. 3:21 And a breakdown of how much time that was spent communicating between the client and 3:24 the server, processing on the server, and processing on the client. 3:28 We can also see a breakdown of the server processing time, 3:35 how much spent in the action method, and rendering the view. 3:39 We can also see which controller and action was called, and 3:44 just to right of that, how many database queries were ran, and how long they took. 3:47 We can hover over each section to get a quick look at some additional information. 3:53 Here's a closer look at the HTTP section, And the Host section. 3:57 Clicking on the g in the lower right-hand corner opens up the full Glimpse panel. 4:07 Glimpse gives you detailed information about the request. 4:14 For now, let's select the SQL tab, and take a look at 4:17 the information that Glimpse provides about EF queries and commands. 4:20 We can see that a single query was executed, and 4:25 how long it took to complete, and the SQL that EF generated for the query. 4:28 Let's look at another example by browsing to the ADD COMIC BOOK page. 4:35 Now, we can see that 3 queries were executed, and the total execution time. 4:43 Then, below that, we can see the SQL for each query, and 4:49 how long each took to execute. 4:52 Glimpse is a powerful, easy-to-use tool that can help you to not only understand 4:56 how a request is being processed, but how each part is performing. 5:01 We'll continue to use Glimpse throughout the rest of this workshop, 5:06 as we take a closer look at some common EF query performance issues. 5:09