ASP.NET MVC Mini-Profiler - Linq to SQL

This is a useful free profiler for ASP.NET MVC from the people at StackOverflow.com.

Some advice re. usage is in my previous post.

This post shows one way to use it in ASP.NET MVC with Linq to SQL.

In A DbRepository

I'm assuming a repository-based approach similar to NerdDinner.

I usually let my repository classes share a 'DataContext' - each controller typically has a main repository which creates the data context as usual, but other repositories needed in the controller actions are created using the second constructor below, and therefore use the first repository's data context.

    public class MyDbRepository : IMyRepository
    {
        public MyDataContext DataContext { get; protected set; }

        // Constructors.

        public MyDbRepository()
        {
            MiniProfiler profiler = MiniProfiler.Current;

            // Grab the SQL connection string (or could get it from web.config, for example).
            DataContext = new MyDataContext();
            string connString = DataContext.Connection.ConnectionString;

            // Setup a profiled connection.
            var conn = new SqlConnection(connString);
            var profiledConn = MvcMiniProfiler.Data.ProfiledDbConnection.Get(conn, profiler);

            // Create another data context using the profiled connection.
            DataContext = new MyDataContext(profiledConn);
        }

        public MyDbRepository(IMyRepository repos)
        {
            // Repositories can share a data context object.
            DataContext = repos.DataContext;
        }

        // Public methods.

        // +++

    }

ASP.NET MVC Mini-Profiler - First Impressions

This is a useful free profiler for ASP.NET MVC from the people at StackOverflow.com (a wonderful source of answers, and built using ASP.NET MVC).

The easiest way to install it in VS2010 is using NuGet

These snippets show one way to use it.

Site.Master (.ASPX view engine)

<script src="<%: Url.Content("https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js") %>"  type="text/javascript"></script>
<%= MvcMiniProfiler.MiniProfiler.RenderIncludes() %> 

Global.asax.cs

A simple approach is to start and stop the profiler for each separate web request, for example:

using MvcMiniProfiler; 

    public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_BeginRequest()
        {
            if (Request.IsLocal)
                MiniProfiler.Start();
        }
        
        protected void Application_EndRequest()
        {
            if (Request.IsLocal)
                MiniProfiler.Stop();
        }
    }

In A Controller, for example

Create a separate MiniProfiler 'step' for any long processing steps that you want to profile:

var profiler = MiniProfiler.Current;
 
    // No need to check 'profiler' for null here, it's handled in profiler.Step()

    using (profiler.Step("Search"))
    {
        // Time-consuming stuff...
        DoLongSearch(xxx);
    }

Steps can be nested, and the profile output will show the step structure:

    using (profiler.Step("SearchAndUpdate"))
    {
        using (profiler.Step("Search"))
        {
            // Time-consuming stuff...
            DoSearch(xxx);
        }

        using (profiler.Step("Update"))
        {
            // Time-consuming stuff...
            DoUpdate(xxx);
        }
    }

Viewing the Output

When you navigate to a URL that causes the profiler to be called, the resulting view will contain a small MiniProfiler gadget at the top left. Click on it to get the timing detail.

Linq to SQL

You can use the MiniProfiler to profile database calls, including Linq to SQL - see this post. The profile information includes the elapsed time of each query and also warns of 'duplicate' SQL queries, both of which can help in optimizing application design.