public static void RecordCacheMetric(int pagesLoaded)
{
    EventMetricDefinition cacheMetric;
 
    //so we can be called multiple times we want to see if the definition already exists.
    if (EventMetricDefinition.TryGetValue("LoupeSample", "Database.Engine", "Cache", out cacheMetric) == false)
    {
        cacheMetric = new EventMetricDefinition("LoupeSample", "Database.Engine", "Cache");
 
        //add the values (that are part of the definition)
        cacheMetric.AddValue("pages", typeof(int), SummaryFunction.Average, "Pages", "Pages in Cache", "Total number of pages in cache");
        cacheMetric.AddValue("size", typeof(int), SummaryFunction.Average, "Bytes", "Cache Size", "Total number of bytes used by pages in cache");
 
        //and now that we're done, we need to register this definition.  This locks the definition
        //and makes it go live.  This is passed by ref because if another thread registered the same metric, we'll get the
        //true registered object (whoever won the race), not necessarily the one we've just created to pass in.
        EventMetricDefinition.Register(ref cacheMetric);
    }
 
    //Now we can get the specific metric we want to record samples under (this is an instance of the definition)
    EventMetric cacheEventMetric = EventMetric.Register(cacheMetric, null);
 
    //now go ahead and write that sample.
    EventMetricSample newSample = cacheEventMetric.CreateSample();
    newSample.SetValue("pages", pagesLoaded);
    newSample.SetValue("size", pagesLoaded * 8196);
    newSample.Write();
}

/// <summary>
/// Record an event metric using an object
/// </summary>
/// <param name="pagesLoaded"></param>
public static void RecordCacheMetricByObject(int pagesLoaded)
{
    CacheEventMetric sample = new CacheEventMetric(pagesLoaded);
    EventMetric.Write(sample);
}
 
//The above code relies on the following class being defined.
 
/// <summary>
/// Log event metrics using a single object
/// </summary>
[EventMetric("LoupeSample", "Database.Engine", "Cache - Declarative", Caption = "Simple Cache", Description = "Performance metrics for the database engine")]
public class CacheEventMetric
{
    public CacheEventMetric(int pagesLoaded)
    {
        Pages = pagesLoaded;
        Size = pagesLoaded * 8192;
    }
 
    [EventMetricValue("pages", SummaryFunction.Average, "Pages", Caption = "Pages in Cache", Description = "Total number of pages in cache")]
    public int Pages { get; private set; }
 
    [EventMetricValue("size", SummaryFunction.Average, "Bytes", Caption = "Cache Size", Description = "Total number of bytes used by pages in cache")]
    public int Size { get; private set; }
}