#Varshaman - C# Implementation For Statsd As Cross Cutting Concern

Statsd is a state of the art measurement tool created by Etsy. It allows creation of graphs and metrics in unobtrusive way with minimal performance impact.

Varshaman is a C# wrapper for statsd that gives the ability to implement metrics creation as a cross cutting concern by integrating statsd excellent C# client statsd-csharp-client and PostSharp.

##PostSharp Licensing

Install PostSharp: http://visualstudiogallery.msdn.microsoft.com/a058d5d3-e654-43f8-a308-c3bdfdd0be4a.

This repo uses PostSharp Express, which is free for commercial uses (see http://www.postsharp.net/purchase for more details). However, you will need a license key to use PostSharp and it can be requested here: http://www.postsharp.net/Purchase/Review-Licensee.aspx.

Make sure you get it and feel the license key in PostSharp dialog on Visual Studio to avoid future problems.

##Usage

Use the Nuget package or clone this repo.

###Configuration

Make sure to configure the statsd server IP and port, as well as an optional application prefix, that will be embedded into all metrics sent by the application. This should be done once in the app start file:

var metricsConfig = new MetricsConfig
{
	StatsdServerName = //IP,
	StatsdServerPort = //port, most of the times 8125
	Prefix = //app-prefix,
};

Metrics.Configure(metricsConfig);

###Attributes Over Methods

Varshaman exposes 3 attributes that can decorate a given method:

• Timing - measures how much time took for a given method to be executed.
• Counter - counts how many time a given method was called.
• Gauge - constant value when a given method is called.

These 3 attributes makes calls statsd server and pass the relevant metrics data.

You can use metric collection as a cross cutting concern for your application:

[Timing("do-with-timing")]
public void DoWithTiming()
{

}

[Counter("do-with-counter")]
public void DoWithCounter()
{

}

[Gauge("do-with-gauge", 3)]
public void DoWithGuage()
{

}

###Wrapping Code Blocks

You can wrap specific code blocks for timing measurements:

//wrapping a code block
using (Metrics.StartTimer("wrapping-code-block"))
{
	//do something
}

//wrapping a Func
var result = Metrics.Time(() =>
{
	//some Func
}, "wrapping-func");

//wrapping an Action
Metrics.Time(() => //some Action), "wrapping-action");

###Direct Calls

You can call the metric collector directly using the Metrics static class:

Metrics.Counter("counter");
Metrics.Gauge("gauge", 2);
Metrics.Timer("timer", 23);

Note: The code was built for .Net 3.5.

Enjoy measuring!