Logging in MVC Part 5 – The Model and Data Layer

Introduction

This is the 5th article in a series on MVC logging.
Our sample website now has Elmah, NLog, Log4Net and Health monitoring set up and working. Now it is time to start work on our log reporting website by tying them all together.

Preparing the database

ASP.NET Health Monitoring logs a lot of different types of messages but there is no way to differentiate whether a message is just for information purposes or whether it is an error message that may need attention. So to address this issue, let’s create a new table called “aspnet_WebEvent_ErrorCodes” and introduce a column called “Level” which will map each message eventcode to either “Info”, “Error”.
The reason for doing this is so that we have a common “Level” attribute that we can use for all of our logging providers and this will allow us to later on filter all messages by their Log Level. Elmah for example will only be used to log unhandled exceptions so the LogLevel for our Elmah messages will always be “Error”.
Here is the database script necessary to add the new table to our database:

/****** Object:  Table [dbo].[aspnet_WebEvent_ErrorCodes]   

Script Date: 07/29/2010 09:56:45 ******/
IF  EXISTS (SELECT * FROM sys.objects 

WHERE object_id = OBJECT_ID(N'[dbo].[aspnet_WebEvent_ErrorCodes]') 

AND type in (N'U'))
DROP TABLE [dbo].[aspnet_WebEvent_ErrorCodes]
GO
/****** Object:  Default [DF_aspnet_WebEvent_ErrorCodes_Level]    

Script Date: 07/29/2010 09:56:45 ******/
IF  EXISTS (SELECT * FROM sys.default_constraints 

WHERE object_id = OBJECT_ID(N'[dbo].[DF_aspnet_WebEvent_ErrorCodes_Level]') 

AND parent_object_id = OBJECT_ID(N'[dbo].[aspnet_WebEvent_ErrorCodes]'))
Begin
IF  EXISTS (SELECT * FROM dbo.sysobjects 

WHERE id = OBJECT_ID(N'[DF_aspnet_WebEvent_ErrorCodes_Level]') AND type = 'D')
BEGIN
ALTER TABLE [dbo].[aspnet_WebEvent_ErrorCodes] 

DROP CONSTRAINT [DF_aspnet_WebEvent_ErrorCodes_Level]
END

End
GO

Logging in MVC Part 4 – Log4Net

Introduction

In this article we will quickly add Log4Net into the website so that later on we can decide whether to use Log4Net or NLog to log our custom messages.
Log4Net is a very widely used logger and it is quite likely that you have 3rd party dependencies in your website that already use Log4Net so it can be a good idea to track any messages that it logs.

Log4Net

The steps we need to follow are:
1. Download Log4Net
2. Add a reference to Log4Net
3. Add a table in our database to store the Log4Net logs
4. Modify the web.config file for Log4Net
5. Implement a Log4NetLogger that implements our ILogger interface.

Logging in MVC Part 3 – NLog

Introduction

In the previous article we implemented Health Monitoring into our MVC website.
Now we need to provide a way to log our own custom messages so that we can keep track of important events that occur throughout our website.
For example, you may need to log information before and after a financial transaction has occurred on your eCommerce website.
It is easy to write your own logger but as there are already many established logging frameworks already available for .NET I’ve decided to concentrate on 2 of the most popular ones: Log4Net and NLog.
In this article we will concentrate on setting up NLog and in the next article we will take a look at Log4Net.

NLog

Prior to working on this series I had never ever used NLog - I’ve always used Log4Net. However, after spending some time on Rob Connerys blog and looking at his MVC Storefront series and his MVC starter kit I decided to look at NLog so that I have another logging framework in my utility belt. It’s always good to broaden your knowledge and learn a new skill or master a new toolkit.
So what follows is pretty much exactly what Rob Conery did for his MVC starter kit website. However I have extended the default NLog functionality by including 2 new layout renderers.
Here are the steps we need to take to integrate NLog into our website:
1. Download NLog.
2. Create a table in our database to store the NLog messages.
3. Configure our NLog configuration file.
4. Set up a logging interface for our website.
5. Implement an NLog logger that uses our interface to log messages to the database table in step 2.
6. Add some additional layout renders that we will need for NLog.
Let’s tackle each one in order.

Logging in MVC Part 2 – Health Monitoring

Introduction

This is the second article in a series. The first article showed how to set up ELMAH to run on an MVC website.
The main focus of ELMAH is to log unhandled exceptions but there are many events that it can’t log for us. That is where ASP.NET Health monitoring comes in!

Health Monitoring

To log such things as when a website starts up, shuts down, recompiles etc the best tool to use is ASP.NET Health Monitoring. Health monitoring is closely tied to the ASP.NET runtime and can log many events that happen on your website:
For those not familiar with what Health Monitoring here is a list of events that can be tracked using it:
* Application starts and stops
* Failed logins and unhandled exceptions
* “Heartbeats”
* Successful and failed login attempts through Membership
* Successful and failed URL and ACL authorizations by authenticated users
* Valid and expired forms authentication tickets
* View state validation failures
* Compilation errors
* Configuration errors
* Unhandled exceptions
* Request validation failures
* Anything that causes request to abort
* Requests queued, processing, or rejected
* Specific or periodic monitoring event
* Process start time and more
One of the best articles to get started with Health Monitoring is the official page here:
http://www.asp.net/hosting/tutorials/logging-error-details-with-asp-net-health-monitoring-cs

Logging in MVC Part 1- Elmah

Introduction

Logging is one of the most useful services that every production website should have.
When errors occur on your website you should be notified about them. Whilst you may think you have written perfect code and unit tested everything to the best of your ability errors can and will still happen. The database server may go down, a 3rd party website may be offline, the shared hosting environment of your website may suffer an outage, a previously undetected bug may occur and the list goes on.
Having a great logging system in place allows you to stay on top of errors when they do happen.
In this series we will be building a logging reporting system that will allow you to drill into the various events that get logged on your website.
Before we get started let’s take a look at the finished solution:

and we would also like to see some graphs so we can quickly pinpoint when errors occurred on our website:

Understanding ASP.NET MVC (Model View Controller) Architecture for Beginners

Introduction

This article is intended to provide basic concepts and fundamentals of ASP.NET MVC (Model View Controller) architecture workflow for beginners.
“M” “V” “C” stands for “MODEL” “VIEW” “CONTROLLER”. ASP.NET MVC is an architecture to develop ASP.NET web applications in a different manner than the traditional ASP.NET web development. Web applications developed with ASP.NET MVC are even more SEO (Search Engine) friendly.
Developing ASP.NET MVC application requires Microsoft .NET Framework 3.5 or higher.

MVC Interaction with Browser

Like a normal web server interaction, MVC application also accepts requests and responds to the web browser in the same way.