Logging Framework, a good idea?

Question

First of all, apologies for the subjective sounding title. This is intended as a direct question.

At present I am working on a suite of tools:

• A C# Windows Service, to primarily maintain an Oracle database.
• A C# Windows Service, (which will be used on multiple node sites) to process content of the database.
• An ASP.NET web interface to facilitate management of the overall "system"

Currently the tho Windows Services have been developed as Console Applications (to ease debugging/development) and I am in the midst of converting these to Services. After testing for a couple days now with these services, I'm finding that I would like to increase the granularity of my logging. I'm finding that I miss Console.WriteLine() and I would like to provide an alternate log source like a flat-file for this type of output. This has lead me to think, "Should I be using a framework, or have I got enough?"

The reason I have mentioned the aspects I am developing is to provide insight to my situation. A "Core" DLL has been created, common across all components, abstracting the interaction layer between the applications and database. It is within this DLL that a class has been created which will attempt to "log to a table in the database" else on fail "log to local Event Log". This is it, that's the extent of logging.

Throughout the aforementioned tools, there are multiple instances of logging not dissimilar to:

Log.LogError("Code", e.Message + "\n" + e.StackTrace);

Although quite basic, this method does make use of reflection to Identify the source of the error.

My Question

Looking at my current logging solution it appears "sufficient" in terms of what it does and how it is integrated with all my solutions. However, I've been looking at logging frameworks (Notably log4net) and their features impress me. The ability to, if needed in the future, add another output format (such as an SMTP server) sounds kind of cool to me! :)

What I would like to know are the benefits of moving to a framework (like log4net)? The extent of how much I will have to adapt my code? Whether or not I am just looking at the greener grass on the other side? And finally, but probably most importantly, am I doing the right thing? Should I just add the ability to my Log class to "LogDebug" and be done with it? The last thing I would want to do is completely overhaul my suite, just for a "basic" feature, but if there are other benefits (to design, reliance, good practice? etc.) I'm interested.

Thanks,

Answer 1

Proper logging is especially beneficial when running code on multiple remote systems, as far as I recall, log4net will let you send your logs to a remote syslog server without much coding overhead (meaning you can view your logs from all machines in one centralized place) doing this will massively reduce the time it takes you to get information relating to a bug or problem with the system, and should also give you an indication of how prevalent the issue is.

As mentioned in other posts, log4net also allows for multiple appenders and multiple log levels, so determining where you want certain log information (i.e. in a database or in a local flat file, hey log4net even lets you spit logs out over telnet) to be stored is an absolute doddle.

As for implementing it, there are several good sites talking you through the setup. How you actually make use of the logging objects that log4net gives you is an architectural choice, but you could simply change the constructor of an object to take a log4net object and from within this object, just use the log4net object as you would Console.WriteLine.

I find the tutorial series here particularly useful, and it'll also go in to more depth than I can here about the benefits and the different ways of configuring log4net.

Answer 2

Yes. Using an existing, proven logging framework (such as Log4net) is a good idea.

Log4Net is configurable at runtime (great for tracking down issues in production code).

As a commenter pointed out, it's also very simple to use.

Answer 3

Yes, you definitely want to use a logging framework. A logging framework will allow you to:

• Set the logging levels for the different logger instances.
• Set the "appenders" or output for each of the different logger instances.

Perhaps, more importantly, if you use a logging framework, it is very easy to swap out one implementation of the logging framework for another (perhaps a null implementation that simply discards messages); whereas, if you write all your logging statements, directly, swapping out the implementation will be a nightmare.

Answer 4

I think you should use Log4net, simply because it's always better to reuse than to build your own thing. log4net has been used by a lot of developers and are pretty matured.

Think about your maintenance prospect; one or two months down the road, you might need to tweak your custom logging class a bit, to add some multithreading support etc. And when you are fixing the bugs arose from your logging class, you will miss Log4net.

Answer 5

Well one of the bigger benefits is not having to maintain the code yourself. Most of the time, logging frameworks have a lot more functionality than your own solution. Because they are so focused on logging, those frameworks usually are pretty complete in the both functionality and ways to implement it. And then there's reliability; there's nothing worse than a logging framework that's not logging anything because it's bugged. ;)

Take for example ELMAH for ASP.net applications. It also includes notifications, exports to various target formats, etc. Things that are pretty handy but you'll never build yourself unless you really need it.

How many changes to your code are needed obviously depends on both your code and the framework of choice. It's hard to say anything about that.

Answer 6

I am going to give a shout out to NLog (http://nlog-project.org/home) as it doesn't suffer from the 'Straight Java Port - then rewrite' syndrome of most oss .Net libs.

Some key benefits for us were the very fast Logger.IsFooEnabled (volatile read) and the overall performance of the system.

To each its own though, but I personally prefer NLog for my projects (and some of my clients too).

Cheers, Florian

Answer 7

The advantage of using a good logging framework like Log4Net is that they have a small impact upon your code in terms of lines of code that you have to alter (in other words you only have to alter each existing logging line).

Also, if you are concerned about altering your code if you change frameworks, or if you feel you want to roll your own, then you could always create your own interface to a logging framework. Then you only ever have to change your code in one place after that.

Answer 8

I think sysadmins expect services to log to the application event log in windows.

Look up System.Diagnostics.EventLog, although log4net will write to that too..

Answer 9

The initial statement in the log4j website might help in some of your questions, the underlying principles are the same of log4net:

With log4j it is possible to enable logging at runtime without modifying the application binary. The log4j package is designed so that these statements can remain in shipped code without incurring a heavy performance cost. Logging behavior can be controlled by editing a configuration file, without touching the application binary.

Using a logger hierarchy it is possible to control which log statements are output at arbitrarily fine granularity but also great ease. This helps reduce the volume of logged output and minimize the cost of logging.

In this case there's clearly no need to reinvent the wheel. Most Logging frameworks are somewhat straightforward, so the extend of changes will most likely depend on the size of your existing programs.

Answer 10

if you write your logger class properly it will be easily expendable to any of your needs. Any framework could impress you with many features but another framework is another variable in your debugging process as it can give you an error that does not exists or can make an error by itself in combination with your application. If you are ready to make beta testing for open source software project this is fine...

In your place i would write log class with ability to extend it features you find interesting to you project based on the list of features known frameworks have. I don't see any problem to log something to file and then send it over smpt, just one small function does the job.

Moreover, you can write your own class which will be pretty abstract and put your basic code in there, if you will ever need to use external framework for testing you class would be able to use it with minimal impact on code. Just take a look how there frameworks are implemented on the code level.

think of that you will need to learn how to properly use these frameworks when your only needs for now to log very small part of it...