I'm trying to use System.Diagnostics to do some very basic logging. I figure I'd use what's in the box rather than taking on an extra dependency like Log4Net or EntLib.
I'm all set up, tracing is working wonderfully. Code snippet:
Trace.TraceInformation("Hello World")
App.config:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.diagnostics>
<trace autoflush="true" indentsize="4">
<listeners>
<add name="TraceListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="Trace.log" traceOutputOptions="DateTime" />
<remove name="Default" />
</listeners>
</trace>
</system.diagnostics>
</configuration>
and my little "Hello World" shows nicely up in my Trace.log file. But now I'd like to switch OFF tracing, so I dig into MSDN and find How to: Configure Trace Switches
. I add the <switches> element, and now my app.config looks like this:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.diagnostics>
<trace autoflush="true" indentsize="4">
<listeners>
<add name="TraceListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="Trace.log" traceOutputOptions="DateTime" />
<remove name="Default" />
</listeners>
</trace>
<switches>
<add name="Data" value="0" />
</switches>
</system.diagnostics>
</configuration>
The value="0" should turn off tracing - at least if you then follow How to: Create and Initialize Trace Switches, which tells you to add this line of code:
Dim dataSwitch As New BooleanSwitch("Data", "DataAccess module")
That doesn't make sense to me: I just have to declare an instance of the BooleanSwicth to be able to manage (disable) tracing via the .config file? Should I like ... use ... the object somewhere?
Anyways, I'm sure I missed something really obvious somewhere. Please help.
How do I switch OFF tracing in app.config?
I agree with #Alex Humphrey's recommendation to try using TraceSources. With TraceSources you gain more control over how your logging/tracing statements execute. For example, you could have code like this:
public class MyClass1
{
private static readonly TraceSource ts = new TraceSource("MyClass1");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
public class MyClass2
{
private static readonly TraceSource ts = new TraceSource("MyClass2");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
The TraceSource.TraceEvent call will automatically check the level of the message (TraceEventType.Information) against the configured level of the associated Switch and will determine whether or not the message should actually be written out.
By using a differently named TraceSource for each type, you can control the logging from those classes individually. You could enable MyClass1 logging or you could disable it or you could enable it but have it log only if the level of the message (TraceEventType) is greater than a certain value (maybe only log "Warning" and higher). At the same time, you could turn logging in MyClass2 on or off or set to a level, completely independently of MyClass1. All of this enabling/disabling/level stuff happens in the app.config file.
Using the app.config file, you could also control all TraceSources (or groups of TraceSources) in the same way. So, you could configure so that MyClass1 and MyClass2 are both controlled by the same Switch.
If you don't want to have a differently named TraceSource for each type, you could just create the same TraceSource in every class:
public class MyClass1
{
private static readonly TraceSource ts = new TraceSource("MyApplication");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
public class MyClass2
{
private static readonly TraceSource ts = new TraceSource("MyApplication");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
This way, you could make all logging within your application happen at the same level (or be turned off or go the same TraceListener, or whatever).
You could also configure different parts of your application to be independently configurable without having to go the "trouble" of defining a unique TraceSource in each type:
public class Analysis1
{
private static readonly TraceSource ts = new TraceSource("MyApplication.Analysis");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
public class Analysis2
{
private static readonly TraceSource ts = new TraceSource("MyApplication.Analysis");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
public class DataAccess1
{
private static readonly TraceSource ts = new TraceSource("MyApplication.DataAccess");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
public class DataAccess2
{
private static readonly TraceSource ts = new TraceSource("MyApplication.DataAccess");
public DoSomething(int x)
{
ts.TraceEvent(TraceEventType.Information, "In DoSomething. x = {0}", x);
}
}
With your class instrumented this way, you could make the "DataAccess" part of your app log at one level while the "Analysis" part of your app logs at a different level (of course, either or both parts of your app could be configured so that logging is disabled).
Here is a part of an app.config file that configures TraceSources and TraceSwitches:
<system.diagnostics>
<trace autoflush="true"></trace>
<sources>
<source name="MyClass1" switchName="switch1">
<listeners>
<remove name="Default"></remove>
<add name="console"></add>
</listeners>
</source>
<source name="MyClass2" switchName="switch2">
<listeners>
<remove name="Default"></remove>
<add name="console"></add>
</listeners>
</source>
</sources>
<switches>
<add name="switch1" value="Information"/>
<add name="switch2" value="Warning"/>
</switches>
<sharedListeners>
<add name="console"
type="System.Diagnostics.ConsoleTraceListener">
</add>
<add name="file"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="trace.txt">
</add>
</sharedListeners>
</system.diagnostics>
As you can see, you could configure a single TraceSource and a single Switch and all logging would occur with a single level of control (i.e. you could turn all logging off or make it log at a certain level).
Alternatively, you could define multiple TraceSources (and reference the corresponding TraceSources in your code) and multiple Switches. The Switches may be shared (i.e. multiple TraceSources can use the same Switch).
Ultimately, by putting in a little more effort now to use TraceSources and to reference appropriately named TraceSources in your code (i.e. define the TraceSource names logically so that you can have the desired degree of control over logging in your app), you will gain significant flexibility in the long run.
Here are a few links that might help you with System.Diagnostics as you go forward:
.net Diagnostics best practices?
Logging best practices
What's the best approach to logging?
Does the .Net TraceSource/TraceListener framework have something similar to log4net's Formatters?
In the links I posted, there is often discussion of the "best" logging framework. I am not trying to convince you to change from System.Diagnostics. The links also tend to have good information about using System.Diagnostics, that is why I posted them.
Several of the links I posted contain a link to Ukadc.Diagnostics. This is a really cool add on library for System.Diagnostics that adds rich formatting capability, similar to what you can do with log4net and NLog. This library imposes a config-only dependency on your app, not a code or reference dependency.
You don't turn off tracing globally this way.
You have to
1) declare a switch and set its value:
<switches>
<add name="MySwitch" value="Information"/>
</switches>
2) associate this switch with a TraceSource you use:
<sources>
<source name="MySource" switchName="MySwitch"/>
</source>
So, whatever you write via TraceSource named "MySource" is filtered according to the switch value.
If you use static methods like Trace.Write, I suppose, you cannot use switches at all, because there is no TraceSource to apply the filter.
If you want to turn off tracing by static methods, just remove all the listeners: <listeners> <clear/> </listeners>.
Check the state of dataSwitch whenever you need to log, as per:
http://msdn.microsoft.com/en-us/library/aa984285%28v=VS.71%29.aspx
However, that is pretty nasty, having to put those checks everywhere. Is their a reason you don't want to simply remove the TraceListener from the listeners collection in app.config?
Apart from that, I'd investigate using the .NET 2.0+ trace stuff which includes TraceSource. The new(er) stuff offers a much higher degree of configuration, and you might find it's more suitable.
http://msdn.microsoft.com/en-us/library/ms228993.aspx
It´s the switchValue attribute of source node:
<system.diagnostics>
<sources>
<source name="System.ServiceModel"
switchValue="Off"
propagateActivity="true">
<listeners>
<add name="traceListener"
type="System.Diagnostics.XmlWriterTraceListener"
initializeData= "somePath" />
</listeners>
</source>
</sources>
<trace autoflush="true" />
Late joining with a quick footnote about the app.config, in case this saves a couple of days from the life of someone out there:
Assume you have the startup (.exe) projectA containing classA which makes use of projectB (.dll) containing classB.
ClassB in turn makes use of a new TraceSource("classB") instance. In order to configure it you need to modify the app.config or projectA. Tweaking the app.config of projectB won't lead anywhere.
Also note that the placement of the
<system.diagnostics>
Section inside app.config seems to be causing problems if placed before the section:
<configSections>
or after the section:
<userSettings>
At least in my case, I was getting errors when I attempted to place it in these locations in the app.config of my project. The layout that worked for me was:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
...config sections here if any...
</configSections>
<system.diagnostics>
<trace autoflush="true"/>
<sources>
<source name="classB"
switchName="mySwitch"
switchType="System.Diagnostics.SourceSwitch" >
<listeners>
<clear/>
<add name="textwriterListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="ClassBLog.txt"
traceOutputOptions="DateTime" />
</listeners>
</source>
</sources>
<switches>
<add name="mySwitch" value="Verbose" />
</switches>
</system.diagnostics>
<runtime>
...runtime sections here if any...
</runtime>
<userSettings>
...usersettings sections here if any...
</userSettings>
</configuration>
Try this simple solution. In example below, "SomeNoisyLibrary" is littering the log with many useless entries. We filter them with "when condition"
https://github.com/NLog/NLog/wiki/When-Filter
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
internalLogFile="../log/MyApplication.log"
autoReload="true" throwExceptions="true">
<targets async="true">
<target xsi:type="File"
name="file"
layout="${longdate} | ${level:uppercase=true} | ${logger} | ${message} ${exception:format=ToString}"
fileName="../log/MyApplication.${processid}.${shortdate}.log" keepFileOpen="false"
maxArchiveFiles="10"
archiveAboveSize="10024000"
archiveEvery="Day"
/>
<target xsi:type="ColoredConsole"
name="console"
layout="${longdate} | ${level:uppercase=true} | ${logger} | ${message}${exception:format=ToString}" />
</targets>
<rules>
<logger name="*" minlevel="Info" writeTo="file,console">
<filters defaultAction='Log'>
<when condition="equals('${logger}','SomeNoisyLibrary')" action="Ignore" />
</filters>
</logger>
</rules>
</nlog>
Related
I saw two answers about this topic but I can't figure out. I have a custom TextWriterTraceListener and I want it to use in my tracesource.
namespace MyTraceLogger
{
public class MyTextTraceListener : TextWriterTraceListener
{
public override void Write(string message)
{
this.Write(string.Format("{0},{1}",
DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),
message));
}
public override void WriteLine(string message)
{
this.WriteLine(string.Format("{0},{1}",
DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),
message));
}
}
}
<system.diagnostics>
<sources>
<source name="SpendingTrace" switchName="SpendingSourceSwitch" switchType="System.Diagnostics.SourceSwitch" >
<listeners>
<add name="Spending" type="MyTraceLogger.MyTraceLogger.MyTextTraceListener,MyTraceLogger.MyTraceLogger" initializeData="Spending.log" />
<remove name ="Default" />
</listeners>
</source>
</sources>
<switches>
<!-- You can set the level at which tracing is to occur -->
<add name="SpendingSourceSwitch" value="Warning" />
<!-- You can turn tracing off -->
<!--add name="SourceSwitch" value="Off" -->
</switches>
<trace autoflush="true" indentsize="4"></trace>
This is the error I get: Couldn't find type for class MyTraceLogger.MyTraceLogger.MyTextTraceListener,MyTraceLogger.MyTraceLogger.
When I right-click on MyTraceLogger's project for properties, it show assembly is MyTraceLogger and my namespace is also MyTraceLogger.
Why use configuration file and not instantiate it locally inside the code? In such way you will avoid config files being confused, moved or used incorrectly in the future development and maintenance.
Create an instance of your MyTextTraceListener and add it to trace listeners:
MyTextTraceListener myTraceListener = new MyTextTraceListener ("application.log");
Trace.Listeners.Add(myTraceListener);
Refer to this post too: How to define custom TraceListener in app.config
Why do you put the namespace twice? I think you would just need:
<add name="Spending" type="MyTraceLogger.MyTextTraceListener,MyTraceLogger" initializeData="Spending.log" />
This is how trace listener defined in app.config:
<system.diagnostics>
<trace autoflush="true" indentsize="4">
<listeners>
<add name="Listener" type="System.Diagnostics.TextWriterTraceListener" initializeData="Import.log" traceOutputOptions="None" />
<remove name="Default" />
</listeners>
</trace>
</system.diagnostics>
And the simple method that calls Trace.WriteLine:
public static void WriteLine(LogLevel logLevel, string message)
{
var message = String.Format("{0}", messageText);
Trace.WriteLine(message);
}
But as a result - there is no file created and messages there. I thought that the reason could be in method that is calling outside of assembly. But that looks impossible.
Is there any additional settings that I missed? Thanks in advance.
Actually the problem was in that the static method with logging was invoking from another assembly. There are two solutions I've figured out:
Make app.config copying after build (or copy manually) to the folder with assembly which contains
that method;
Declare diagnostics section with trace options in app.config of executing assembly.
So I'm using Tracesource to log some errors and wan't to create a log file in a users local windows document structure ( something like System.Environment.SpecialFolder.LocalApplicationData ).
However I have no idea if I can do anything like that inside a config file.
<system.diagnostics>
<trace autoflush="true"/>
<sources>
<source name="MainSource"
switchName="MainSwitch"
switchType="System.Diagnostics.SourceSwitch" >
<listeners>
<add name="LogFileListener" />
</listeners>
</source>
</sources>
<sharedListeners>
<add name="LogFileListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="This is the place the output file goes to"
traceOutputOptions="ProcessId, DateTime, Callstack" />
</sharedListeners>
<switches>
<add name="MainSwitch" value="Verbose" />
</switches>
</system.diagnostics>
initializeData is I think a parameter to the constructor and is where I would have to put a custom path.
The path to the logfile in the config file is absolute and cannot be assumed by any special variables.
However, you could create it dynamically and this should solve your issue
How to: Create and Initialize Trace Sources
Below is sample code I was using for my options. It could help you understand the schema.
Configuration exeConfiguration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
ConfigurationSection diagnosticsSection = exeConfiguration.GetSection("system.diagnostics");
ConfigurationElementCollection switches = diagnosticsSection.ElementInformation
.Properties["switches"]
.Value as ConfigurationElementCollection;
foreach (ConfigurationElement switchElement in switches)
{
Debug.WriteLine("switch: name=" +
switchElement.ElementInformation.Properties["name"].Value +
" value=" +
switchElement.ElementInformation.Properties["value"].Value);
}
I want to configure a FileTraceListeners in my application, that ignores 'verbose' level messages but logs 'information' level and above as well as 'start' and 'stop' events.
Everything is configured within the app.config file.
However I cannot find the correct syntax for combining these different trace levels.
The Syntax for filters is explained here.
Using a single filter for 'information' will correctly filter out everything that is not 'information', 'warning' 'error' or 'critical'. However I also want to include 'start' and 'stop' events.
I tried using 2 filters :
<filter type="System.Diagnostics.EventTypeFilter" initializeData="Information"/>
<filter type="System.Diagnostics.EventTypeFilter" initializeData="ActivityTracing"/>
I tried combining the initializeDate
with commas:
initializeData="Information,ActivityTracing"
or semicolons initializeData="Information;ActivityTracing"
everything will just cause a syntax error.
How do I combine these two filters inside app.config?
(I am using the native .net 3.5 logging libraries and do not wish to change to log4net or another framework at this point.)
My code looks like:
<filter type="System.Diagnostics.EventTypeFilter" initializeData="Warning,ActivityTracing"/>
and its works.
I didn't try to use the <filter> but recently setup something similar and was successful by using the <switches> and <sources> elements. Here's how I did it:
<system.diagnostics>
<trace autoflush="true" indentsize="2" />
<sources>
<source name="SyncService" switchName="infoactivity">
<listeners>
<clear />
<add name="file" />
</listeners>
</source>
</sources>
<switches>
<add name="none" value="Off" />
<add name="infoactivity" value="Information, ActivityTracing" />
<...>
</switches>
<sharedListeners>
<add name="file" type="System.Diagnostics.TextWriterTraceListener"
initializeData="sync.log" />
</sharedListeners>
</system.diagnostics>
Just change the switchName value to one of the defined switches to get the appropriate level of logging.
The code used a single static TraceSource wrapped up in a LogEvent smart enum class (I think I found an example on one of Jon Skeet's answers once).
public class LogEvent {
public static readonly LogEvent SyncStart = new LogEvent(1,
"Sync Service started on {0}", TraceEventType.Start);
public static readonly LogEvent SyncStop = new LogEvent(99,
"Sync Service stopped on {0}", TraceEventType.Stop);
public static readonly LogEvent SyncError = new LogEvent(501,
"\r\n=============\r\n{0}\r\n==============\r\n", TraceEventType.Error);
// etc
private readonly int id;
private readonly string format;
private readonly TraceEventType type;
private static readonly TraceSource trace = new TraceSource("SyncService");
private LogEvent(int id, string format, TraceEventType type)
{
this.id = id;
this.format = format;
this.type = type;
}
public void Log(params object[] data)
{
var message = String.Format(format, data);
trace.TraceEvent(type, id, message);
}
}
and in the service code I liberally sprinkled in logging statements
LogEvent.SyncStart.Log(DateTime.Now);
LogEvent.SyncError.Log("What the??? -- " + e.Message);
LogEvent.SyncStop.Log(DateTime.Now);
It says here that they can be bitwise combined: MSDN.
Have you tried initializeData="Information|ActivityTracing"?
I had the same question. I eventually tried just putting in the decimal value for the bitwise combination of the TraceEventType values I wanted. It worked. In my case I wanted Critical, Error, Information and Warn to go to one listener. I set the value to 1 | 2 | 8 | 4 = 15. I had another listener I wanted just Verbose going to so I set the value to 16. I then set the source's switch to 16 | 15 = 31.
example (snippet):
<filter type="System.Diagnostics.TextWriterTraceListener" initializeData="15"/>
<switches>
<add name="sourceSwitch" value="31"/>
</switches>
Thanks,
Nick
I am converting some code to use Microsoft tracing. What I'd like is to define all the listeners in one project and then use them from other assemblies, without having to explicitly load them there.
To clarify, this is what I'm doing now:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.diagnostics>
<trace autoflush="true">
<listeners>
<add name="myListener" type="ConsoleApplication4.LogListener, ConsoleApplication4"/>
<remove name="Default" />
</listeners>
</trace>
</system.diagnostics>
</configuration>
And in the C# code:
var b = Trace.Listeners;
TraceSource tr = new TraceSource("Blah", SourceLevels.All);
tr.Listeners.Add(b["myListener"]);
tr.TraceEvent(TraceEventType.Warning, 5, "Hello");
What I would like is for myListener to be automatically added to any new trace source I create without having to look it up the way I'm doing now. Is this possible?
Define the trace source along with its listeners in config:
<system.diagnostics>
<sources>
<source name="Blah" switchValue="Warning">
<listeners>
<add name="myListener" />
</listeners>
</source>
</sources>
<!-- Note these are in sharedListeners rather than trace -->
<sharedListeners>
<add name="myListener" ... />
</sharedListeners>
<!-- Autoflush still works as expected -->
<trace autoflush="true" />
</system.diagnostics>
Then construct the TraceSource in code the way you already are (its trace level will be overridden by the switchValue in config), don't add any listeners to it and log to it as normal.