使用NLog进行日志记录的最佳或最有用的配置是什么?(只要有用，这些可以简单也可以复杂。)
我正在考虑一些例子，比如自动滚动一定大小的日志文件，无论是否有异常，都会改变布局(日志消息)，一旦发生错误，就会升级日志级别，等等。
以下是一些链接:
NLog演示 源代码中的示例
当前回答
对于这个问题，我给出了几个相当有趣的答案:
日志文件的生成头部分
添加标题:
问题想知道如何向日志文件添加头文件。使用这样的配置条目允许您将头部格式与其余日志条目的格式分开定义。在应用程序开始时使用一个单独的日志记录器，可能称为“headerlogger”来记录单个消息，你就会得到你的头:
定义头文件和文件布局:
<variable name="HeaderLayout" value="This is the header. Start time = ${longdate} Machine = ${machinename} Product version = ${gdc:item=version}"/>
<variable name="FileLayout" value="${longdate} | ${logger} | ${level} | ${message}" />
使用布局定义目标:
<target name="fileHeader" xsi:type="File" fileName="xxx.log" layout="${HeaderLayout}" />
<target name="file" xsi:type="File" fileName="xxx.log" layout="${InfoLayout}" />
定义记录器:
<rules>
<logger name="headerlogger" minlevel="Trace" writeTo="fileHeader" final="true" />
<logger name="*" minlevel="Trace" writeTo="file" />
</rules>
写头文件，可能在程序的早期:
GlobalDiagnosticsContext.Set("version", "01.00.00.25");
LogManager.GetLogger("headerlogger").Info("It doesn't matter what this is because the header format does not include the message, although it could");
这在很大程度上只是“区别对待异常”思想的另一个版本。
用不同的布局记录每个日志级别
类似地，发布者想知道如何在每个日志级别更改格式。我不清楚最终目标是什么(以及是否可以以一种“更好”的方式实现)，但我能够提供一个符合他要求的配置:
<variable name="TraceLayout" value="This is a TRACE - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="DebugLayout" value="This is a DEBUG - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="InfoLayout" value="This is an INFO - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="WarnLayout" value="This is a WARN - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="ErrorLayout" value="This is an ERROR - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="FatalLayout" value="This is a FATAL - ${longdate} | ${logger} | ${level} | ${message}"/>
<targets>
<target name="fileAsTrace" xsi:type="FilteringWrapper" condition="level==LogLevel.Trace">
<target xsi:type="File" fileName="xxx.log" layout="${TraceLayout}" />
</target>
<target name="fileAsDebug" xsi:type="FilteringWrapper" condition="level==LogLevel.Debug">
<target xsi:type="File" fileName="xxx.log" layout="${DebugLayout}" />
</target>
<target name="fileAsInfo" xsi:type="FilteringWrapper" condition="level==LogLevel.Info">
<target xsi:type="File" fileName="xxx.log" layout="${InfoLayout}" />
</target>
<target name="fileAsWarn" xsi:type="FilteringWrapper" condition="level==LogLevel.Warn">
<target xsi:type="File" fileName="xxx.log" layout="${WarnLayout}" />
</target>
<target name="fileAsError" xsi:type="FilteringWrapper" condition="level==LogLevel.Error">
<target xsi:type="File" fileName="xxx.log" layout="${ErrorLayout}" />
</target>
<target name="fileAsFatal" xsi:type="FilteringWrapper" condition="level==LogLevel.Fatal">
<target xsi:type="File" fileName="xxx.log" layout="${FatalLayout}" />
</target>
</targets>
<rules>
<logger name="*" minlevel="Trace" writeTo="fileAsTrace,fileAsDebug,fileAsInfo,fileAsWarn,fileAsError,fileAsFatal" />
<logger name="*" minlevel="Info" writeTo="dbg" />
</rules>
同样，与区别对待异常非常相似。
其他回答
对于这个问题，我给出了几个相当有趣的答案:
日志文件的生成头部分
添加标题:
问题想知道如何向日志文件添加头文件。使用这样的配置条目允许您将头部格式与其余日志条目的格式分开定义。在应用程序开始时使用一个单独的日志记录器，可能称为“headerlogger”来记录单个消息，你就会得到你的头:
定义头文件和文件布局:
<variable name="HeaderLayout" value="This is the header. Start time = ${longdate} Machine = ${machinename} Product version = ${gdc:item=version}"/>
<variable name="FileLayout" value="${longdate} | ${logger} | ${level} | ${message}" />
使用布局定义目标:
<target name="fileHeader" xsi:type="File" fileName="xxx.log" layout="${HeaderLayout}" />
<target name="file" xsi:type="File" fileName="xxx.log" layout="${InfoLayout}" />
定义记录器:
<rules>
<logger name="headerlogger" minlevel="Trace" writeTo="fileHeader" final="true" />
<logger name="*" minlevel="Trace" writeTo="file" />
</rules>
写头文件，可能在程序的早期:
GlobalDiagnosticsContext.Set("version", "01.00.00.25");
LogManager.GetLogger("headerlogger").Info("It doesn't matter what this is because the header format does not include the message, although it could");
这在很大程度上只是“区别对待异常”思想的另一个版本。
用不同的布局记录每个日志级别
类似地，发布者想知道如何在每个日志级别更改格式。我不清楚最终目标是什么(以及是否可以以一种“更好”的方式实现)，但我能够提供一个符合他要求的配置:
<variable name="TraceLayout" value="This is a TRACE - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="DebugLayout" value="This is a DEBUG - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="InfoLayout" value="This is an INFO - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="WarnLayout" value="This is a WARN - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="ErrorLayout" value="This is an ERROR - ${longdate} | ${logger} | ${level} | ${message}"/>
<variable name="FatalLayout" value="This is a FATAL - ${longdate} | ${logger} | ${level} | ${message}"/>
<targets>
<target name="fileAsTrace" xsi:type="FilteringWrapper" condition="level==LogLevel.Trace">
<target xsi:type="File" fileName="xxx.log" layout="${TraceLayout}" />
</target>
<target name="fileAsDebug" xsi:type="FilteringWrapper" condition="level==LogLevel.Debug">
<target xsi:type="File" fileName="xxx.log" layout="${DebugLayout}" />
</target>
<target name="fileAsInfo" xsi:type="FilteringWrapper" condition="level==LogLevel.Info">
<target xsi:type="File" fileName="xxx.log" layout="${InfoLayout}" />
</target>
<target name="fileAsWarn" xsi:type="FilteringWrapper" condition="level==LogLevel.Warn">
<target xsi:type="File" fileName="xxx.log" layout="${WarnLayout}" />
</target>
<target name="fileAsError" xsi:type="FilteringWrapper" condition="level==LogLevel.Error">
<target xsi:type="File" fileName="xxx.log" layout="${ErrorLayout}" />
</target>
<target name="fileAsFatal" xsi:type="FilteringWrapper" condition="level==LogLevel.Fatal">
<target xsi:type="File" fileName="xxx.log" layout="${FatalLayout}" />
</target>
</targets>
<rules>
<logger name="*" minlevel="Trace" writeTo="fileAsTrace,fileAsDebug,fileAsInfo,fileAsWarn,fileAsError,fileAsFatal" />
<logger name="*" minlevel="Info" writeTo="dbg" />
</rules>
同样，与区别对待异常非常相似。
来自Silverlight的日志
当使用NLog和Silverlight一起使用时，你可以通过提供的web服务将跟踪发送到服务器端。你也可以写入隔离存储中的本地文件，如果web服务器不可用，这就派上用场了。请看这里的细节，也就是说，用一些类似的东西来让自己成为一个目标:
namespace NLogTargets
{
[Target("IsolatedStorageTarget")]
public sealed class IsolatedStorageTarget : TargetWithLayout
{
IsolatedStorageFile _storageFile = null;
string _fileName = "Nlog.log"; // Default. Configurable through the 'filename' attribute in nlog.config
public IsolatedStorageTarget()
{
}
~IsolatedStorageTarget()
{
if (_storageFile != null)
{
_storageFile.Dispose();
_storageFile = null;
}
}
public string filename
{
set
{
_fileName = value;
}
get
{
return _fileName;
}
}
protected override void Write(LogEventInfo logEvent)
{
try
{
writeToIsolatedStorage(this.Layout.Render(logEvent));
}
catch (Exception e)
{
// Not much to do about his....
}
}
public void writeToIsolatedStorage(string msg)
{
if (_storageFile == null)
_storageFile = IsolatedStorageFile.GetUserStoreForApplication();
using (IsolatedStorageFile isolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
// The isolated storage is limited in size. So, when approaching the limit
// simply purge the log file. (Yeah yeah, the file should be circular, I know...)
if (_storageFile.AvailableFreeSpace < msg.Length * 100)
{
using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(_fileName, FileMode.Truncate, FileAccess.Write, isolatedStorage))
{ }
}
// Write to isolated storage
using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(_fileName, FileMode.Append, FileAccess.Write, isolatedStorage))
{
using (TextWriter writer = new StreamWriter(stream))
{
writer.WriteLine(msg);
}
}
}
}
}
}
向外部网站/数据库报告
我想要一种简单而自动地报告应用程序错误的方法(因为用户通常不会这样做)。我能想到的最简单的解决方案是一个公共URL——一个可以接受输入并将其存储到数据库的网页——在应用程序出现错误时发送数据。(然后，开发人员或脚本可以检查数据库，以了解是否有新的错误。)
我用PHP编写了网页，并创建了mysql数据库、用户和表来存储数据。我决定使用四个用户变量、一个id和一个时间戳。可能的变量(包括在URL中或作为POST数据)是:
App(应用名称) msg(消息-例如，异常发生…) dev(开发人员，例如Pat) src (source -这将来自与应用程序正在运行的机器相关的变量，例如Environment。MachineName或其他类似的名称) 日志(日志文件或详细消息)
(所有的变量都是可选的，但是如果它们都没有设置，什么都不会报告-所以如果你只是访问网站URL，什么都不会发送到db。)
为了将数据发送到URL，我使用了NLog的WebService目标。(注意，一开始我在这个目标上遇到了一些问题。直到我看了源代码，我才发现我的url不能以/结尾。)
总而言之，对于监控外部应用程序来说，这是个不错的系统。(当然，礼貌的做法是通知您的用户您将报告可能敏感的数据，并给他们一个选择加入/退出的方法。)
MySQL的东西
(db用户在自己的数据库中对这个表只有INSERT权限。)
CREATE TABLE `reports` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`ts` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
`applicationName` text,
`message` text,
`developer` text,
`source` text,
`logData` longtext,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT='storage place for reports from external applications'
网站代码
(php5.3或5.2启用PDO，文件是index.php在/report文件夹)
<?php
$app = $_REQUEST['app'];
$msg = $_REQUEST['msg'];
$dev = $_REQUEST['dev'];
$src = $_REQUEST['src'];
$log = $_REQUEST['log'];
$dbData =
array( ':app' => $app,
':msg' => $msg,
':dev' => $dev,
':src' => $src,
':log' => $log
);
//print_r($dbData); // For debugging only! This could allow XSS attacks.
if(isEmpty($dbData)) die("No data provided");
try {
$db = new PDO("mysql:host=$host;dbname=reporting", "reporter", $pass, array(
PDO::ATTR_PERSISTENT => true
));
$s = $db->prepare("INSERT INTO reporting.reports
(
applicationName,
message,
developer,
source,
logData
)
VALUES
(
:app,
:msg,
:dev,
:src,
:log
);"
);
$s->execute($dbData);
print "Added report to database";
} catch (PDOException $e) {
// Sensitive information can be displayed if this exception isn't handled
//print "Error!: " . $e->getMessage() . "<br/>";
die("PDO error");
}
function isEmpty($array = array()) {
foreach ($array as $element) {
if (!empty($element)) {
return false;
}
}
return true;
}
?>
App代码(NLog配置文件)
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
throwExceptions="true" internalLogToConsole="true" internalLogLevel="Warn" internalLogFile="nlog.log">
<variable name="appTitle" value="My External App"/>
<variable name="csvPath" value="${specialfolder:folder=Desktop:file=${appTitle} log.csv}"/>
<variable name="developer" value="Pat"/>
<targets async="true">
<!--The following will keep the default number of log messages in a buffer and write out certain levels if there is an error and other levels if there is not. Messages that appeared before the error (in code) will be included, since they are buffered.-->
<wrapper-target xsi:type="BufferingWrapper" name="smartLog">
<wrapper-target xsi:type="PostFilteringWrapper">
<target xsi:type="File" fileName="${csvPath}"
archiveAboveSize="4194304" concurrentWrites="false" maxArchiveFiles="1" archiveNumbering="Sequence"
>
<layout xsi:type="CsvLayout" delimiter="Comma" withHeader="false">
<column name="time" layout="${longdate}" />
<column name="level" layout="${level:upperCase=true}"/>
<column name="message" layout="${message}" />
<column name="callsite" layout="${callsite:includeSourcePath=true}" />
<column name="stacktrace" layout="${stacktrace:topFrames=10}" />
<column name="exception" layout="${exception:format=ToString}"/>
<!--<column name="logger" layout="${logger}"/>-->
</layout>
</target>
<!--during normal execution only log certain messages-->
<defaultFilter>level >= LogLevel.Warn</defaultFilter>
<!--if there is at least one error, log everything from trace level-->
<when exists="level >= LogLevel.Error" filter="level >= LogLevel.Trace" />
</wrapper-target>
</wrapper-target>
<target xsi:type="WebService" name="web"
url="http://example.com/report"
methodName=""
namespace=""
protocol="HttpPost"
>
<parameter name="app" layout="${appTitle}"/>
<parameter name="msg" layout="${message}"/>
<parameter name="dev" layout="${developer}"/>
<parameter name="src" layout="${environment:variable=UserName} (${windows-identity}) on ${machinename} running os ${environment:variable=OSVersion} with CLR v${environment:variable=Version}"/>
<parameter name="log" layout="${file-contents:fileName=${csvPath}}"/>
</target>
</targets>
<rules>
<logger name="*" minlevel="Trace" writeTo="smartLog"/>
<logger name="*" minlevel="Error" writeTo="web"/>
</rules>
</nlog>
注意:日志文件的大小可能会有一些问题，但我还没有想出一个简单的方法来截断它(例如la *nix的tail命令)。
登录Twitter
Based on this post about a log4net Twitter Appender, I thought I would try my hand at writing a NLog Twitter Target (using NLog 1.0 refresh, not 2.0). Alas, so far I have not been able to get a Tweet to actually post successfully. I don't know if it is something wrong in my code, Twitter, our company's internet connection/firewall, or what. I am posting the code here in case someone is interested in trying it out. Note that there are three different "Post" methods. The first one that I tried is PostMessageToTwitter. PostMessageToTwitter is essentially the same as PostLoggingEvent in the orignal post. If I use that I get a 401 exception. PostMessageBasic gets the same exception. PostMessage runs with no errors, but the message still does not make it up to Twitter. PostMessage and PostMessageBasic are based on examples that I found here on SO.
仅供参考——我刚刚发现了@Jason Diller对这篇文章的一个回答的评论，他说twitter将在下个月关闭基本的身份验证。这是在2010年5月，现在是2010年12月，所以我想这可能就是为什么它不起作用的原因。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Web;
using System.IO;
using NLog;
using NLog.Targets;
using NLog.Config;
namespace NLogExtensions
{
[Target("TwitterTarget")]
public class TwitterTarget : TargetWithLayout
{
private const string REQUEST_CONTENT_TYPE = "application/x-www-form-urlencoded";
private const string REQUEST_METHOD = "POST";
// The source attribute has been removed from the Twitter API,
// unless you're using OAuth.
// Even if you are using OAuth, there's still an approval process.
// Not worth it; "API" will work for now!
// private const string TWITTER_SOURCE_NAME = "Log4Net";
private const string TWITTER_UPDATE_URL_FORMAT = "http://twitter.com/statuses/update.xml?status={0}";
[RequiredParameter]
public string TwitterUserName { get; set; }
[RequiredParameter]
public string TwitterPassword { get; set; }
protected override void Write(LogEventInfo logEvent)
{
if (string.IsNullOrWhiteSpace(TwitterUserName) || string.IsNullOrWhiteSpace(TwitterPassword)) return;
string msg = this.CompiledLayout.GetFormattedMessage(logEvent);
if (string.IsNullOrWhiteSpace(msg)) return;
try
{
//PostMessageToTwitter(msg);
PostMessageBasic(msg);
}
catch (Exception ex)
{
//Should probably do something here ...
}
}
private void PostMessageBasic(string msg)
{
// Create a webclient with the twitter account credentials, which will be used to set the HTTP header for basic authentication
WebClient client = new WebClient { Credentials = new NetworkCredential { UserName = TwitterUserName, Password = TwitterPassword } };
// Don't wait to receive a 100 Continue HTTP response from the server before sending out the message body
ServicePointManager.Expect100Continue = false;
// Construct the message body
byte[] messageBody = Encoding.ASCII.GetBytes("status=" + msg);
// Send the HTTP headers and message body (a.k.a. Post the data)
client.UploadData(@"http://twitter.com/statuses/update.xml", messageBody);
}
private void PostMessage(string msg)
{
string user = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(TwitterUserName + ":" + TwitterPassword));
byte [] bytes = System.Text.Encoding.UTF8.GetBytes("status=" + msg.ToTweet());
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://twitter.com/statuses/update.xml");
request.Method = "POST";
request.ServicePoint.Expect100Continue = false;
request.Headers.Add("Authorization", "Basic " + user);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = bytes.Length;
Stream reqStream = request.GetRequestStream();
reqStream.Write(bytes, 0, bytes.Length);
reqStream.Close();
}
private void PostMessageToTwitter(string msg)
{
var updateRequest = HttpWebRequest.Create(string.Format(TWITTER_UPDATE_URL_FORMAT,
HttpUtility.UrlEncode(msg.ToTweet()))) as HttpWebRequest;
updateRequest.ContentLength = 0;
updateRequest.ContentType = REQUEST_CONTENT_TYPE;
updateRequest.Credentials = new NetworkCredential(TwitterUserName, TwitterPassword);
updateRequest.Method = REQUEST_METHOD;
updateRequest.ServicePoint.Expect100Continue = false;
var updateResponse = updateRequest.GetResponse() as HttpWebResponse;
if (updateResponse.StatusCode != HttpStatusCode.OK && updateResponse.StatusCode != HttpStatusCode.Continue)
{
throw new Exception(string.Format("An error occurred while invoking the Twitter REST API [Response Code: {0}]", updateResponse.StatusCode));
}
}
}
public static class Extensions
{
public static string ToTweet(this string s)
{
if (string.IsNullOrEmpty(s) || s.Length < 140)
{
return s;
}
return s.Substring(0, 137) + "...";
}
}
}
这样配置:
告诉NLog包含目标的程序集:
<extensions>
<add assembly="NLogExtensions"/>
</extensions>
配置目标:
<targets>
<target name="twitter" type="TwitterTarget" TwitterUserName="yourtwittername" TwitterPassword="yourtwitterpassword" layout="${longdate} ${logger} ${level} ${message}" />
</targets>
如果有人尝试了这个方法并取得了成功，请将你的发现反馈给我们。
根据是否有错误记录不同的级别
此示例允许您在代码中出现错误时获取更多信息。基本上，它缓冲消息，只输出那些在一定的日志级别(例如警告)，除非满足一定的条件(例如，有一个错误，所以日志级别是>=错误)，然后它将输出更多的信息(例如，所有来自日志级别>= Trace的消息)。因为消息是缓冲的，这让您可以收集关于在Error或ErrorException被记录之前发生了什么的跟踪信息——非常有用!
I adapted this one from an example in the source code. I was thrown at first because I left out the AspNetBufferingWrapper (since mine isn't an ASP app) - it turns out that the PostFilteringWrapper requires some buffered target. Note that the target-ref element used in the above-linked example cannot be used in NLog 1.0 (I am using 1.0 Refresh for a .NET 4.0 app); it is necessary to put your target inside the wrapper block. Also note that the logic syntax (i.e. greater-than or less-than symbols, < and >) has to use the symbols, not the XML escapes for those symbols (i.e. > and <) or else NLog will error.
app.config:
<?xml version="1.0"?>
<configuration>
<configSections>
<section name="nlog" type="NLog.Config.ConfigSectionHandler, NLog"/>
</configSections>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
throwExceptions="true" internalLogToConsole="true" internalLogLevel="Warn" internalLogFile="nlog.log">
<variable name="appTitle" value="My app"/>
<variable name="csvPath" value="${specialfolder:folder=Desktop:file=${appTitle} log.csv}"/>
<targets async="true">
<!--The following will keep the default number of log messages in a buffer and write out certain levels if there is an error and other levels if there is not. Messages that appeared before the error (in code) will be included, since they are buffered.-->
<wrapper-target xsi:type="BufferingWrapper" name="smartLog">
<wrapper-target xsi:type="PostFilteringWrapper">
<!--<target-ref name="fileAsCsv"/>-->
<target xsi:type="File" fileName="${csvPath}"
archiveAboveSize="4194304" concurrentWrites="false" maxArchiveFiles="1" archiveNumbering="Sequence"
>
<layout xsi:type="CsvLayout" delimiter="Tab" withHeader="false">
<column name="time" layout="${longdate}" />
<column name="level" layout="${level:upperCase=true}"/>
<column name="message" layout="${message}" />
<column name="callsite" layout="${callsite:includeSourcePath=true}" />
<column name="stacktrace" layout="${stacktrace:topFrames=10}" />
<column name="exception" layout="${exception:format=ToString}"/>
<!--<column name="logger" layout="${logger}"/>-->
</layout>
</target>
<!--during normal execution only log certain messages-->
<defaultFilter>level >= LogLevel.Warn</defaultFilter>
<!--if there is at least one error, log everything from trace level-->
<when exists="level >= LogLevel.Error" filter="level >= LogLevel.Trace" />
</wrapper-target>
</wrapper-target>
</targets>
<rules>
<logger name="*" minlevel="Trace" writeTo="smartLog"/>
</rules>
</nlog>
</configuration>
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