I am trying to use log4net to log to a file with a variable name using log4net.Util.PatternString.
The appender configuration looks like this:
<appender name="file2" type="log4net.Appender.FileAppender">
<file type="log4net.Util.PatternString" value="c:\temp\MyLogFile_PID%processid.log" />
<appendToFile value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %level - %message%newline" />
</layout>
</appender>
With this configuration, the file is succesfully created with a name something like this:
MyLogFile_PID12345.log
I have succesfully used %processid, %random{8}, %env{SOME_ENV_VAR}, %property{MYPROPERTY} and %appsetting{someKey}.
But what I want is to insert a date, and no matter what I try, it seems that I cannot make it understand any of:
%date, %utcdate, %date{DATE}, %utcdate{DATE}, %date{ISO8601}, %date{ABSOLUTE}, %date{{HH:mm:ss}
or basically any form of date.
For example, what is wrong in:
<file type="log4net.Util.PatternString" value="c:\temp\MyLogFile_%date{ISO8601}.log" />
I have also tried to use a separate node for the conversion pattern configuration to no avail:
<file type="log4net.Util.PatternString">
<conversionPattern value="c:\temp\MyLogFile_%date{ISO8601}.log" />
</file>
Right now I am using a custom property (with %property{MY_CUSTOM_PROPERTY_WITH_THE_NAME_I_WANT}) to achieve a similar effect, but apart from being somewhat overkill, I wonder what I am doing wrong. I have tried in different computers and different applications and I cannot get what I intend.
By the way, my real aim is to use it in RollingFileAppender, but I am asking (and trying) here about FileAppender just for simplicity sake.
Any help?
I see you're using the type log4net.Util.PatternString directly instead of the appender log4net.Appender.FileAppender, any specific reason for that?
I'm just looking at the examples from https://logging.apache.org/log4net/release/config-examples.html
I finally got it!
It seems the only way it works is specifying a date format string, and with NO ':' in it.
Despite the examples in https://logging.apache.org/log4net/release/sdk/index.html, where it uses %date{HH:mm:ss,fff}, %date{dd MMM yyyy HH:mm:ss,fff}, %date{ISO8601}, %date{ABSOLUTE} none of them seem to work!
But this (and similar ones) finally do:
<file type="log4net.Util.PatternString" value="c:\temp\MyLogFile_%date{yyyy-MM-dd_HH-mm-ss}.log" />
I am still scratching my head if I was doing something wrong or the documentation is just plain confusing.
I think it has to do with the fact that the character ':' is allowed in Linux filenames, but not on Windows (I am using Windows, as 90+% of log4net users, I guess). And ISO8601 and ABSOLUTE don´t work either probably because in both cases log4net translates them to a string with ':' in it, failing for the same reasons.
If this is true, being a logger for .NET, a framework that is overwhelmingly used in Windows systems, I think this is something they should have in mind.
Problem solved (albeit with some doubts).
Related
I am trying to clean up the logging configuration one of our applications currently uses for it's log4net implementation. The application is called with an argument containing the filepath to an XML file. That XML file includes various configuration information, one of which is the logger name to use.
Currently, every configuration file has it's own logger, and every logger has their own appenders. As an example we would have:
logger job1
logger job2
logger job3
and
appender consoleJob1
appender consoleJob2
appender consoleJob3
appender rollingFileJob1
appender rollingFileJob2
appender rollingFileJob3
appender smtpJob1
appender smtpJob2
appender smtpJob3
Even though each of those appenders have nearly identical configurations. With hundreds of configuration files, this logging configuration section of the app.config is quite large. I believe I can consolidate most of these down to just a handful of generic appenders (Console, rollingFile, smtpToIT, smptpToSupport etc), and change each logger to use the generic appenders.
A big roadblock to how I visualize this working, is that each appender would need to use the logger's name in the configuration somewhere. Is there a variable or setting I can use in an appender that will allow the appender to use the logger's name? For instance, the RollingFileAppender should log to '\log[loggername].txt' The smtpAppender should have a subject of 'Log for [loggername] on MM\DD\YYYY'.
I took a look at http://logging.apache.org/log4net/release/config-examples.html, and believe I understand how the date can be added but I don't see anything about accessing the logger name from within the appender.
Is there anyway to access a property of the logger being used within the appender? Further, am I understanding how log4net is meant to be configured, with appenders being re-used among multiple loggers? I hadn't heard of log4net until a few weeks ago so I might be going about this all wrong.
I found the solution elsewhere, in an answer to a different question. Unfortunately I don't remember where I found it and only came back to my original question because of Newtopian's answer.
You can set a Global property through the following line:
log4net.GlobalContext.Properties["id"] = "SomeText";
Then refer to it in the appender as I did below:
<appender name="NewAuto2ProcessingTestFILE" type="log4net.Appender.RollingFileAppender">
<file type="log4net.Util.PatternString" value="Log/%property{id}NewAuto2ProcessingTest.txt" />
<appendToFile value="true" />
<maxSizeRollBackups value="10" />
<staticLogFileName value="true" />
<datePattern value=".yyyy-MM-dd.\\t\\x\\t" />
<rollingStyle value="Date" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d [%t] %-5p - %m%n" />
</layout>
</appender>
Was looking for the same thing, unfortunately it seems it's not possible out of the box, check the doc here about the accepted variables in the pattern String.
You'd probably would have to create your own appender, or your own formatter, to gain access to more variables (I suspect both).
I have a WCF service running on a single server, using Log4net to track usage via INFO and WARN level log entries. Using a RollingFileAppender with the following very standard config:
<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="\\mylocation\data\PRD\myApp\MyService"/>
<appendToFile value="true" />
<rollingStyle value="Date" />
<datePattern value="-yyyy-MM-dd'.log'" />
<staticLogFileName value="false" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
</layout>
</appender>
<root>
<level value="ALL" />
<appender-ref ref="RollingLogFileAppender" />
<appender-ref ref="ADONetAppender_SqlServer" />
</root>
I also use an ADONetAppender, which receives redirected "WARN" level data and writes it to a DB table in SQL server via a stored procedure. The config for this is a bit long, so I have omitted it for readability.
I have this setup in our Dev and TST environments where it has been running fine. In the PRD environment, it seems to generate duplicate log files. The first is named according to my specified pattern i.e. "logfile-yyyy-mm-dd.log". The second file looks like an addition to the first, with the date pattern duplicated i.e. "logfile-yyyy-mm-dd.log.-yyyy-mm-dd.log".
Making this more interesting is that entries contained in the two files overlap by time. File 1 might have entries from 8am to 12am, and file 2 will also contain entries from the same time period. The entries are not duplicates, they are generated by different users of the service. The copies of Files 1 and 2 can be pretty much any size, so this is not an issue of reaching a size or date/time threshold and generating the next required log file.
The DB table entries contain all the expected rows, some contained in each of the log files. These rows are generated only by WARN level logging, and some WARNings appear in each log file.
I have bounced this off some log4net savvy folks in our shop, but nobody has a good idea of what might be causing this duplicate file behavior. Any ideas from Stackland appreciated.
Your date pattern shouldn't have .log after it. I also am unsure why you have two appenders declared in the root. You should be able to get rid of the root altogether, given the rest of your config it has no purpose (assuming you don't have more that isn't in the example).
I've found that this happens when the file being logged to is locked by another thread or process.
I'm assuming Log4Net creates the other file because it can't log to the configured logfile and thus creates a new file and logs to it, but I'd have to go through the log4net code to be sure of that assumption.
Try adding
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
to the appender element to minimize the amount of locking. Just be aware that there is additional overhead associated with using MinimalLock: http://logging.apache.org/log4net/release/sdk/log4net.Appender.FileAppender.MinimalLock.html
I had the same exact problem.
I confirm that was a permission issue. In my case the logfiles were generated by two different accounts (from a scheduled task and sometimes by a manual run via console), and in this case the file name had a duplicate date pattern.
After resetting the permissions to both users (the scheduled process user and the interactive users) the issue did not repeat anymore.
Greets,
Michele
I've got this settings for log4net in the log4net.config to allow multiple threads to write to the same file:
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
<!-- Minimal locking to allow multiple threads to write to the same file -->
<lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
<file value="log\UI.log"/>
<appendToFile value="true"/>
<rollingStyle value="Date"/>
<maxSizeRollBackups value="30"/>
<datePattern value="-yyyyMMdd"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%newline%date [%thread] %-5level [%property{identity}] %logger{3} - %message%newline"/>
</layout>
</appender>
But after midnight the new created log file is being overwritten all the time and thus there is only the last one event in the file. After server restart it all goes right again till the next midnight.
So can anyone say whether this is a config issue or this is just a log4net issue?
The problem was solved by removing the locking model key since I have only one process (IIS, w3wp.exe) which uses the same logger.
<lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
Since it was said here:
If you use RollingFileAppender things become even worse as several process may try to start rolling the log file concurrently. RollingFileAppender completely ignores the locking model when rolling files, rolling files is simply not compatible with this scenario.
I think you will get unpredictable results.
My guess is that your use of a - sign on the datePattern is confusing the framework so that after the first roll any log triggers a roll event.
What happens when you try this with
<datePattern value="yyyyMMdd" />
per the example here.
To change the rolling period adjust the DatePattern value. For
example, a date pattern of "yyyyMMdd" will roll every day. See
System.Globalization.DateTimeFormatInfo for a list of available
patterns.
There are several posts on the internet for the same topic and I am also able to write multiple log files from my Windows Forms App. But my requirement is slightly different.
My app has two modes of running, say like "BuySomething" mode & "SellSomeOtherThing" mode. And when it is in "BuySomething" mode I want to write to Log_BuySomething.txt and to Log_SellSomeOtherThing.txt otherwise (one mode will be selected for sure).
In the app.config file, I have the same structure as in the last post of a StackOverflow Question.
My problem is that, when the code XmlConfigurator.Configure(); is executed, it creates empty log files of the names mentioned in both LogFileAppenders in the app.config file. I thought the following code would solve it, but it didn't:
if (mode == BuySomeThing)
{
logger = LogManager.GetLogger("LogFileAppender1");
}
else
{
LogManager.GetLogger("LogFileAppender2");
}
XmlConfigurator.Configure();
How can I make sure that only the appropriate log file is created for that instance of the App?
If I understand you, your app doesn't switch between modes.
If so, then I would suspect that using your code will create both files, but only actually write to one.
If getting rid of the zero-byte file is important you could try something like:
log4net.GlobalContext.Properties["MyLogFileName"] =
(mode == BuySomeThing) ? "Log_BuySomething.txt" : "Log_SellSomeOtherThing.txt" ;
XmlConfigurator.Configure();
You also need to change your config file to only have one appender and tell it to use this property for the file name, e.g.
<appender name="FileAppender" type="log4net.Appender.FileAppender">
<file type="log4net.Util.PatternString" value="Logfiles\%property{MyLogFileName}" />
<appendToFile value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
This should end up creating just one file. (In this example it will be created in the folder logfiles).
According to the Log4Net documentation, the RollingFileAppender will only roll the log file when a message is logged. I need to log to this file, but import it every day into another database. I cannot use a database appender because I need the files and I have to translate the data from the log file to the database (it isn't a direct copy). The problem is if there is no log activity after midnight, the log doesn't roll. The importer looks for the previous days file (and I can't change this code), so if there is no activity and the log hasn't rolled, the importer doesn't find the file. Is there anyway to force the log to roll at midnight without having another thread that wakes up and forces it to roll? Could a custom appender do this? I would like to avoid this if possible.
Write a Windows Service that fires an event just after midnight that writes a dummy log entry using the same configuration.
You have to think about this from the point of the question "what code paths lead to the rollover routine?". Once you know how that routine is reached you can decide how to trigger it.
Could a custom appender do it? Sure, but no code in the appender will run until you log via it so you're back to square one.
As for the question "Is there anyway to force the log to roll at midnight without having another thread that wakes up and forces it to roll?", I would say that that question is equivalent to "Is it possible to force the log to roll at midnight without any code being run?". I'm not trying to be funny about it, or to insult you, I'm just trying to restate the question in a way which will hopefully answer it for you. :-)
The easiest way to solve this is to have something wake up and log to force the file to rotate.
According to the RollingFileAppender documentation you can set it to roll on a daily basis, see this configuration:
<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="logfile" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<datePattern value="yyyyMMdd" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>