Can log4j be configured to automatically indent messages with an amount proportional to the message log level? I need to get an output like this:
[2013-09-13 09:38:24,638] INFO - Processing graph nodes...
[2013-09-13 09:38:24,640] DEBUG - Processed node 1...
[2013-09-13 09:38:24,646] DEBUG - Processed node 2...
[2013-09-13 09:38:24,649] DEBUG - Processed node 3...
[2013-09-13 09:38:25,948] INFO - Processed 3 node(s)
I don't think you can do that by configuration. But you should be able to do it by implementing an custom Layout class that understands how to implement your indentation scheme. Then add that to your appender via the configuration file and all of your log messages will be formatted as you want them to be.
Not sure if log4j provides any such setting. But you can always write a wrapper method which takes the string message and the Log level as input and within it use a switch statement to do different intendation for different levels.
Below link is old but it is working. It extends Layout class but may be helpful to extend PatternLayout class on similar lines.
https://github.com/zepheira/tracer
Related
I am trying to eliminate a leading hyphen from our console and file logs in SpringBoot 1.3.5.RELEASE with default logback config.
Logging pattern looks like:
logging:
pattern:
console: '%d{yyyy-MM-dd HH:mm:ss.SSS} %clr([${spring.application.name}]){red} %clr(%5p) %clr(${PID:- }){magenta} %clr(---){faint} %X{req.requestId} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%rEx}'
The file log pattern is similar, without the color coding. Both output every line after the first with a leading hyphen, which is making our syslog - logstash - grok filtering trickier. Example output:
2016-06-21 11:52:00.576 [my-app] INFO etc.. (application started)
-2016-06-21 11:52:00.583 [my-app] DEBUG etc..
-2016-06-21 11:52:00.583 [my-app] INFO etc..
I can't see anything in the docs mentioning this behaviour. Welcome any advice on how to eliminate it, if possible!
Update
Thanks to Edgar's answer below, it turns out this was caused by the following at the end of our logging pattern:
${LOG_EXCEPTION_CONVERSION_WORD:-%rEx}
I replaced it with:
${LOG_EXCEPTION_CONVERSION_WORD:%rEx}
et voila, the hyphen at the start of the following line disappears. See http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-logging.html#boot-features-custom-log-configuration
The problem is in this part of logging.pattern.console:
${LOG_EXCEPTION_CONVERSION_WORD:-%rEx}
:- is Logback's default value delimiter and is what you should use in logback.xml. However, you're configuring things in application.properties where it's Spring Framework's default value delimiter (:) which should be used.
As you've used :-, you're saying use the value of LOG_EXCEPTION_CONVERSION_WORD and, if it's not set, use -%rEx instead.
The correct syntax is:
${LOG_EXCEPTION_CONVERSION_WORD:%rEx}
It's hard to diagnose without your providing the full logging format. I'm seeing something similar in our code, and it seems to be related to including this in the format:
${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}
If you're using it, then the hyphen may be the one before the %w. I'm not sure what the intended purpose of this is. If I find it, I'll add it to my answer.
I want to intercept logs from the specific thread in my application for the certain period of time. I'm using log4j.
The code below does that, but I'm getting logs from others threads too.
WriterAppender appender = new WriterAppender(new PatternLayout("%d{ISO8601} %p - %m%n"), consoleWriter);
appender.setName("STR_APPENDER");
appender.setThreshold(org.apache.log4j.Level.INFO);
Logger.getRootLogger().addAppender(appender);
//Some Logic here (I'm using other classes and jars here and I want to get this logs as well)
Logger.getRootLogger().removeAppender("STR_APPENDER");
I'm aware that Logger.getRootLogger() is not a good solution here, but I don't have any other idea.
You can use MDC.put.
eg
MDC.put("threadName",Thread.currentThread().getName());
Using that you can put thread name.
Using Log4j appender you can print the thread name [%X{threadName} in logs
I have a log4j logger that I instantiate like this:
logger = Logger.getLogger("EQUIP(" + id + ")");
Doing so, when I call logger.info("message"), I should get an output like this (with some date formatting):
13/11/12 15:08:27 INFO: EQUIP(1): message
But I'm only getting:
13/11/12 15:08:27 INFO: message
I'm also printing logger.getName() to the console for debugging and it gives me back the correct "EQUIP(1)" name. This behaviour is happening in some cases in my program, where I have several loggers like this, but mostly in this specific class. I want to know if I'm doing something wrong, if this name should be only the class/package name, or if it can be anything (it works well in 80+% of my loggers). I need to print the ID of each equipment because I have several of them working simultaneous, and tracking them without this would be next to impossible.
How should I fix this, preferably without resourcing to changing all my log calls to include this prefix?
The output format depends on the pattern you've configured for the appender. If the pattern string includes %c then you'll get the logger name included, if it doesn't then you won't.
An alternative approach might be to use the mapped diagnostic context, which is designed to disambiguate between log output from different threads writing to the same logger.
I'm trying to figure out why I'm generating multiple versions of my log files (.1, .2 ,etc). My project has a need for 3 separate loggers, I'm using java.util.log and setting up my loggers as follows:
logger = Logger.getLogger("Logger");
logger.addHandler(new FileHandler(logFileName));
statsLogger = Logger.getLogger("StatsLogger");
statsLogger.addHandler(new FileHandler(statsLogFileName));
alarmLogger = Logger.getLogger("AlarmLogger");
alarmLogger.addHandler(new FileHandler(alarmLogFileName));
my logging properties file:
handlers=java.util.logging.ConsoleHandler java.util.logging.FileHandler
java.util.logging.FileHandler.append=true
java.util.logging.FileHandler.level=INFO
java.util.logging.ConsoleHandler.level=INFO
java.util.logging.ConsoleHandler.formatter=com.package.LogFormatter
java.util.logging.FileHandler.formatter=com.package.LogFormatter
This seems to work, well as far as I can tell anyway... things seem to be getting logged to the correct log files. Any ideas on what could be causing this?
Thanks for any ideas
According to the FileHandler javadoc
http://docs.oracle.com/javase/1.4.2/docs/api/java/util/logging/FileHandler.html#FileHandler
Normally the "%u" unique field is set to 0. However, if the
FileHandler tries to open the filename and finds the file is currently
in use by another process it will increment the unique number field
and try again. This will be repeated until FileHandler finds a file
name that is not currently in use. If there is a conflict and no "%u"
field has been specified, it will be added at the end of the filename
after a dot. (This will be after any automatically added generation
number.)
Have you got multiple processes running that are using the same log configuration ? Also check that any old test processes are not showing up in windows process viewer or top.
What is the difference between logger.debug and logger.info ?
When will logger.debug be printed?
I suggest you look at the article called "Short Introduction to log4j". It contains a short explanation of log levels and demonstrates how they can be used in practice. The basic idea of log levels is that you want to be able to configure how much detail the logs contain depending on the situation. For example, if you are trying to troubleshoot an issue, you would want the logs to be very verbose. In production, you might only want to see warnings and errors.
The log level for each component of your system is usually controlled through a parameter in a configuration file, so it's easy to change. Your code would contain various logging statements with different levels. When responding to an Exception, you might call Logger.error. If you want to print the value of a variable at any given point, you might call Logger.debug. This combination of a configurable logging level and logging statements within your program allow you full control over how your application will log its activity.
In the case of log4j at least, the ordering of log levels is:
DEBUG < INFO < WARN < ERROR < FATAL
Here is a short example from that article demonstrating how log levels work.
// get a logger instance named "com.foo"
Logger logger = Logger.getLogger("com.foo");
// Now set its level. Normally you do not need to set the
// level of a logger programmatically. This is usually done
// in configuration files.
logger.setLevel(Level.INFO);
Logger barlogger = Logger.getLogger("com.foo.Bar");
// This request is enabled, because WARN >= INFO.
logger.warn("Low fuel level.");
// This request is disabled, because DEBUG < INFO.
logger.debug("Starting search for nearest gas station.");
// The logger instance barlogger, named "com.foo.Bar",
// will inherit its level from the logger named
// "com.foo" Thus, the following request is enabled
// because INFO >= INFO.
barlogger.info("Located nearest gas station.");
// This request is disabled, because DEBUG < INFO.
barlogger.debug("Exiting gas station search");
This will depend on the logging configuration. The default value will depend on the framework being used. The idea is that later on by changing a configuration setting from INFO to DEBUG you will see a ton of more (or less if the other way around) lines printed without recompiling the whole application.
If you think which one to use then it boils down to thinking what you want to see on which level. For other levels for example in Log4J look at the API, http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html
Just a clarification about the set of all possible levels, that are:
ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF
Basically it depends on how your loggers are configured. Typically you'd have debug output written out during development but turned off in production - or possibly have selected debug categories writing out while debugging a particular area.
The point of having different priorities is to allow you to turn up/down the level of detail on a particular component in a reasonably fine-grained way - and only needing to change the logging configuration (rather than code) to see the difference.
INFO is used to log the information your program is working as expected.
DEBUG is used to find the reason in case your program is not working as expected or an exception has occurred. it's in the interest of the developer.
This is a very old question, but i don't see my understanding here so I will add my 2 cents:
Every level corresponds/maps to a type of user:
debug : developer - manual debugging
trace : automated logging and step tracer - for 3rd level support
info : technician / support level 1 /2
warn : technician / user error : automated alert / support level 1
critical/fatal : depends on your setup - local IT
It depends on which level you selected in your log4j configuration file.
<Loggers>
<Root level="info">
...
If your level is "info" (by default), logger.debug(...) will not be printed in your console.
However, if your level is "debug", it will.
Depending on the criticality level of your code, you should use the most accurate level among the following ones :
ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF
Info Messages are something which we would like to see even if the application is in best of state.
Debug messages are usually something that we would like to see while debugging some problem.
What is the difference between logger.debug and logger.info?
These are only some default level already defined. You can define your own levels if you like.
The purpose of those levels is to enable/disable one or more of them, without making any change in your code.
When logger.debug will be printed ??
When you have enabled the debug or any higher level in your configuration.