Develop Reference

Logback messages being appended to archive file

I have a Java Web application running on WLS 12 and using a logback RollingFileAppender to log data. Although it's inconsistent, I will occasionally see the current logging output being directed to one of the archive files created by the rollover process. For example, with the configuration below, I see current logging output being appended to debug.2019-01-17.0.txt instead of to main.log. Am I misunderstanding the expected behavior of the RollingFileAppender? If not, does anyone have an idea about what may be causing the behavior?
<appender name="ROLLING" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>${LOG-PATH}/main.log</file>
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<Pattern>[%d{yyyy-MM-dd HH:mm:ss}] [%5p] [%t] \(%F:%M:%L\) %m%n</Pattern>
</encoder>
<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
<fileNamePattern>${LOG-PATH}/debug.%d.%i.txt</fileNamePattern>
<maxFileSize>10MB</maxFileSize>
<maxHistory>45</maxHistory>
<totalSizeCap>1GB</totalSizeCap>
</rollingPolicy>
</appender>

Logback log to main file and clients in a separate directory

I have a Java server application for which I log all the general data to server.log and each individual client to its own hostname.log file. I want to put the hostname.log files in a different directory that server.log ideally in some organized fashion since there are thousands of hostname.log files.
This is the config I'm using now:
<appender name="SiftAppender" class="ch.qos.logback.classic.sift.SiftingAppender">
<discriminator>
<key>descriminatorid</key>
<defaultValue>server</defaultValue>
</discriminator>
<sift>
<appender name="FILE-${descriminatorid}" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>${cmb.log.dir}/${descriminatorid}.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<!-- daily rollover -->
<fileNamePattern>${cmb.log.dir}/archive/${descriminatorid}.%d{yyyy-MM-dd}.log.gz</fileNamePattern>
<!-- keep ${maxbackupindex} days' worth of history capped at ${maxfilesize} total size -->
<maxHistory>${cmb.log.maxbackupindex}</maxHistory>
<totalSizeCap>${cmb.log.maxfilesize}</totalSizeCap>
</rollingPolicy>
<encoder>
<pattern>%date{HH:mm:ss.SSS} [%thread] %-5level %msg%n</pattern>
</encoder>
</appender>
</sift>
</appender>
This config logs everything to $cmb.log.dir. What I'd like is something like this:
Server logs: $cmb.log.dir/server.log
Client logs: $cmb.log.dir/client/${descriminatorid}.log
Or even better would be:
Client logs: $cmb.log.dir/client/${firstLetter}/${descriminatorid}.log
where ${firstLetter} is the first letter of $descriminitorid. That way the logs would be distributed in a more scalable hierarchy.

The solution I found was very simple. Since I am generating ${descriminatorid} in my java code I simple included the directory structure i wanted in that value. So instead of "descriminatorid" being "hostname" it's now "client/firstletter/hostname".
I was definitely trying to overthink this one.

Logback not working with Prudent Mode is true

we are using below log file for logging data but we are not able to create file named as "mylogfile.log" which contains current date Logs .
however its creating Log file named as Logs "mylogfile2015.02.05.log for current day also as its not refering the tag defined.
Need help to create log file(mylogfile.log) without Date with Prudent mode is true to support multiple JVM's.
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>${MY_LOG_LOCATION_PROP}/logs/mylogfile.log</file>
<prudent>true</prudent>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<!-- rollover daily -->
<fileNamePattern>mylogfile-%d{yyyy-MM-dd}.%i.log</fileNamePattern>
</rollingPolicy>
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>

I guess you can't set file property of RollingFileAppender while using prudent mode.
Check this.

Logback RollingFileAppender not working in concurrent writing to same log?

We have a desktop application and recently introduce logback to the system.All the logs are going to the same place.And it's rolling nicely for single client.But if we run two client of the same application log file not rolling even after it's exceed its limit.If one client close rolling happens nicely.
<appender name="LOG-FILE"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>\log\log.txt</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<fileNamePattern>\log\old\log.%d{yyyyMMdd}_%i.txt</fileNamePattern>
<maxHistory>2</maxHistory>
<timeBasedFileNamingAndTriggeringPolicy
class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<maxFileSize>100KB</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
</rollingPolicy>
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>%d{yyyy.MM.dd HH:mm:ss} > [%thread] %-5level - %msg%n</Pattern>
</layout>

By default writing from multiple applications to the same file is supported (it might work for you, but you can see unexpected behavior when they both try to write at the same time).
You can solve this by enable prudent mode for your appender. This is done by setting prudent="true" as an attribute of your <appender> tag.
Note that for RollingFileAppender extra restrictions apply. For you this means you can not specify the 'file' property. Also you can not use the SizeAndTimeBasedFNATP but you have to change to a TimeBasedRollingPolicy.

RollingFileAppender that also deletes files older than some date

Do any of the popular Java logging frameworks support a rolling file appender, that I can configure to rollover daily, and also delete any log file that is over some number of days old? I know I could use a rolling file appender and a cron, but was wondering if anyone knew of an appender that can do both.

Logback's classic RollingFileAppender provides this and more. An example configuration from the manual (http://logback.qos.ch/manual/appenders.html#onRollingPolicies)
<configuration>
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>logFile.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<!-- daily rollover -->
<fileNamePattern>logFile.%d{yyyy-MM-dd}.log</fileNamePattern>
<!-- keep 30 days' worth of history -->
<maxHistory>30</maxHistory>
</rollingPolicy>
<encoder>
<pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
</encoder>
</appender>
<root level="DEBUG">
<appender-ref ref="FILE" />
</root>
</configuration>
This provides daily rollover and 30 days of history. Place this in a file called logback.xml, or logback-test.xml for test trees, and place it in the classpath.

After working a while on Log4j, I read that Logback was developed and designed to be the successor of Log4j, and I have to say, Logback is wide stepper!
For example, to configure, this rolling file Appender, and zip the older logs, and have a maximum of 30, on Log4J you have to perform some code changes (please review my previews answer for more details), but on logback, everything is done on the config file like this:
<configuration>
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>log/logFile.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<!-- daily rollover -->
<fileNamePattern>log/logFile.%d{yyyy-MM-dd}.log.zip</fileNamePattern>
<!-- keep 30 days' worth of history -->
<maxHistory>30</maxHistory>
</rollingPolicy>
<encoder>
<pattern>[%-5level]: [%logger{35}] - %msg%n</pattern>
</encoder>
</appender>
<root level="trace">
<appender-ref ref="FILE" />
</root>
</configuration>
And that's it, you will have the current log unzipped, and the older days, zip, one zip file by each day.
Wide more easier than log4j!
If you want to play with more config options, just check this link.

Indeed, if you are using Log4J you can use this appender:
http://blog.kimb3r.com/2008/07/improving-log4j-dailyrollingfileappende.html
It's very, very, VERY easy to use, just download the whole class(yes, the code of the class in the above link), include it in your project (wherever you want, you can change the package to match inside your project), and then configure the log4j.properties file like this(this file has to be in your classpath, for example in the src/main/resources folder):
# Define the root logger with appender file
log = log
log4j.rootLogger = TRACE, FILE
# Define the logical path where you put the class you downloaded from "blog.kimb3r.com" link (above)
log4j.appender.FILE=com.yourapp.yourpackage.log.CustodianDailyRollingFileAppender
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.conversionPattern=%m%n
log4j.appender.FILE.File=${log}/yourlogfile.log
log4j.appender.FILE.DatePattern='.'yyyy-MM-dd
# How many files you want to keep?, in this case I'm having just 15 days of files, one file per day:
log4j.appender.FILE.MaxNumberOfDays=15
# If True, the older files will be compressed into a zip file (*which will save you a lot of space on the server*)
log4j.appender.FILE.CompressBackups=true
and besides this just add the dependency to log4j into your pom like this:
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
And that's it!

Why not look at this might help?
You can probably set maximum nuber of days to retain the logs.
log4j.rootLogger=INFO, FILE
log4j.appender.FILE=ca.justtechnologies.utils.logging.CustodianDailyRollingFileAppender
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%d{MMM dd yyyy
HH:mm:ss,SSS} [%t] %-5p %l - %m%n
log4j.appender.FILE.File=/var/log/web-apps/Dashboard.log
log4j.appender.FILE.DatePattern='.'yyyy-MM-dd
log4j.appender.FILE.MaxNumberOfDays=14
log4j.appender.FILE.CompressBackups=true