Hi Alex, Thank you for the detailed description of the problem allowing its easy reproduction. It turns our that the configuration directives for ROLLING-FILE is lacking a crucial element, namely the "maxFileSize" property. This would have been evident if you had enabled logback's internal status messages with <configuration debug="true"> ... </configuration> or with the equivalent <configuration> <statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener" /> ... </configuration> I have modified the code of SizeAndTimeBasedFNATP to detect the missing the "maxFileSize" property sooner and immediately alert the user. Also note that more recent versions of logback ship with SizeAndTimeBasedRollingPolicy [1] which offers a more pleasant syntax than the TimeBasedRollingPolicy+SizeAndTimeBasedFNATP combination but with exactly the same functionality. Cheers, -- Ceki [1] http://logback.qos.ch/manual/appenders.html#SizeAndTimeBasedRollingPolicy On 5/5/2016 16:42, Alex Hall wrote:
Greetings, logback-users.
We recently switched from log4j to logback, and have observed some concerning behavior with RollingFileAppender - namely, it seems to be dropping log messages in what turns out to be a predictable manner. I'm including a simple test program that I wrote to illustrate the issue. Basically, the output of the test program indicates that the RollingFileAppender is dropping messages 16, 32, 64, 128, and so on.
Is this a known issue with RollingFileAppender? Is there some sort of error in our logback configuration? Any help is appreciated!
Regards, Alex Hall
==========
Operating system: Ubuntu 14.04 LTS Java version: Oracle JDK 1.8.0u72
Test program:
/lib: + logback-classic-1.1.7.jar + logback-core-1.1.7.jar + slf4j-api-1.7.21.jar
/resources/logback-test.xml: ---------- <configuration>
<appender name="FILE" class="ch.qos.logback.core.FileAppender"> <file>logs/test.log</file> <encoder> <pattern>%d [%thread] %-5level %logger{36} - %msg%n</pattern> </encoder> </appender>
<appender name="ROLLING-FILE" class="ch.qos.logback.core.rolling.RollingFileAppender"> <file>logs/rolling-test.log</file> <encoder> <pattern>%d [%thread] %-5level %logger{36} - %msg%n</pattern> </encoder> <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<fileNamePattern>logs/rolling-test-%d{yyyy-MM-dd}.%i.log</fileNamePattern> <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP" /> <maxHistory>30</maxHistory> <cleanHistoryOnStart>true</cleanHistoryOnStart> </rollingPolicy> </appender>
<root level="INFO"> <appender-ref ref="FILE" /> <appender-ref ref="ROLLING-FILE" /> </root>
</configuration> ----------
/src/RollingAppenderTest.java: ---------- import org.slf4j.Logger; import org.slf4j.LoggerFactory;
public class RollingAppenderTest { private static final Logger log = LoggerFactory.getLogger(RollingAppenderTest.class);
public static void main(String[] args) throws Exception { if (args.length != 1) { System.out.println("Usage: java RollingAppenderTest <num-messages>"); System.exit(1); }
int nMessages = Integer.parseInt(args[0]);
for (int i = 1; i <= nMessages; i++) { log.info <http://log.info>("Hello, " + i); } } } ----------
/run-test.sh ---------- #!/bin/sh
rm -rf logs rm -rf classes
echo "Compiling..." mkdir classes javac -cp 'lib/*' -d classes -sourcepath src src/*.java
echo "Running..." java -cp 'lib/*:classes:resources' RollingAppenderTest $1
echo "FileAppender output lines: $(wc -l logs/test.log)" echo "RollingFileAppender output lines: $(wc -l logs/rolling-test.log)" diff logs/test.log logs/rolling-test.log ----------
Test output: ---------- alex@alex-ubuntu14:~/src/scratch/logback-drops-messages$ ./run-test.sh 1000 Compiling... Running... FileAppender output lines: 1000 logs/test.log RollingFileAppender output lines: 994 logs/rolling-test.log 16d15 < 2016-05-05 14:40:14,365 [main] INFO RollingAppenderTest - Hello, 16 32d30 < 2016-05-05 14:40:14,366 [main] INFO RollingAppenderTest - Hello, 32 64d61 < 2016-05-05 14:40:14,380 [main] INFO RollingAppenderTest - Hello, 64 128d124 < 2016-05-05 14:40:14,383 [main] INFO RollingAppenderTest - Hello, 128 256d251 < 2016-05-05 14:40:14,405 [main] INFO RollingAppenderTest - Hello, 256 512d506 < 2016-05-05 14:40:14,439 [main] INFO RollingAppenderTest - Hello, 512 ----------
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