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Log4j.xml with <rollingPolicy> and <triggeringPolicy>

I am trying to configure log4j.xml so that the file will be scanned to fit the file and the name of the directory file will look like this: "C: / temp / test / test_log4j-% d {yyyy-MM-dd -HH_mm_ss} .log "I followed this discussion: http://web.archiveorange.com/archive/v/NUYyjJipzkDOS3reRiMz

Finally, this worked for me only when I add:

try { Thread.sleep(1); } catch (InterruptedException e) { e.printStackTrace(); }

to the method:

 public boolean isTriggeringEvent(Appender appender, LoggingEvent event, String filename, long fileLength)

which make it work.

The question is, is there a better way to make it work? since this method calls many times and slows down my program.

Here is the code:

 package com.mypack.rolling; import org.apache.log4j.rolling.RollingPolicy; import org.apache.log4j.rolling.RolloverDescription; import org.apache.log4j.rolling.TimeBasedRollingPolicy; /** * Same as org.apache.log4j.rolling.TimeBasedRollingPolicy but acts only as * RollingPolicy and NOT as TriggeringPolicy. * * This allows us to combine this class with a size-based triggering policy * (decision to roll based on size, name of rolled files based on time) * */ public class CustomTimeBasedRollingPolicy implements RollingPolicy { TimeBasedRollingPolicy timeBasedRollingPolicy = new TimeBasedRollingPolicy(); /** * Set file name pattern. * @param fnp file name pattern. */ public void setFileNamePattern(String fnp) { timeBasedRollingPolicy.setFileNamePattern(fnp); } /* public void setActiveFileName(String fnp) { timeBasedRollingPolicy.setActiveFileName(fnp); }*/ /** * Get file name pattern. * @return file name pattern. */ public String getFileNamePattern() { return timeBasedRollingPolicy.getFileNamePattern(); } public RolloverDescription initialize(String file, boolean append) throws SecurityException { return timeBasedRollingPolicy.initialize(file, append); } public RolloverDescription rollover(String activeFile) throws SecurityException { return timeBasedRollingPolicy.rollover(activeFile); } public void activateOptions() { timeBasedRollingPolicy.activateOptions(); } } package com.mypack.rolling; import org.apache.log4j.helpers.OptionConverter; import org.apache.log4j.Appender; import org.apache.log4j.rolling.TriggeringPolicy; import org.apache.log4j.spi.LoggingEvent; import org.apache.log4j.spi.OptionHandler; /** * Copy of org.apache.log4j.rolling.SizeBasedTriggeringPolicy but able to accept * a human-friendly value for maximumFileSize, eg. "10MB" * * Note that sub-classing SizeBasedTriggeringPolicy is not possible because that * class is final */ public class CustomSizeBasedTriggeringPolicy implements TriggeringPolicy, OptionHandler { /** * Rollover threshold size in bytes. */ private long maximumFileSize = 10 * 1024 * 1024; // let 10 MB the default max size /** * Set the maximum size that the output file is allowed to reach before * being rolled over to backup files. * * <p> * In configuration files, the <b>MaxFileSize</b> option takes an long * integer in the range 0 - 2^63. You can specify the value with the * suffixes "KB", "MB" or "GB" so that the integer is interpreted being * expressed respectively in kilobytes, megabytes or gigabytes. For example, * the value "10KB" will be interpreted as 10240. * * @param value * the maximum size that the output file is allowed to reach */ public void setMaxFileSize(String value) { maximumFileSize = OptionConverter.toFileSize(value, maximumFileSize + 1); } public long getMaximumFileSize() { return maximumFileSize; } public void setMaximumFileSize(long maximumFileSize) { this.maximumFileSize = maximumFileSize; } public void activateOptions() { } public boolean isTriggeringEvent(Appender appender, LoggingEvent event, String filename, long fileLength) { try { Thread.sleep(1); } catch (InterruptedException e) { e.printStackTrace(); } boolean result = (fileLength >= maximumFileSize); return result; } }

and log4j.xml:

 <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"> <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="true"> <appender name="console" class="org.apache.log4j.ConsoleAppender"> <param name="Target" value="System.out" /> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%d [%t] %-5p %c -> %m%n" /> </layout> </appender> <appender name="FILE" class="org.apache.log4j.rolling.RollingFileAppender"> <param name="file" value="C:/temp/test/test_log4j.log" /> <rollingPolicy class="com.mypack.rolling.CustomTimeBasedRollingPolicy"> <param name="fileNamePattern" value="C:/temp/test/test_log4j-%d{yyyy-MM-dd-HH_mm_ss}.log" /> </rollingPolicy> <triggeringPolicy class="com.mypack.rolling.CustomSizeBasedTriggeringPolicy"> <param name="MaxFileSize" value="200KB" /> </triggeringPolicy> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%d [%t] %-5p %c -> %m%n" /> </layout> </appender> <logger name="com.mypack.myrun" additivity="false"> <level value="debug" /> <appender-ref ref="FILE" /> </logger> <root> <priority value="debug" /> <appender-ref ref="console" /> </root> </log4j:configuration>
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2 answers

If you add debug output to this method, you will see that the method is called very often, even after the trigger is already running, but the file size still grows beyond the maximum file size.

I assume that the rolling behavior has some kind of buffer that is empty until the actual (synchronous?) Rollover.

I think this has something to do with the com.mypack.rolling.CustomTimeBasedRollingPolicy file in com.mypack.rolling.CustomTimeBasedRollingPolicy . As long as the “second” in the file name does not change, the CustomSizeBasedTriggeringPolicy.isTriggeringEvent method CustomSizeBasedTriggeringPolicy.isTriggeringEvent constantly called with amounts exceeding the maximum file size.

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Thanks for your reply.

I made 2 changes:
1) I add milliseconds to the file name pattern:

 <param name="fileNamePattern" value="C:/temp/test/test_log4j-%d{yyyy-MM-dd-HH_mm_ss_SSS}.log" />

2) I am Modified

 com.mypack.rolling.CustomSizeBasedTriggeringPolicy.isTriggeringEvent

to

 public boolean isTriggeringEvent(Appender appender, LoggingEvent event, String filename, long fileLength) { boolean result = (fileLength >= maximumFileSize); if (result) { try { Thread.sleep(1); } catch (InterruptedException e) { e.printStackTrace(); } } return result; }

so now Thread.sleep (1) is called only when a new file is created (shown).

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