configurazione log4j.xml con <rollingPolicy> e <triggeringPolicy>

Question

Provo a configurare log4j.xml in modo tale che il file venga spostato sulla dimensione del file e il nome del file arrotolato sarà: "C:/temp/test/test_log4j-% d {yyyy-MM-dd-hh_mm_ss} log" ho seguito questo dibattito: http://web.archiveorange.com/archive/v/NUYyjJipzkDOS3reRiMz

Infine ha funzionato per me solo quando aggiungo:

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

al metodo:

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

che lo fanno funzionare.

La domanda è se c'è un modo migliore per farlo funzionare? poiché questo metodo chiama molte volte e rallenta il mio programma.

Ecco il codice:

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; 
} 

} 

e la 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> 

Answer 1

Se si aggiunge l'output di debug al metodo, si vedrà che il metodo viene chiamato molto spesso, anche dopo che il trigger è già stato attivato, ma la dimensione del file è ancora in crescita superiore alla dimensione massima del file.

Presumo che il comportamento di rotazione abbia una sorta di buffer che viene svuotato prima che si verifichi il rollover effettivo (sincrono?).

Penso che abbia qualcosa a che fare con il fileNamePattern nello com.mypack.rolling.CustomTimeBasedRollingPolicy. Finché il 'secondo' nel nome del file non cambia, il metodo CustomSizeBasedTriggeringPolicy.isTriggeringEvent viene chiamato continuamente con quantità maggiori della dimensione massima del file.

Answer 2

Grazie per la risposta.

ho fatto 2 cambi:
1) Io aggiungo millisecondi per il modello di nome file:

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

2) ho cambiato

com.mypack.rolling.CustomSizeBasedTriggeringPolicy.isTriggeringEvent 

a

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; 
    } 

così ora , Thread.sleep (1) viene chiamato solo quando viene creato un nuovo file (rollato).