log4j 1.2.16 diff to show FileAppender been reset.

gistfile1.diff

diff --git a/build.xml b/build.xml
index e5ec33b..c05f24c 100644
--- a/build.xml
+++ b/build.xml
@@ -99,8 +99,8 @@
   <!-- Directory for temporary files. -->
   <property name="dist.tmp" value="${dist.dir}/tmp"/>
   
-  <property name="javac.source" value="1.2"/>
-  <property name="javac.target" value="1.1"/>
+  <property name="javac.source" value="1.5"/>
+  <property name="javac.target" value="1.5"/>
   
   <!--  destination for generated documentation on Apache web host  -->
   <property name="apache.javadoc_dest" value="/www/logging.apache.org/log4j/docs"/>
diff --git a/src/main/java/org/apache/log4j/FileAppender.java b/src/main/java/org/apache/log4j/FileAppender.java
index 0728695..de142aa 100644
--- a/src/main/java/org/apache/log4j/FileAppender.java
+++ b/src/main/java/org/apache/log4j/FileAppender.java
@@ -278,7 +278,7 @@ public class FileAppender extends WriterAppender {
   synchronized
   void setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)
                                                             throws IOException {
-    LogLog.debug("setFile called: "+fileName+", "+append);
+    LogLog.debug("setFile called for [" + name +"]: "+fileName+", "+append);
 
     // It does not make sense to have immediate flush and bufferedIO.
     if(bufferedIO) {
@@ -320,7 +320,7 @@ public class FileAppender extends WriterAppender {
     this.bufferedIO = bufferedIO;
     this.bufferSize = bufferSize;
     writeHeader();
-    LogLog.debug("setFile ended");
+    LogLog.debug("setFile ended for [" + name +"]: qw = [" + ((qw == null) ? "NULL" : qw.toString()) + "]");
   }
 
 
@@ -331,6 +331,7 @@ public class FileAppender extends WriterAppender {
    */
   protected
   void setQWForFiles(Writer writer) {
+     LogLog.debug("setQWForFiles called for [" + name + "]");
      this.qw = new QuietWriter(writer, errorHandler);
   }
 
diff --git a/src/main/java/org/apache/log4j/WriterAppender.java b/src/main/java/org/apache/log4j/WriterAppender.java
index 981c02d..d67873d 100644
--- a/src/main/java/org/apache/log4j/WriterAppender.java
+++ b/src/main/java/org/apache/log4j/WriterAppender.java
@@ -345,6 +345,11 @@ public class WriterAppender extends AppenderSkeleton {
   void reset() {
     closeWriter();
     this.qw = null;
+    LogLog.debug("Reset called for appender ["+name+"].");
+    StringBuilder sb = new StringBuilder();
+    for (StackTraceElement ste : Thread.currentThread().getStackTrace())
+        sb.append(ste.toString() + "\n");
+    LogLog.debug(sb.toString());
     //this.tp = null;
   }
 

Used to build a custom log4j 1.2.16 to use with Brisk. Logs to std out to show when a WriterAppender is reset and what was in the call stack.

Requires log4j.debug=true to be passed to the mapred task, make sure this is in the mapred-site.xml file

<property>
  <name>mapred.child.java.opts</name>
  <value>-Xmx256m -Dlog4j.debug=true</value>
  <description>
    Tune your mapred jvm arguments for best performance. 
    Also see documentation from jvm vendor.
  </description>
</property>