diff --git a/commons/src/main/java/org/archive/io/GenerationFileHandler.java b/commons/src/main/java/org/archive/io/GenerationFileHandler.java
index 03e21ad5..21c3d12e 100644
--- a/commons/src/main/java/org/archive/io/GenerationFileHandler.java
+++ b/commons/src/main/java/org/archive/io/GenerationFileHandler.java
@@ -24,8 +24,10 @@ import java.io.IOException;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.logging.FileHandler;
+import java.util.logging.Formatter;
 import java.util.logging.LogRecord;
 
+import org.archive.crawler.io.Preformatter;
 import org.archive.util.FileUtils;
 
 
@@ -138,10 +140,19 @@ public class GenerationFileHandler extends FileHandler {
 
     @Override
     public void publish(LogRecord record) {
-        // preformat outside synchronized superclass method
-        // (our most involved UriProcessingFormatter will cache result for LogRecord)
-        getFormatter().format(record);
-        super.publish(record);
+        // when possible preformat outside synchronized superclass method
+        // (our most involved UriProcessingFormatter can cache result)
+        Formatter f = getFormatter(); 
+        if(!(f instanceof Preformatter)) {
+            super.publish(record);
+        } else {
+            try {
+                ((Preformatter)f).preformat(record); 
+                super.publish(record);
+            } finally {
+                ((Preformatter)f).clear();
+            }
+        }
     }
 //
 //    TODO: determine if there's another way to have this optimization without
diff --git a/engine/src/main/java/org/archive/crawler/io/Preformatter.java b/engine/src/main/java/org/archive/crawler/io/Preformatter.java
new file mode 100644
index 00000000..b0a3c596
--- /dev/null
+++ b/engine/src/main/java/org/archive/crawler/io/Preformatter.java
@@ -0,0 +1,32 @@
+/*
+ *  This file is part of the Heritrix web crawler (crawler.archive.org).
+ *
+ *  Licensed to the Internet Archive (IA) by one or more individual 
+ *  contributors. 
+ *
+ *  The IA licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.archive.crawler.io;
+
+import java.util.logging.LogRecord;
+
+/**
+ * Interface indicating a logging Formatter can preformat a record (outside
+ * the standard-implementation synchronized block) and cache it, returning it
+ * for the next request for formatting from the same thread. 
+ * @contributor gojomo
+ */
+public interface Preformatter {
+    public void preformat(LogRecord record); 
+    public void clear(); 
+}
diff --git a/engine/src/main/java/org/archive/crawler/io/UriProcessingFormatter.java b/engine/src/main/java/org/archive/crawler/io/UriProcessingFormatter.java
index 6be14cd4..fc0ac5d8 100644
--- a/engine/src/main/java/org/archive/crawler/io/UriProcessingFormatter.java
+++ b/engine/src/main/java/org/archive/crawler/io/UriProcessingFormatter.java
@@ -34,7 +34,7 @@ import org.archive.util.MimetypeUtils;
  * @author gojomo
  */
 public class UriProcessingFormatter
-extends Formatter implements CoreAttributeConstants {
+extends Formatter implements Preformatter, CoreAttributeConstants {
     private final static String NA = "-";
     /**
      * Guess at line length (URIs are assumed avg. of 128 bytes).
@@ -57,7 +57,6 @@ extends Formatter implements CoreAttributeConstants {
             }
     };
     
-    protected final ThreadLocal<LogRecord> cachedRecord = new ThreadLocal<LogRecord>(); 
     protected final ThreadLocal<String> cachedFormat = new ThreadLocal<String>();
     protected boolean logExtraInfo; 
     
@@ -66,7 +65,7 @@ extends Formatter implements CoreAttributeConstants {
     }
 
     public String format(LogRecord lr) {
-        if(lr==cachedRecord.get()) {
+        if(cachedFormat.get()!=null) {
             return cachedFormat.get();
         }
         CrawlURI curi = (CrawlURI)lr.getParameters()[0];
@@ -153,10 +152,7 @@ extends Formatter implements CoreAttributeConstants {
         }
         
         buffer.append("\n");
-        cachedRecord.set(lr); 
-        String formatted = buffer.toString(); 
-        cachedFormat.set(formatted);
-        return formatted;
+        return buffer.toString(); 
     }
 
     /**
@@ -166,6 +162,16 @@ extends Formatter implements CoreAttributeConstants {
     protected String checkForNull(String str) {
         return (str == null || str.length() <= 0)? NA: str;
     }
+
+    @Override
+    public void clear() {
+        cachedFormat.set(null); 
+    }
+
+    @Override
+    public void preformat(LogRecord record) {
+        cachedFormat.set(format(record));
+    }
 }
 
 
diff --git a/modules/src/main/java/org/archive/modules/CrawlURI.java b/modules/src/main/java/org/archive/modules/CrawlURI.java
index f8ded234..41a1d878 100644
--- a/modules/src/main/java/org/archive/modules/CrawlURI.java
+++ b/modules/src/main/java/org/archive/modules/CrawlURI.java
@@ -876,6 +876,12 @@ implements MultiReporter, Serializable, OverlayContext {
         this.linkExtractorFinished = false;
         // Clean the data map of all but registered permanent members.
         this.data = getPersistentDataMap();
+        
+        extraInfo = null;
+        overlayNames = null;
+        outCandidates = null;
+        outLinks = null;
+        method = null;
     }
     
     public Map<String,Object> getPersistentDataMap() {