Index: conf/nutch-default.xml
===================================================================
--- conf/nutch-default.xml	(revision 1445485)
+++ conf/nutch-default.xml	(working copy)
@@ -1185,6 +1185,14 @@
   </description>
 </property>
 
+<property>
+  <name>urlfilter.max_url_length</name>
+  <value>300</value>
+  <description>Some urls like base64 image generators take long time to filtering.
+    url length limitation ignores urls like this.
+  </description>
+</property>
+
 <!-- scoring filters properties -->
 
 <property>
Index: src/plugin/lib-regex-filter/src/java/org/apache/nutch/urlfilter/api/RegexURLFilterBase.java
===================================================================
--- src/plugin/lib-regex-filter/src/java/org/apache/nutch/urlfilter/api/RegexURLFilterBase.java	(revision 1445485)
+++ src/plugin/lib-regex-filter/src/java/org/apache/nutch/urlfilter/api/RegexURLFilterBase.java	(working copy)
@@ -66,7 +66,8 @@
   /** The current configuration */
   private Configuration conf;
 
-
+  private int MAX_URL_LENGTH = 300; 
+    
   /**
    * Constructs a new empty RegexURLFilterBase
    */
@@ -127,7 +128,7 @@
   // Inherited Javadoc
   public String filter(String url) {
     for (RegexRule rule : rules) {
-      if (rule.match(url)) {
+      if (url.length() < MAX_URL_LENGTH && rule.match(url)) {
         return rule.accept() ? url : null;
       }
     };
@@ -144,7 +145,11 @@
    * ----------------------------- */
   
   public void setConf(Configuration conf) {
+
     this.conf = conf;
+      
+    MAX_URL_LENGTH = conf.getInt("urlfilter.max_url_length", 300);
+     
     Reader reader = null;
     try {
       reader = getRulesReader(conf);