diff --git a/core/src/main/scala/org/apache/spark/SparkEnv.scala b/core/src/main/scala/org/apache/spark/SparkEnv.scala
index 9b8384bcbb..29968c273c 100644
--- a/core/src/main/scala/org/apache/spark/SparkEnv.scala
+++ b/core/src/main/scala/org/apache/spark/SparkEnv.scala
@@ -156,7 +156,6 @@ object SparkEnv extends Logging {
 
     val serializer = serializerManager.setDefault(
       System.getProperty("spark.serializer", "org.apache.spark.serializer.JavaSerializer"))
-    logInfo("spark.serializer is " + System.getProperty("spark.serializer"))
 
     val closureSerializer = serializerManager.get(
       System.getProperty("spark.closure.serializer", "org.apache.spark.serializer.JavaSerializer"))
diff --git a/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
index 8a66297f6f..81bf867188 100644
--- a/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
@@ -245,7 +245,7 @@ class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
     if (getKeyClass().isArray && partitioner.isInstanceOf[HashPartitioner]) {
       throw new SparkException("Default partitioner cannot partition array keys.")
     }
-    new ShuffledRDD[K, V, (K, V)](self, partitioner) 
+    new ShuffledRDD[K, V, (K, V)](self, partitioner)
   }
 
   /**
@@ -265,9 +265,7 @@ class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
    * pair (k, (v, None)) if no elements in `other` have key k. Uses the given Partitioner to
    * partition the output RDD.
    */
-
-  def leftOuterJoin[W: ClassManifest](other: RDD[(K, W)], partitioner: Partitioner): 
-  RDD[(K, (V, Option[W]))] = {
+  def leftOuterJoin[W: ClassManifest](other: RDD[(K, W)], partitioner: Partitioner): RDD[(K, (V, Option[W]))] = {
     this.cogroup(other, partitioner).flatMapValues { case (vs, ws) =>
       if (ws.isEmpty) {
         vs.iterator.map(v => (v, None))
diff --git a/core/src/main/scala/org/apache/spark/serializer/KryoSerializer.scala b/core/src/main/scala/org/apache/spark/serializer/KryoSerializer.scala
index 263ff59ba6..55b25f145a 100644
--- a/core/src/main/scala/org/apache/spark/serializer/KryoSerializer.scala
+++ b/core/src/main/scala/org/apache/spark/serializer/KryoSerializer.scala
@@ -63,10 +63,14 @@ class KryoSerializer extends org.apache.spark.serializer.Serializer with Logging
     kryo.register(classOf[HttpBroadcast[_]], new KryoJavaSerializer())
 
     // Allow the user to register their own classes by setting spark.kryo.registrator
-    Option(System.getProperty("spark.kryo.registrator")).foreach { regCls =>
-      logDebug("Running user registrator: " + regCls)
-      val reg = Class.forName(regCls, true, classLoader).newInstance().asInstanceOf[KryoRegistrator]
-      reg.registerClasses(kryo)
+    try {
+      Option(System.getProperty("spark.kryo.registrator")).foreach { regCls =>
+        logDebug("Running user registrator: " + regCls)
+        val reg = Class.forName(regCls, true, classLoader).newInstance().asInstanceOf[KryoRegistrator]
+        reg.registerClasses(kryo)
+      }
+    } catch {
+      case _: Exception => println("Failed to register spark.kryo.registrator")
     }
 
     // Register Chill's classes; we do this after our ranges and the user's own classes to let
@@ -118,7 +122,7 @@ class KryoDeserializationStream(kryo: Kryo, inStream: InputStream) extends Deser
   }
 }
 
-private[spark] class KryoSerializerInstance(ks: KryoSerializer) extends SerializerInstance with Logging {
+private[spark] class KryoSerializerInstance(ks: KryoSerializer) extends SerializerInstance {
   val kryo = ks.newKryo()
 
   // Make these lazy vals to avoid creating a buffer unless we use them
diff --git a/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala b/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala
index 5082730ae3..2955986fec 100644
--- a/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala
+++ b/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala
@@ -25,7 +25,7 @@ import java.util.concurrent.ConcurrentHashMap
  * instance of the serializer object has been created, the get method returns that instead of
  * creating a new one.
  */
-private[spark] class SerializerManager extends org.apache.spark.Logging {
+private[spark] class SerializerManager {
 
   private val serializers = new ConcurrentHashMap[String, Serializer]
   private var _default: Serializer = _