[SPARK-17332][CORE] Make Java Loggers static members

## What changes were proposed in this pull request?

Make all Java Loggers static members

## How was this patch tested?

Jenkins

Author: Sean Owen <sowen@cloudera.com>

Closes #14896 from srowen/SPARK-17332.

common/network-common/src/main/java/org/apache/spark/network/TransportContext.java

@@ -56,7 +56,7 @@ import org.apache.spark.network.util.TransportFrameDecoder;
  * processes to send messages back to the client on an existing channel.
  */
 public class TransportContext {
-  private final Logger logger = LoggerFactory.getLogger(TransportContext.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportContext.class);
 
   private final TransportConf conf;
   private final RpcHandler rpcHandler;

common/network-common/src/main/java/org/apache/spark/network/client/TransportClient.java

@@ -72,7 +72,7 @@ import static org.apache.spark.network.util.NettyUtils.getRemoteAddress;
  * Concurrency: thread safe and can be called from multiple threads.
  */
 public class TransportClient implements Closeable {
-  private final Logger logger = LoggerFactory.getLogger(TransportClient.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportClient.class);
 
   private final Channel channel;
   private final TransportResponseHandler handler;

common/network-common/src/main/java/org/apache/spark/network/client/TransportClientFactory.java

@@ -73,7 +73,7 @@ public class TransportClientFactory implements Closeable {
     }
   }
 
-  private final Logger logger = LoggerFactory.getLogger(TransportClientFactory.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportClientFactory.class);
 
   private final TransportContext context;
   private final TransportConf conf;

common/network-common/src/main/java/org/apache/spark/network/client/TransportResponseHandler.java

@@ -48,7 +48,7 @@ import org.apache.spark.network.util.TransportFrameDecoder;
  * Concurrency: thread safe and can be called from multiple threads.
  */
 public class TransportResponseHandler extends MessageHandler<ResponseMessage> {
-  private final Logger logger = LoggerFactory.getLogger(TransportResponseHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportResponseHandler.class);
 
   private final Channel channel;
 

common/network-common/src/main/java/org/apache/spark/network/protocol/MessageDecoder.java

@@ -33,7 +33,8 @@ import org.slf4j.LoggerFactory;
 @ChannelHandler.Sharable
 public final class MessageDecoder extends MessageToMessageDecoder<ByteBuf> {
 
-  private final Logger logger = LoggerFactory.getLogger(MessageDecoder.class);
+  private static final Logger logger = LoggerFactory.getLogger(MessageDecoder.class);
+
   @Override
   public void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
     Message.Type msgType = Message.Type.decode(in);

common/network-common/src/main/java/org/apache/spark/network/protocol/MessageEncoder.java

@@ -33,7 +33,7 @@ import org.slf4j.LoggerFactory;
 @ChannelHandler.Sharable
 public final class MessageEncoder extends MessageToMessageEncoder<Message> {
 
-  private final Logger logger = LoggerFactory.getLogger(MessageEncoder.class);
+  private static final Logger logger = LoggerFactory.getLogger(MessageEncoder.class);
 
   /***
    * Encodes a Message by invoking its encode() method. For non-data messages, we will add one

common/network-common/src/main/java/org/apache/spark/network/sasl/SaslClientBootstrap.java

@@ -38,7 +38,7 @@ import org.apache.spark.network.util.TransportConf;
  * server should be setup with a {@link SaslRpcHandler} with matching keys for the given appId.
  */
 public class SaslClientBootstrap implements TransportClientBootstrap {
-  private final Logger logger = LoggerFactory.getLogger(SaslClientBootstrap.class);
+  private static final Logger logger = LoggerFactory.getLogger(SaslClientBootstrap.class);
 
   private final boolean encrypt;
   private final TransportConf conf;

common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslClient.java

@@ -43,7 +43,7 @@ import static org.apache.spark.network.sasl.SparkSaslServer.*;
  * firstToken, which is then followed by a set of challenges and responses.
  */
 public class SparkSaslClient implements SaslEncryptionBackend {
-  private final Logger logger = LoggerFactory.getLogger(SparkSaslClient.class);
+  private static final Logger logger = LoggerFactory.getLogger(SparkSaslClient.class);
 
   private final String secretKeyId;
   private final SecretKeyHolder secretKeyHolder;

common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslServer.java

@@ -45,7 +45,7 @@ import org.slf4j.LoggerFactory;
  * connections on some socket.)
  */
 public class SparkSaslServer implements SaslEncryptionBackend {
-  private final Logger logger = LoggerFactory.getLogger(SparkSaslServer.class);
+  private static final Logger logger = LoggerFactory.getLogger(SparkSaslServer.class);
 
   /**
    * This is passed as the server name when creating the sasl client/server.

common/network-common/src/main/java/org/apache/spark/network/server/OneForOneStreamManager.java

@@ -36,7 +36,7 @@ import org.apache.spark.network.client.TransportClient;
  * individually fetched as chunks by the client. Each registered buffer is one chunk.
  */
 public class OneForOneStreamManager extends StreamManager {
-  private final Logger logger = LoggerFactory.getLogger(OneForOneStreamManager.class);
+  private static final Logger logger = LoggerFactory.getLogger(OneForOneStreamManager.class);
 
   private final AtomicLong nextStreamId;
   private final ConcurrentHashMap<Long, StreamState> streams;

common/network-common/src/main/java/org/apache/spark/network/server/RpcHandler.java

@@ -83,7 +83,7 @@ public abstract class RpcHandler {
 
   private static class OneWayRpcCallback implements RpcResponseCallback {
 
-    private final Logger logger = LoggerFactory.getLogger(OneWayRpcCallback.class);
+    private static final Logger logger = LoggerFactory.getLogger(OneWayRpcCallback.class);
 
     @Override
     public void onSuccess(ByteBuffer response) {

common/network-common/src/main/java/org/apache/spark/network/server/TransportChannelHandler.java

@@ -49,7 +49,7 @@ import static org.apache.spark.network.util.NettyUtils.getRemoteAddress;
  * timeout if the client is continuously sending but getting no responses, for simplicity.
  */
 public class TransportChannelHandler extends SimpleChannelInboundHandler<Message> {
-  private final Logger logger = LoggerFactory.getLogger(TransportChannelHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportChannelHandler.class);
 
   private final TransportClient client;
   private final TransportResponseHandler responseHandler;

common/network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java

@@ -53,7 +53,7 @@ import static org.apache.spark.network.util.NettyUtils.getRemoteAddress;
  * The messages should have been processed by the pipeline setup by {@link TransportServer}.
  */
 public class TransportRequestHandler extends MessageHandler<RequestMessage> {
-  private final Logger logger = LoggerFactory.getLogger(TransportRequestHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportRequestHandler.class);
 
   /** The Netty channel that this handler is associated with. */
   private final Channel channel;

common/network-common/src/main/java/org/apache/spark/network/server/TransportServer.java

@@ -44,7 +44,7 @@ import org.apache.spark.network.util.TransportConf;
  * Server for the efficient, low-level streaming service.
  */
 public class TransportServer implements Closeable {
-  private final Logger logger = LoggerFactory.getLogger(TransportServer.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportServer.class);
 
   private final TransportContext context;
   private final TransportConf conf;

common/network-shuffle/src/main/java/org/apache/spark/network/sasl/ShuffleSecretManager.java

@@ -29,7 +29,8 @@ import org.apache.spark.network.util.JavaUtils;
  * A class that manages shuffle secret used by the external shuffle service.
  */
 public class ShuffleSecretManager implements SecretKeyHolder {
-  private final Logger logger = LoggerFactory.getLogger(ShuffleSecretManager.class);
+  private static final Logger logger = LoggerFactory.getLogger(ShuffleSecretManager.class);
+
   private final ConcurrentHashMap<String, String> shuffleSecretMap;
 
   // Spark user used for authenticating SASL connections

common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockHandler.java

@@ -54,7 +54,7 @@ import org.apache.spark.network.util.TransportConf;
  * level shuffle block.
  */
 public class ExternalShuffleBlockHandler extends RpcHandler {
-  private final Logger logger = LoggerFactory.getLogger(ExternalShuffleBlockHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(ExternalShuffleBlockHandler.class);
 
   @VisibleForTesting
   final ExternalShuffleBlockResolver blockManager;

common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleClient.java

@@ -44,7 +44,7 @@ import org.apache.spark.network.util.TransportConf;
  * executors.
  */
 public class ExternalShuffleClient extends ShuffleClient {
-  private final Logger logger = LoggerFactory.getLogger(ExternalShuffleClient.class);
+  private static final Logger logger = LoggerFactory.getLogger(ExternalShuffleClient.class);
 
   private final TransportConf conf;
   private final boolean saslEnabled;

common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/OneForOneBlockFetcher.java

@@ -41,7 +41,7 @@ import org.apache.spark.network.shuffle.protocol.StreamHandle;
  * {@link org.apache.spark.network.server.OneForOneStreamManager} on the server side.
  */
 public class OneForOneBlockFetcher {
-  private final Logger logger = LoggerFactory.getLogger(OneForOneBlockFetcher.class);
+  private static final Logger logger = LoggerFactory.getLogger(OneForOneBlockFetcher.class);
 
   private final TransportClient client;
   private final OpenBlocks openMessage;

common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/RetryingBlockFetcher.java

@@ -64,7 +64,7 @@ public class RetryingBlockFetcher {
   private static final ExecutorService executorService = Executors.newCachedThreadPool(
     NettyUtils.createThreadFactory("Block Fetch Retry"));
 
-  private final Logger logger = LoggerFactory.getLogger(RetryingBlockFetcher.class);
+  private static final Logger logger = LoggerFactory.getLogger(RetryingBlockFetcher.class);
 
   /** Used to initiate new Block Fetches on our remaining blocks. */
   private final BlockFetchStarter fetchStarter;

common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/mesos/MesosExternalShuffleClient.java

@@ -44,7 +44,7 @@ import org.apache.spark.network.util.TransportConf;
  * has to detect this itself.
  */
 public class MesosExternalShuffleClient extends ExternalShuffleClient {
-  private final Logger logger = LoggerFactory.getLogger(MesosExternalShuffleClient.class);
+  private static final Logger logger = LoggerFactory.getLogger(MesosExternalShuffleClient.class);
 
   private final ScheduledExecutorService heartbeaterThread =
       Executors.newSingleThreadScheduledExecutor(

common/network-yarn/src/main/java/org/apache/spark/network/yarn/YarnShuffleService.java

@@ -58,7 +58,7 @@ import org.apache.spark.network.yarn.util.HadoopConfigProvider;
  * the service's.
  */
 public class YarnShuffleService extends AuxiliaryService {
-  private final Logger logger = LoggerFactory.getLogger(YarnShuffleService.class);
+  private static final Logger logger = LoggerFactory.getLogger(YarnShuffleService.class);
 
   // Port on which the shuffle server listens for fetch requests
   private static final String SPARK_SHUFFLE_SERVICE_PORT_KEY = "spark.shuffle.service.port";

core/src/main/java/org/apache/spark/memory/TaskMemoryManager.java

@@ -53,7 +53,7 @@ import org.apache.spark.util.Utils;
  */
 public class TaskMemoryManager {
 
-  private final Logger logger = LoggerFactory.getLogger(TaskMemoryManager.class);
+  private static final Logger logger = LoggerFactory.getLogger(TaskMemoryManager.class);
 
   /** The number of bits used to address the page table. */
   private static final int PAGE_NUMBER_BITS = 13;

core/src/main/java/org/apache/spark/shuffle/sort/BypassMergeSortShuffleWriter.java

@@ -73,7 +73,7 @@ import org.apache.spark.util.Utils;
  */
 final class BypassMergeSortShuffleWriter<K, V> extends ShuffleWriter<K, V> {
 
-  private final Logger logger = LoggerFactory.getLogger(BypassMergeSortShuffleWriter.class);
+  private static final Logger logger = LoggerFactory.getLogger(BypassMergeSortShuffleWriter.class);
 
   private final int fileBufferSize;
   private final boolean transferToEnabled;

core/src/main/java/org/apache/spark/shuffle/sort/ShuffleExternalSorter.java

@@ -62,7 +62,7 @@ import org.apache.spark.util.Utils;
  */
 final class ShuffleExternalSorter extends MemoryConsumer {
 
-  private final Logger logger = LoggerFactory.getLogger(ShuffleExternalSorter.class);
+  private static final Logger logger = LoggerFactory.getLogger(ShuffleExternalSorter.class);
 
   @VisibleForTesting
   static final int DISK_WRITE_BUFFER_SIZE = 1024 * 1024;

core/src/main/java/org/apache/spark/shuffle/sort/UnsafeShuffleWriter.java

@@ -56,7 +56,7 @@ import org.apache.spark.util.Utils;
 @Private
 public class UnsafeShuffleWriter<K, V> extends ShuffleWriter<K, V> {
 
-  private final Logger logger = LoggerFactory.getLogger(UnsafeShuffleWriter.class);
+  private static final Logger logger = LoggerFactory.getLogger(UnsafeShuffleWriter.class);
 
   private static final ClassTag<Object> OBJECT_CLASS_TAG = ClassTag$.MODULE$.Object();
 

core/src/main/java/org/apache/spark/unsafe/map/BytesToBytesMap.java

@@ -64,7 +64,7 @@ import org.apache.spark.util.collection.unsafe.sort.UnsafeSorterSpillWriter;
  */
 public final class BytesToBytesMap extends MemoryConsumer {
 
-  private final Logger logger = LoggerFactory.getLogger(BytesToBytesMap.class);
+  private static final Logger logger = LoggerFactory.getLogger(BytesToBytesMap.class);
 
   private static final HashMapGrowthStrategy growthStrategy = HashMapGrowthStrategy.DOUBLING;
 

core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java

@@ -44,7 +44,7 @@ import org.apache.spark.util.Utils;
  */
 public final class UnsafeExternalSorter extends MemoryConsumer {
 
-  private final Logger logger = LoggerFactory.getLogger(UnsafeExternalSorter.class);
+  private static final Logger logger = LoggerFactory.getLogger(UnsafeExternalSorter.class);
 
   @Nullable
   private final PrefixComparator prefixComparator;