HDFS-8083. Move dfs.client.write.* conf from DFSConfigKeys to HdfsClientConfigKeys.Write.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java

@@ -19,6 +19,9 @@ package org.apache.hadoop.hdfs.client;
 
 /** Client configuration properties */
 public interface HdfsClientConfigKeys {
+  long SECOND = 1000L;
+  long MINUTE = 60 * SECOND;
+
   String  DFS_BLOCK_SIZE_KEY = "dfs.blocksize";
   long    DFS_BLOCK_SIZE_DEFAULT = 128*1024*1024;
   String  DFS_REPLICATION_KEY = "dfs.replication";
@@ -65,7 +68,50 @@ public interface HdfsClientConfigKeys {
     int     CONNECTION_RETRIES_DEFAULT = 0;
     String  CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_KEY = PREFIX + "connection.retries.on.timeouts";
     int     CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_DEFAULT = 0;
+  }
   
+  interface Write {
+    String PREFIX = HdfsClientConfigKeys.PREFIX + "write.";
+
+    String  MAX_PACKETS_IN_FLIGHT_KEY = PREFIX + "max-packets-in-flight";
+    int     MAX_PACKETS_IN_FLIGHT_DEFAULT = 80;
+    String  EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_KEY = PREFIX + "exclude.nodes.cache.expiry.interval.millis";
+    long    EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT = 10*MINUTE;
+
+    interface ByteArrayManager {
+      String PREFIX = Write.PREFIX + "byte-array-manager.";
+
+      String  ENABLED_KEY = PREFIX + "enabled";
+      boolean ENABLED_DEFAULT = false;
+      String  COUNT_THRESHOLD_KEY = PREFIX + "count-threshold";
+      int     COUNT_THRESHOLD_DEFAULT = 128;
+      String  COUNT_LIMIT_KEY = PREFIX + "count-limit";
+      int     COUNT_LIMIT_DEFAULT = 2048;
+      String  COUNT_RESET_TIME_PERIOD_MS_KEY = PREFIX + "count-reset-time-period-ms";
+      long    COUNT_RESET_TIME_PERIOD_MS_DEFAULT = 10*SECOND;
+    }
+  }
+
+  interface BlockWrite {
+    String PREFIX = HdfsClientConfigKeys.PREFIX + "block.write.";
+
+    String  RETRIES_KEY = PREFIX + "retries";
+    int     RETRIES_DEFAULT = 3;
+    String  LOCATEFOLLOWINGBLOCK_RETRIES_KEY = PREFIX + "locateFollowingBlock.retries";
+    int     LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT = 5;
+    String  LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_KEY = PREFIX + "locateFollowingBlock.initial.delay.ms";
+    int     LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_DEFAULT = 400;
+
+    interface ReplaceDatanodeOnFailure {
+      String PREFIX = BlockWrite.PREFIX + "replace-datanode-on-failure.";
+
+      String  ENABLE_KEY = PREFIX + "enable";
+      boolean ENABLE_DEFAULT = true;
+      String  POLICY_KEY = PREFIX + "policy";
+      String  POLICY_DEFAULT = "DEFAULT";
+      String  BEST_EFFORT_KEY = PREFIX + "best-effort";
+      boolean BEST_EFFORT_DEFAULT = false;
+    }
   }
 
   /** HTTP client configuration properties */

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/EnumSetParam.java

@@ -39,7 +39,7 @@ abstract class EnumSetParam<E extends Enum<E>> extends Param<EnumSet<E>, EnumSet
   }
 
   static <E extends Enum<E>> EnumSet<E> toEnumSet(final Class<E> clazz,
-      final E... values) {
+      final E[] values) {
     final EnumSet<E> set = EnumSet.noneOf(clazz);
     set.addAll(Arrays.asList(values));
     return set;

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -110,6 +110,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-7933. fsck should also report decommissioning replicas.
     (Xiaoyu Yao via cnauroth)
 
+    HDFS-8083. Move dfs.client.write.* conf from DFSConfigKeys to 
+    HdfsClientConfigKeys.Write.  (szetszwo)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -766,37 +766,87 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final int     DFS_CLIENT_FAILOVER_CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_DEFAULT
       = HdfsClientConfigKeys.Failover.CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_DEFAULT;
   
+  // client write confs are moved to HdfsClientConfigKeys.Write 
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_MAX_PACKETS_IN_FLIGHT_KEY
+      = HdfsClientConfigKeys.Write.MAX_PACKETS_IN_FLIGHT_KEY;
+  @Deprecated
+  public static final int     DFS_CLIENT_WRITE_MAX_PACKETS_IN_FLIGHT_DEFAULT
+      = HdfsClientConfigKeys.Write.MAX_PACKETS_IN_FLIGHT_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL
+      = HdfsClientConfigKeys.Write.EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_KEY;
+  @Deprecated
+  public static final long    DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT
+      = HdfsClientConfigKeys.Write.EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT; // 10 minutes, in ms
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_ENABLED_KEY
+      = HdfsClientConfigKeys.Write.ByteArrayManager.ENABLED_KEY;
+  @Deprecated
+  public static final boolean DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_ENABLED_DEFAULT
+      = HdfsClientConfigKeys.Write.ByteArrayManager.ENABLED_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_KEY
+      = HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_THRESHOLD_KEY;
+  @Deprecated
+  public static final int     DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_DEFAULT
+      = HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_THRESHOLD_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_LIMIT_KEY
+      = HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_LIMIT_KEY;
+  @Deprecated
+  public static final int     DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_LIMIT_DEFAULT
+      = HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_LIMIT_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_KEY
+      = HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_RESET_TIME_PERIOD_MS_KEY;
+  @Deprecated
+  public static final long    DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_DEFAULT
+      = HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_RESET_TIME_PERIOD_MS_DEFAULT;
+
+  // client block.write confs are moved to HdfsClientConfigKeys.BlockWrite 
+  @Deprecated
+  public static final String  DFS_CLIENT_BLOCK_WRITE_RETRIES_KEY
+      = HdfsClientConfigKeys.BlockWrite.RETRIES_KEY;
+  @Deprecated
+  public static final int     DFS_CLIENT_BLOCK_WRITE_RETRIES_DEFAULT
+      = HdfsClientConfigKeys.BlockWrite.RETRIES_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY
+      = HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_KEY;
+  @Deprecated
+  public static final int     DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT
+      = HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY
+      = HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_KEY;
+  @Deprecated
+  public static final int     DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_DEFAULT
+      = HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_KEY
+      = HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_KEY;
+  @Deprecated
+  public static final boolean DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_DEFAULT
+      = HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_KEY
+      = HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_DEFAULT
+      = HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_DEFAULT;
+  @Deprecated
+  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_KEY
+      = HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.BEST_EFFORT_KEY;
+  @Deprecated
+  public static final boolean DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_DEFAULT
+      = HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.BEST_EFFORT_DEFAULT;
+
 
   
   
-  public static final String  DFS_CLIENT_WRITE_MAX_PACKETS_IN_FLIGHT_KEY = "dfs.client.write.max-packets-in-flight";
-  public static final int     DFS_CLIENT_WRITE_MAX_PACKETS_IN_FLIGHT_DEFAULT = 80;
   public static final String  DFS_CLIENT_WRITE_PACKET_SIZE_KEY = "dfs.client-write-packet-size";
   public static final int     DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT = 64*1024;
-  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_ENABLED_KEY
-      = "dfs.client.write.byte-array-manager.enabled";
-  public static final boolean DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_ENABLED_DEFAULT
-      = false;
-  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_KEY
-      = "dfs.client.write.byte-array-manager.count-threshold";
-  public static final int     DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_DEFAULT
-      = 128;
-  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_LIMIT_KEY
-      = "dfs.client.write.byte-array-manager.count-limit";
-  public static final int     DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_LIMIT_DEFAULT
-      = 2048;
-  public static final String  DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_KEY
-      = "dfs.client.write.byte-array-manager.count-reset-time-period-ms";
-  public static final long    DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_DEFAULT
-      = 10L * 1000;
-  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_KEY = "dfs.client.block.write.replace-datanode-on-failure.enable";
-  public static final boolean DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_DEFAULT = true;
-  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_KEY = "dfs.client.block.write.replace-datanode-on-failure.policy";
-  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_DEFAULT = "DEFAULT";
-  public static final String  DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_KEY = "dfs.client.block.write.replace-datanode-on-failure.best-effort";
-  public static final boolean DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_DEFAULT = false;
-  public static final String  DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL = "dfs.client.write.exclude.nodes.cache.expiry.interval.millis";
-  public static final long    DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT = 10 * 60 * 1000; // 10 minutes, in ms
 
   public static final String  DFS_CLIENT_SOCKET_TIMEOUT_KEY = "dfs.client.socket-timeout";
   public static final String  DFS_CLIENT_SOCKET_CACHE_CAPACITY_KEY = "dfs.client.socketcache.capacity";
@@ -827,13 +877,7 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final String  DFS_CLIENT_HTTPS_NEED_AUTH_KEY = "dfs.client.https.need-auth";
   public static final boolean DFS_CLIENT_HTTPS_NEED_AUTH_DEFAULT = false;
   // Much code in hdfs is not yet updated to use these keys.
-  public static final String  DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY = "dfs.client.block.write.locateFollowingBlock.retries";
-  public static final int     DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT = 5;
   // the initial delay (unit is ms) for locateFollowingBlock, the delay time will increase exponentially(double) for each retry.
-  public static final String  DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY = "dfs.client.block.write.locateFollowingBlock.initial.delay.ms";
-  public static final int     DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_DEFAULT = 400;
-  public static final String  DFS_CLIENT_BLOCK_WRITE_RETRIES_KEY = "dfs.client.block.write.retries";
-  public static final int     DFS_CLIENT_BLOCK_WRITE_RETRIES_DEFAULT = 3;
   public static final String  DFS_CLIENT_MAX_BLOCK_ACQUIRE_FAILURES_KEY = "dfs.client.max.block.acquire.failures";
   public static final int     DFS_CLIENT_MAX_BLOCK_ACQUIRE_FAILURES_DEFAULT = 3;
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DataStreamer.java

@@ -43,6 +43,7 @@ import java.util.concurrent.atomic.AtomicReference;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.fs.StorageType;
+import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.client.impl.DfsClientConf;
 import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
 import org.apache.hadoop.hdfs.protocol.DSQuotaExceededException;
@@ -1029,7 +1030,7 @@ class DataStreamer extends Daemon {
               .append("The current failed datanode replacement policy is ")
               .append(dfsClient.dtpReplaceDatanodeOnFailure).append(", and ")
               .append("a client may configure this via '")
-              .append(DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_KEY)
+              .append(HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY)
               .append("' in its configuration.")
               .toString());
     }
@@ -1240,7 +1241,7 @@ class DataStreamer extends Daemon {
           }
           DFSClient.LOG.warn("Failed to replace datanode."
               + " Continue with the remaining datanodes since "
-              + DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_KEY
+              + HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.BEST_EFFORT_KEY
               + " is set to true.", ioe);
         }
       }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/impl/DfsClientConf.java

@@ -21,12 +21,6 @@ import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCK_SIZE_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCK_SIZE_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_RETRIES_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_RETRIES_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_CACHED_CONN_RETRY_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_CACHED_CONN_RETRY_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_DATANODE_RESTART_TIMEOUT_DEFAULT;
@@ -41,10 +35,6 @@ import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_SOCKET_CACHE_EXPIR
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_USE_DN_HOSTNAME;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_USE_DN_HOSTNAME_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_REPLICATION_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_REPLICATION_KEY;
@@ -148,27 +138,28 @@ public class DfsClientConf {
     socketTimeout = conf.getInt(DFS_CLIENT_SOCKET_TIMEOUT_KEY,
         HdfsServerConstants.READ_TIMEOUT);
     /** dfs.write.packet.size is an internal config variable */
-    writePacketSize = conf.getInt(DFS_CLIENT_WRITE_PACKET_SIZE_KEY,
+    writePacketSize = conf.getInt(
-        DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT);
+        DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY,
+        DFSConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_DEFAULT);
     writeMaxPackets = conf.getInt(
-        DFSConfigKeys.DFS_CLIENT_WRITE_MAX_PACKETS_IN_FLIGHT_KEY,
+        HdfsClientConfigKeys.Write.MAX_PACKETS_IN_FLIGHT_KEY,
-        DFSConfigKeys.DFS_CLIENT_WRITE_MAX_PACKETS_IN_FLIGHT_DEFAULT);
+        HdfsClientConfigKeys.Write.MAX_PACKETS_IN_FLIGHT_DEFAULT);
     
     final boolean byteArrayManagerEnabled = conf.getBoolean(
-        DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_ENABLED_KEY,
+        HdfsClientConfigKeys.Write.ByteArrayManager.ENABLED_KEY,
-        DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_ENABLED_DEFAULT);
+        HdfsClientConfigKeys.Write.ByteArrayManager.ENABLED_DEFAULT);
     if (!byteArrayManagerEnabled) {
       writeByteArrayManagerConf = null;
     } else {
       final int countThreshold = conf.getInt(
-          DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_KEY,
+          HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_THRESHOLD_KEY,
-          DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_DEFAULT);
+          HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_THRESHOLD_DEFAULT);
       final int countLimit = conf.getInt(
-          DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_LIMIT_KEY,
+          HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_LIMIT_KEY,
-          DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_LIMIT_DEFAULT);
+          HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_LIMIT_DEFAULT);
       final long countResetTimePeriodMs = conf.getLong(
-          DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_KEY,
+          HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_RESET_TIME_PERIOD_MS_KEY,
-          DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_DEFAULT);
+          HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_RESET_TIME_PERIOD_MS_DEFAULT);
       writeByteArrayManagerConf = new ByteArrayManager.Conf(
           countThreshold, countLimit, countResetTimePeriodMs); 
     }
@@ -179,20 +170,21 @@ public class DfsClientConf {
         DFS_REPLICATION_KEY, DFS_REPLICATION_DEFAULT);
     taskId = conf.get("mapreduce.task.attempt.id", "NONMAPREDUCE");
     excludedNodesCacheExpiry = conf.getLong(
-        DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL,
+        HdfsClientConfigKeys.Write.EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_KEY,
-        DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT);
+        HdfsClientConfigKeys.Write.EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT);
     prefetchSize = conf.getLong(DFS_CLIENT_READ_PREFETCH_SIZE_KEY,
         10 * defaultBlockSize);
     numCachedConnRetry = conf.getInt(DFS_CLIENT_CACHED_CONN_RETRY_KEY,
         DFS_CLIENT_CACHED_CONN_RETRY_DEFAULT);
-    numBlockWriteRetry = conf.getInt(DFS_CLIENT_BLOCK_WRITE_RETRIES_KEY,
+    numBlockWriteRetry = conf.getInt(
-        DFS_CLIENT_BLOCK_WRITE_RETRIES_DEFAULT);
+        HdfsClientConfigKeys.BlockWrite.RETRIES_KEY,
+        HdfsClientConfigKeys.BlockWrite.RETRIES_DEFAULT);
     numBlockWriteLocateFollowingRetry = conf.getInt(
-        DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY,
+        HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_KEY,
-        DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT);
+        HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT);
     blockWriteLocateFollowingInitialDelayMs = conf.getInt(
-        DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY,
+        HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_KEY,
-        DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_DEFAULT);
+        HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_DEFAULT);
     uMask = FsPermission.getUMask(conf);
     connectToDnViaHostname = conf.getBoolean(DFS_CLIENT_USE_DN_HOSTNAME,
         DFS_CLIENT_USE_DN_HOSTNAME_DEFAULT);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/ReplaceDatanodeOnFailure.java

@@ -21,7 +21,7 @@ import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 
 /**
@@ -115,7 +115,7 @@ public class ReplaceDatanodeOnFailure {
     if (policy == Policy.DISABLE) {
       throw new UnsupportedOperationException(
           "This feature is disabled.  Please refer to "
-          + DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_KEY
+          + HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_KEY
           + " configuration property.");
     }
   }
@@ -156,23 +156,23 @@ public class ReplaceDatanodeOnFailure {
   public static ReplaceDatanodeOnFailure get(final Configuration conf) {
     final Policy policy = getPolicy(conf);
     final boolean bestEffort = conf.getBoolean(
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_KEY,
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.BEST_EFFORT_KEY,
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_DEFAULT);
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.BEST_EFFORT_DEFAULT);
     
     return new ReplaceDatanodeOnFailure(policy, bestEffort);
   }
 
   private static Policy getPolicy(final Configuration conf) {
     final boolean enabled = conf.getBoolean(
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_KEY,
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_KEY,
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_DEFAULT);
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_DEFAULT);
     if (!enabled) {
       return Policy.DISABLE;
     }
 
     final String policy = conf.get(
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_KEY,
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY,
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_DEFAULT);
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_DEFAULT);
     for(int i = 1; i < Policy.values().length; i++) {
       final Policy p = Policy.values()[i];
       if (p.name().equalsIgnoreCase(policy)) {
@@ -180,7 +180,7 @@ public class ReplaceDatanodeOnFailure {
       }
     }
     throw new HadoopIllegalArgumentException("Illegal configuration value for "
-        + DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_KEY
+        + HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY
         + ": " + policy);
   }
 
@@ -188,13 +188,13 @@ public class ReplaceDatanodeOnFailure {
   public static void write(final Policy policy,
       final boolean bestEffort, final Configuration conf) {
     conf.setBoolean(
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_ENABLE_KEY,
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_KEY,
         policy != Policy.DISABLE);
     conf.set(
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_POLICY_KEY,
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY,
         policy.name());
     conf.setBoolean(
-        DFSConfigKeys.DFS_CLIENT_WRITE_REPLACE_DATANODE_ON_FAILURE_BEST_EFFORT_KEY,
+        HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.BEST_EFFORT_KEY,
         bestEffort);
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientProtocolForPipelineRecovery.java

@@ -23,18 +23,16 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.namenode.LeaseExpiredException;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
 import org.apache.hadoop.hdfs.tools.DFSAdmin;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.io.IOUtils;
 import org.junit.Assert;
 import org.junit.Test;
-
 import org.mockito.Mockito;
-import org.mockito.stubbing.Answer;
 
 /**
  * This tests pipeline recovery related client protocol works correct or not.
@@ -130,7 +128,7 @@ public class TestClientProtocolForPipelineRecovery {
     DFSClientFaultInjector.instance = faultInjector;
     Configuration conf = new HdfsConfiguration();
 
-    conf.setInt(DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY, 3);
+    conf.setInt(HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_KEY, 3);
     MiniDFSCluster cluster = null;
 
     try {
@@ -147,7 +145,7 @@ public class TestClientProtocolForPipelineRecovery {
       // Read should succeed.
       FSDataInputStream in = fileSys.open(file);
       try {
-        int c = in.read();
+        in.read();
         // Test will fail with BlockMissingException if NN does not update the
         // replica state based on the latest report.
       } catch (org.apache.hadoop.hdfs.BlockMissingException bme) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientExcludedNodes.java

@@ -21,15 +21,14 @@ import static org.junit.Assert.fail;
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.MiniDFSCluster.DataNodeProperties;
+import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.util.ThreadUtil;
-
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -87,13 +86,12 @@ public class TestDFSClientExcludedNodes {
   public void testExcludedNodesForgiveness() throws IOException {
     // Forgive nodes in under 2.5s for this test case.
     conf.setLong(
-        DFSConfigKeys.DFS_CLIENT_WRITE_EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL,
+        HdfsClientConfigKeys.Write.EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_KEY,
         2500);
     // We'll be using a 512 bytes block size just for tests
     // so making sure the checksum bytes too match it.
     conf.setInt("io.bytes.per.checksum", 512);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3).build();
-    List<DataNodeProperties> props = cluster.dataNodes;
     FileSystem fs = cluster.getFileSystem();
     Path filePath = new Path("/testForgivingExcludedNodes");
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java

@@ -228,7 +228,7 @@ public class TestDFSClientRetries {
   { 
     final String exceptionMsg = "Nope, not replicated yet...";
     final int maxRetries = 1; // Allow one retry (total of two calls)
-    conf.setInt(DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY, maxRetries);
+    conf.setInt(HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_KEY, maxRetries);
     
     NamenodeProtocols mockNN = mock(NamenodeProtocols.class);
     Answer<Object> answer = new ThrowsException(new IOException()) {
@@ -1128,7 +1128,7 @@ public class TestDFSClientRetries {
   @Test
   public void testDFSClientConfigurationLocateFollowingBlockInitialDelay()
       throws Exception {
-    // test if DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY
+    // test if HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY
     // is not configured, verify DFSClient uses the default value 400.
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
     try {
@@ -1138,10 +1138,11 @@ public class TestDFSClientRetries {
       assertEquals(client.getConf().
           getBlockWriteLocateFollowingInitialDelayMs(), 400);
 
-      // change DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY,
+      // change HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY,
       // verify DFSClient uses the configured value 1000.
-      conf.setInt(DFSConfigKeys.
+      conf.setInt(
-          DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_KEY, 1000);
+          HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_KEY,
+          1000);
       client = new DFSClient(null, nn, conf, null);
       assertEquals(client.getConf().
           getBlockWriteLocateFollowingInitialDelayMs(), 1000);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNamenodeCapacityReport.java

@@ -18,8 +18,8 @@
 package org.apache.hadoop.hdfs.server.namenode;
 
 
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY;
+import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.io.IOException;
@@ -38,6 +38,7 @@ import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
@@ -169,7 +170,7 @@ public class TestNamenodeCapacityReport {
   public void testXceiverCount() throws Exception {
     Configuration conf = new HdfsConfiguration();
     // retry one time, if close fails
-    conf.setInt(DFS_CLIENT_BLOCK_WRITE_LOCATEFOLLOWINGBLOCK_RETRIES_KEY, 1);
+    conf.setInt(HdfsClientConfigKeys.BlockWrite.LOCATEFOLLOWINGBLOCK_RETRIES_KEY, 1);
     MiniDFSCluster cluster = null;
 
     final int nodes = 8;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/util/TestByteArrayManager.java

@@ -34,8 +34,8 @@ import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.commons.logging.impl.Log4JLogger;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
+import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.util.ByteArrayManager.Counter;
 import org.apache.hadoop.hdfs.util.ByteArrayManager.CounterMap;
 import org.apache.hadoop.hdfs.util.ByteArrayManager.FixedLengthManager;
@@ -578,9 +578,9 @@ public class TestByteArrayManager {
         new ByteArrayManager.NewByteArrayWithoutLimit(),
         new NewByteArrayWithLimit(maxArrays),
         new ByteArrayManager.Impl(new ByteArrayManager.Conf(
-            DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_THRESHOLD_DEFAULT,
+            HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_THRESHOLD_DEFAULT,
             maxArrays,
-            DFSConfigKeys.DFS_CLIENT_WRITE_BYTE_ARRAY_MANAGER_COUNT_RESET_TIME_PERIOD_MS_DEFAULT))
+            HdfsClientConfigKeys.Write.ByteArrayManager.COUNT_RESET_TIME_PERIOD_MS_DEFAULT))
     };
     final double[] avg = new double[impls.length];