HDFS-9086. Rename dfs.datanode.stripedread.threshold.millis to dfs.da…

…tanode.stripedread.timeout.millis. Contributed by Andrew Wang.

Change-Id: Ice86c5d46d29e94087c0f186b941d5394e7ac0e6

hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-EC-7285.txt

@@ -432,3 +432,6 @@
 
     HDFS-9097. Erasure coding: update EC command "-s" flag to "-p" when 
     specifying policy. (zhz)
+
+    HDFS-9086. Rename dfs.datanode.stripedread.threshold.millis to 
+    dfs.datanode.stripedread.timeout.millis. (wang via zhz)

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

@@ -399,8 +399,8 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final int     DFS_DATANODE_STRIPED_READ_THREADS_DEFAULT = 20;
   public static final String  DFS_DATANODE_STRIPED_READ_BUFFER_SIZE_KEY = "dfs.datanode.stripedread.buffer.size";
   public static final int     DFS_DATANODE_STRIPED_READ_BUFFER_SIZE_DEFAULT = 64 * 1024;
-  public static final String  DFS_DATANODE_STRIPED_READ_THRESHOLD_MILLIS_KEY = "dfs.datanode.stripedread.threshold.millis";
-  public static final int     DFS_DATANODE_STRIPED_READ_THRESHOLD_MILLIS_DEFAULT = 5000; //5s
+  public static final String  DFS_DATANODE_STRIPED_READ_TIMEOUT_MILLIS_KEY = "dfs.datanode.stripedread.timeout.millis";
+  public static final int     DFS_DATANODE_STRIPED_READ_TIMEOUT_MILLIS_DEFAULT = 5000; //5s
   public static final String  DFS_DATANODE_STRIPED_BLK_RECOVERY_THREADS_KEY = "dfs.datanode.striped.blockrecovery.threads.size";
   public static final int     DFS_DATANODE_STRIPED_BLK_RECOVERY_THREADS_DEFAULT = 8;
   public static final String  DFS_DATANODE_DNS_INTERFACE_KEY = "dfs.datanode.dns.interface";

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/erasurecode/ErasureCodingWorker.java

@@ -95,16 +95,16 @@ public final class ErasureCodingWorker {
 
   private ThreadPoolExecutor STRIPED_BLK_RECOVERY_THREAD_POOL;
   private ThreadPoolExecutor STRIPED_READ_THREAD_POOL;
-  private final int STRIPED_READ_THRESHOLD_MILLIS;
+  private final int STRIPED_READ_TIMEOUT_MILLIS;
   private final int STRIPED_READ_BUFFER_SIZE;
 
   public ErasureCodingWorker(Configuration conf, DataNode datanode) {
     this.datanode = datanode;
     this.conf = conf;
 
-    STRIPED_READ_THRESHOLD_MILLIS = conf.getInt(
-        DFSConfigKeys.DFS_DATANODE_STRIPED_READ_THRESHOLD_MILLIS_KEY,
-        DFSConfigKeys.DFS_DATANODE_STRIPED_READ_THRESHOLD_MILLIS_DEFAULT);
+    STRIPED_READ_TIMEOUT_MILLIS = conf.getInt(
+        DFSConfigKeys.DFS_DATANODE_STRIPED_READ_TIMEOUT_MILLIS_KEY,
+        DFSConfigKeys.DFS_DATANODE_STRIPED_READ_TIMEOUT_MILLIS_DEFAULT);
     initializeStripedReadThreadPool(conf.getInt(
         DFSConfigKeys.DFS_DATANODE_STRIPED_READ_THREADS_KEY, 
         DFSConfigKeys.DFS_DATANODE_STRIPED_READ_THREADS_DEFAULT));
@@ -556,7 +556,7 @@ private int[] readMinimumStripedData4Recovery(final int[] success)
         try {
           StripingChunkReadResult result =
               StripedBlockUtil.getNextCompletedStripedRead(
-                  readService, futures, STRIPED_READ_THRESHOLD_MILLIS);
+                  readService, futures, STRIPED_READ_TIMEOUT_MILLIS);
           int resultIndex = -1;
           if (result.state == StripingChunkReadResult.SUCCESSFUL) {
             resultIndex = result.index;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/StripedBlockUtil.java

@@ -203,12 +203,12 @@ public static long offsetInBlkToOffsetInBG(int cellSize, int dataBlkNum,
    */
   public static StripingChunkReadResult getNextCompletedStripedRead(
       CompletionService<Void> readService, Map<Future<Void>, Integer> futures,
-      final long threshold) throws InterruptedException {
+      final long timeoutMillis) throws InterruptedException {
     Preconditions.checkArgument(!futures.isEmpty());
     Future<Void> future = null;
     try {
-      if (threshold > 0) {
-        future = readService.poll(threshold, TimeUnit.MILLISECONDS);
+      if (timeoutMillis > 0) {
+        future = readService.poll(timeoutMillis, TimeUnit.MILLISECONDS);
       } else {
         future = readService.take();
       }

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -2403,23 +2403,23 @@
 </property>
 
 <property>
-  <name>dfs.datanode.stripedread.threshold.millis</name>
+  <name>dfs.datanode.stripedread.timeout.millis</name>
   <value>5000</value>
-  <description>datanode striped read threshold in millisecond.
+  <description>Datanode striped read timeout in milliseconds.
   </description>
 </property>
 
 <property>
   <name>dfs.datanode.stripedread.threads</name>
   <value>20</value>
-  <description>datanode striped read thread pool size.
+  <description>Number of threads used by the Datanode for background recovery work.
   </description>
 </property>
 
 <property>
   <name>dfs.datanode.stripedread.buffer.size</name>
   <value>262144</value>
-  <description>datanode striped read buffer size.
+  <description>Datanode striped read buffer size.
   </description>
 </property>
 

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md

@@ -101,7 +101,7 @@ Deployment
 
   Erasure coding background recovery work on the DataNodes can also be tuned via the following configuration parameters:
 
-  1. `dfs.datanode.stripedread.threshold.millis` - Timeout for striped reads. Default value is 5000 ms.
+  1. `dfs.datanode.stripedread.timeout.millis` - Timeout for striped reads. Default value is 5000 ms.
   1. `dfs.datanode.stripedread.threads` - Number of concurrent reader threads. Default value is 20 threads.
   1. `dfs.datanode.stripedread.buffer.size` - Buffer size for reader service. Default value is 256KB.