HDDS-1531. Disable the sync flag by default during chunk writes in Datanode (#820). Contributed by Shashikant Banerjee.

hadoop-hdds/common/src/main/java/org/apache/hadoop/ozone/OzoneConfigKeys.java

@@ -56,7 +56,7 @@ public final class OzoneConfigKeys {
 
   public static final String DFS_CONTAINER_CHUNK_WRITE_SYNC_KEY =
       "dfs.container.chunk.write.sync";
-  public static final boolean DFS_CONTAINER_CHUNK_WRITE_SYNC_DEFAULT = true;
+  public static final boolean DFS_CONTAINER_CHUNK_WRITE_SYNC_DEFAULT = false;
   /**
    * Ratis Port where containers listen to.
    */

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -54,7 +54,7 @@
   </property>
   <property>
     <name>dfs.container.chunk.write.sync</name>
-    <value>true</value>
+    <value>false</value>
     <tag>OZONE, CONTAINER, MANAGEMENT</tag>
     <description>Determines whether the chunk writes in the container happen as
       sync I/0 or buffered I/O operation.