HADOOP-16504. Increase ipc.server.listen.queue.size default from 128 to 256. Contributed by Lisheng Sun.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CommonConfigurationKeysPublic.java

@@ -417,7 +417,7 @@ public class CommonConfigurationKeysPublic {
   public static final String  IPC_SERVER_LISTEN_QUEUE_SIZE_KEY =
     "ipc.server.listen.queue.size";
   /** Default value for IPC_SERVER_LISTEN_QUEUE_SIZE_KEY */
-  public static final int     IPC_SERVER_LISTEN_QUEUE_SIZE_DEFAULT = 128;
+  public static final int     IPC_SERVER_LISTEN_QUEUE_SIZE_DEFAULT = 256;
   /**
    * @see
    * <a href="{@docRoot}/../hadoop-project-dist/hadoop-common/core-default.xml">

hadoop-common-project/hadoop-common/src/main/resources/core-default.xml

@@ -2196,7 +2196,7 @@
 
 <property>
   <name>ipc.server.listen.queue.size</name>
-  <value>128</value>
+  <value>256</value>
   <description>Indicates the length of the listen queue for servers accepting
                client connections.
   </description>