HADOOP-17552. Change ipc.client.rpc-timeout.ms from 0 to 120000 by default to avoid potential hang. (#2727)

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

@@ -58,7 +58,7 @@ public class CommonConfigurationKeys extends CommonConfigurationKeysPublic {
   public static final String IPC_CLIENT_RPC_TIMEOUT_KEY =
       "ipc.client.rpc-timeout.ms";
   /** Default value for IPC_CLIENT_RPC_TIMEOUT_KEY. */
-  public static final int IPC_CLIENT_RPC_TIMEOUT_DEFAULT = 0;
+  public static final int IPC_CLIENT_RPC_TIMEOUT_DEFAULT = 120000;
   /** Responses larger than this will be logged */
   public static final String  IPC_SERVER_RPC_MAX_RESPONSE_SIZE_KEY =
     "ipc.server.max.response.size";

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

@@ -2383,9 +2383,10 @@
 
 <property>
   <name>ipc.client.rpc-timeout.ms</name>
-  <value>0</value>
+  <value>120000</value>
   <description>Timeout on waiting response from server, in milliseconds.
-  If ipc.client.ping is set to true and this rpc-timeout is greater than
+  If this rpc-timeout is 0, it means no timeout. If this rpc-timeout is greater
+  than 0, and ipc.client.ping is set to true, and this rpc-timeout is greater than
   the value of ipc.ping.interval, the effective value of the rpc-timeout is
   rounded up to multiple of ipc.ping.interval.
   </description>

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/TestIPC.java

@@ -1456,6 +1456,7 @@ public class TestIPC {
   @Test
   public void testClientGetTimeout() throws IOException {
     Configuration config = new Configuration();
+    config.setInt(CommonConfigurationKeys.IPC_CLIENT_RPC_TIMEOUT_KEY, 0);
     assertThat(Client.getTimeout(config)).isEqualTo(-1);
   }