HADOOP-14880. [KMS] Document&test missing KMS client side configs. Contributed by Gabor Bota.

(cherry picked from commit 97c70c7ac6881f87eee1575bcbdd28b31ecac231)

Conflicts:
	hadoop-common-project/hadoop-kms/src/test/java/org/apache/hadoop/crypto/key/kms/server/TestKMS.java
(cherry picked from commit 21b9e4fb979ecbc8f254b76f6ed86e6ef63d74f3)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/KMSClientProvider.java

@@ -114,10 +114,6 @@ public class KMSClientProvider extends KeyProvider implements CryptoExtension,
 
   private static final String CONFIG_PREFIX = "hadoop.security.kms.client.";
 
-  /* It's possible to specify a timeout, in seconds, in the config file */
-  public static final String TIMEOUT_ATTR = CONFIG_PREFIX + "timeout";
-  public static final int DEFAULT_TIMEOUT = 60;
-
   /* Number of times to retry authentication in the event of auth failure
    * (normally happens due to stale authToken) 
    */
@@ -433,7 +429,9 @@ public class KMSClientProvider extends KeyProvider implements CryptoExtension,
         throw new IOException(ex);
       }
     }
-    int timeout = conf.getInt(TIMEOUT_ATTR, DEFAULT_TIMEOUT);
+    int timeout = conf.getInt(
+            CommonConfigurationKeysPublic.KMS_CLIENT_TIMEOUT_SECONDS,
+            CommonConfigurationKeysPublic.KMS_CLIENT_TIMEOUT_DEFAULT);
     authRetry = conf.getInt(AUTH_RETRY, DEFAULT_AUTH_RETRY);
     configurator = new TimeoutConnConfigurator(timeout, sslFactory);
     encKeyVersionQueue =

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

@@ -688,6 +688,15 @@ public class CommonConfigurationKeysPublic {
   /** Default value for KMS_CLIENT_ENC_KEY_CACHE_EXPIRY (12 hrs)*/
   public static final int KMS_CLIENT_ENC_KEY_CACHE_EXPIRY_DEFAULT = 43200000;
 
+  /**
+   * @see
+   * <a href="{@docRoot}/../hadoop-project-dist/hadoop-common/core-default.xml">
+   * core-default.xml</a>
+   */
+  public static final String KMS_CLIENT_TIMEOUT_SECONDS =
+      "hadoop.security.kms.client.timeout";
+  public static final int KMS_CLIENT_TIMEOUT_DEFAULT = 60;
+
   /**
    * @see
    * <a href="{@docRoot}/../hadoop-project-dist/hadoop-common/core-default.xml">

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

@@ -2138,6 +2138,14 @@
     key will be dropped. Default = 12hrs
   </description>
 </property>
+<property>
+  <name>hadoop.security.kms.client.timeout</name>
+  <value>60</value>
+  <description>
+    Sets value for KMS client connection timeout, and the read timeout
+    to KMS servers.
+  </description>
+</property>
 
 <property>
   <name>hadoop.security.kms.client.failover.sleep.base.millis</name>

hadoop-common-project/hadoop-kms/src/test/java/org/apache/hadoop/crypto/key/kms/server/TestKMS.java

@@ -1635,7 +1635,7 @@ public class TestKMS {
   public void testKMSTimeout() throws Exception {
     File confDir = getTestDir();
     Configuration conf = createBaseKMSConf(confDir);
-    conf.setInt(KMSClientProvider.TIMEOUT_ATTR, 1);
+    conf.setInt(CommonConfigurationKeysPublic.KMS_CLIENT_TIMEOUT_SECONDS, 1);
     writeConf(confDir, conf);
 
     ServerSocket sock;