HDFS-11702. Remove indefinite caching of key provider uri in DFSClient. Contributed by Rushabh S Shah.

(cherry picked from commit cef2815cf48154fe82f44082dcbdce6373c81284)

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSClient.java

@@ -242,7 +242,6 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
       new DFSHedgedReadMetrics();
   private static ThreadPoolExecutor HEDGED_READ_THREAD_POOL;
   private final int smallBufferSize;
-  private URI keyProviderUri = null;
 
   public DfsClientConf getConf() {
     return dfsClientConf;
@@ -3017,10 +3016,7 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
    * @throws IOException
    */
   URI getKeyProviderUri() throws IOException {
-    if (keyProviderUri != null) {
-      return keyProviderUri;
-    }
-
+    URI keyProviderUri = null;
     // Lookup the secret in credentials object for namenodeuri.
     Credentials credentials = ugi.getCredentials();
     byte[] keyProviderUriBytes = credentials.getSecretKey(getKeyProviderMapKey());
@@ -3052,14 +3048,6 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
     return clientContext.getKeyProviderCache().get(conf, getKeyProviderUri());
   }
 
-  /*
-   * Should be used only for testing.
-   */
-  @VisibleForTesting
-  public void setKeyProviderUri(URI providerUri) {
-    this.keyProviderUri = providerUri;
-  }
-
   @VisibleForTesting
   public void setKeyProvider(KeyProvider provider) {
     clientContext.getKeyProviderCache().setKeyProvider(conf, provider);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZones.java

@@ -1721,7 +1721,6 @@ public class TestEncryptionZones {
     credentials.addSecretKey(lookUpKey,
         DFSUtilClient.string2Bytes(dummyKeyProvider));
     client.ugi.addCredentials(credentials);
-    client.setKeyProviderUri(null);
     Assert.assertEquals("Client Key provider is different from provider in "
         + "credentials map", dummyKeyProvider,
         client.getKeyProviderUri().toString());
@@ -1743,7 +1742,6 @@ public class TestEncryptionZones {
         CommonConfigurationKeysPublic.HADOOP_SECURITY_KEY_PROVIDER_PATH,
         dummyKeyProviderUri1);
     DFSClient mockClient = Mockito.spy(cluster.getFileSystem().getClient());
-    mockClient.setKeyProviderUri(null);
     // Namenode returning null as keyProviderUri in FSServerDefaults.
     FsServerDefaults serverDefaultsWithKeyProviderNull =
         getTestServerDefaults(null);
@@ -1755,7 +1753,6 @@ public class TestEncryptionZones {
     Mockito.verify(mockClient, Mockito.times(1)).getServerDefaults();
 
     String dummyKeyProviderUri2 = "dummy://foo:bar@test_provider2";
-    mockClient.setKeyProviderUri(null);
     FsServerDefaults serverDefaultsWithDummyKeyProvider =
         getTestServerDefaults(dummyKeyProviderUri2);
     // Namenode returning dummyKeyProvider2 in serverDefaults.
@@ -1784,8 +1781,6 @@ public class TestEncryptionZones {
     // Unset the provider path in conf
     clusterConf.unset(
         CommonConfigurationKeysPublic.HADOOP_SECURITY_KEY_PROVIDER_PATH);
-    // Nullify the cached value for key provider uri on client
-    cluster.getFileSystem().getClient().setKeyProviderUri(null);
     // Even after unsetting the local conf, the client key provider should be
     // the same as namenode's provider.
     Assert.assertEquals("Key Provider for client and namenode are different",
@@ -1796,8 +1791,6 @@ public class TestEncryptionZones {
     clusterConf.set(
         CommonConfigurationKeysPublic.HADOOP_SECURITY_KEY_PROVIDER_PATH,
         "dummy://foo:bar@test_provider1");
-    // Nullify the cached value for key provider uri on client
-    cluster.getFileSystem().getClient().setKeyProviderUri(null);
     // Even after pointing the conf to some dummy provider, the client key
     // provider should be the same as namenode's provider.
     Assert.assertEquals("Key Provider for client and namenode are different",
@@ -1832,8 +1825,6 @@ public class TestEncryptionZones {
     // Creating a fake serverdefaults so that we can simulate namenode not
     // being upgraded.
     DFSClient spyClient = Mockito.spy(cluster.getFileSystem().getClient());
-    // Clear the cache value of keyProviderUri on client side.
-    spyClient.setKeyProviderUri(null);
     Mockito.doReturn(spyServerDefaults).when(spyClient).getServerDefaults();
 
     // Since FsServerDefaults#keyProviderUri is null, the client