HDFS-10879. TestEncryptionZonesWithKMS#testReadWrite fails intermittently. Contributed by Xiao Chen.

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

@@ -45,7 +45,9 @@ import org.apache.hadoop.crypto.CipherSuite;
 import org.apache.hadoop.crypto.CryptoProtocolVersion;
 import org.apache.hadoop.crypto.key.JavaKeyStoreProvider;
 import org.apache.hadoop.crypto.key.KeyProvider;
+import org.apache.hadoop.crypto.key.KeyProviderCryptoExtension;
 import org.apache.hadoop.crypto.key.KeyProviderFactory;
+import org.apache.hadoop.crypto.key.kms.server.EagerKeyGeneratorKeyProviderCryptoExtension;
 import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
 import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.fs.FSDataOutputStream;
@@ -734,14 +736,33 @@ public class TestEncryptionZones {
     // Roll the key of the encryption zone
     assertNumZones(1);
     String keyName = dfsAdmin.listEncryptionZones().next().getKeyName();
+    FileEncryptionInfo feInfo1 = getFileEncryptionInfo(encFile1);
     cluster.getNamesystem().getProvider().rollNewVersion(keyName);
+    /**
+     * due to the cache on the server side, client may get old keys.
+     * @see EagerKeyGeneratorKeyProviderCryptoExtension#rollNewVersion(String)
+     */
+    boolean rollSucceeded = false;
+    for (int i = 0; i <= EagerKeyGeneratorKeyProviderCryptoExtension
+        .KMS_KEY_CACHE_SIZE_DEFAULT + CommonConfigurationKeysPublic.
+        KMS_CLIENT_ENC_KEY_CACHE_SIZE_DEFAULT; ++i) {
+      KeyProviderCryptoExtension.EncryptedKeyVersion ekv2 =
+          cluster.getNamesystem().getProvider().generateEncryptedKey(TEST_KEY);
+      if (!(feInfo1.getEzKeyVersionName()
+          .equals(ekv2.getEncryptionKeyVersionName()))) {
+        rollSucceeded = true;
+        break;
+      }
+    }
+    Assert.assertTrue("rollover did not generate a new key even after"
+        + " queue is drained", rollSucceeded);
+
     // Read them back in and compare byte-by-byte
     verifyFilesEqual(fs, baseFile, encFile1, len);
     // Write a new enc file and validate
     final Path encFile2 = new Path(zone, "myfile2");
     DFSTestUtil.createFile(fs, encFile2, len, (short) 1, 0xFEED);
     // FEInfos should be different
-    FileEncryptionInfo feInfo1 = getFileEncryptionInfo(encFile1);
     FileEncryptionInfo feInfo2 = getFileEncryptionInfo(encFile2);
     assertFalse("EDEKs should be different", Arrays
         .equals(feInfo1.getEncryptedDataEncryptionKey(),