HADOOP-17308. WASB PageBlobOutputStream.flush succeeds even when flush to storage fails (#2392)

Contributed by Anoop Sam John.

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azure/PageBlobOutputStream.java

@@ -580,6 +580,7 @@ public synchronized void hsync() throws IOException {
       // Restore the interrupted status
       Thread.currentThread().interrupt();
     }
+    checkStreamState();
     LOG.debug("Leaving PageBlobOutputStream#hsync(). Total hsync duration = "
   	  + (System.currentTimeMillis() - start) + " msec.");
   }

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azure/ITestPageBlobOutputStream.java

@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.fs.azure;
+
+import java.io.IOException;
+import java.util.EnumSet;
+
+import org.junit.Test;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.test.LambdaTestUtils;
+
+public class ITestPageBlobOutputStream extends AbstractWasbTestBase {
+
+  private static final Path TEST_FILE_PATH = new Path(
+      "TestPageBlobOutputStream.txt");
+
+  @Override
+  protected AzureBlobStorageTestAccount createTestAccount() throws Exception {
+    Configuration conf = new Configuration();
+    // Configure the page blob directories key so every file created is a page
+    // blob.
+    conf.set(AzureNativeFileSystemStore.KEY_PAGE_BLOB_DIRECTORIES, "/");
+    return AzureBlobStorageTestAccount.create("testpagebloboutputstream",
+        EnumSet.of(AzureBlobStorageTestAccount.CreateOptions.CreateContainer),
+        conf, true);
+  }
+
+  @Test
+  public void testHflush() throws Exception {
+    Path path = fs.makeQualified(TEST_FILE_PATH);
+    FSDataOutputStream os = fs.create(path);
+    os.write(1);
+    os.hflush();
+    // Delete the blob so that Azure call will fail.
+    fs.delete(path, false);
+    os.write(2);
+    LambdaTestUtils.intercept(IOException.class,
+        "The specified blob does not exist", () -> {
+          os.hflush();
+        });
+    LambdaTestUtils.intercept(IOException.class,
+        "The specified blob does not exist", () -> {
+          os.close();
+        });
+  }
+
+  @Test
+  public void testHsync() throws Exception {
+    Path path = fs.makeQualified(TEST_FILE_PATH);
+    FSDataOutputStream os = fs.create(path);
+    os.write(1);
+    os.hsync();
+    // Delete the blob so that Azure call will fail.
+    fs.delete(path, false);
+    os.write(2);
+    LambdaTestUtils.intercept(IOException.class,
+        "The specified blob does not exist", () -> {
+          os.hsync();
+        });
+    LambdaTestUtils.intercept(IOException.class,
+        "The specified blob does not exist", () -> {
+          os.close();
+        });
+  }
+}