HADOOP-16778. ABFS: Backport HADOOP-16660 ABFS: Make RetryCount in ExponentialRetryPolicy Configurable to Branch-2.

Contributed by Sneha Vijayarajan.

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

@@ -938,7 +938,9 @@ private void initializeClient(URI uri, String fileSystemName, String accountName
       tokenProvider = abfsConfiguration.getTokenProvider();
     }
 
-    this.client =  new AbfsClient(baseUrl, creds, abfsConfiguration, new ExponentialRetryPolicy(), tokenProvider);
+    this.client = new AbfsClient(baseUrl, creds, abfsConfiguration,
+        new ExponentialRetryPolicy(abfsConfiguration.getMaxIoRetries()),
+        tokenProvider);
   }
 
   private String getOctalNotation(FsPermission fsPermission) {

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsRestOperation.java

@@ -122,8 +122,11 @@ public AbfsHttpOperation getResult() {
    */
   void execute() throws AzureBlobFileSystemException {
     int retryCount = 0;
+    LOG.debug("First execution of REST operation - {}", operationType);
     while (!executeHttpOperation(retryCount++)) {
       try {
+        LOG.debug("Retrying REST operation {}. RetryCount = {}",
+            operationType, retryCount);
         Thread.sleep(client.getRetryPolicy().getRetryInterval(retryCount));
       } catch (InterruptedException ex) {
         Thread.currentThread().interrupt();

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/ExponentialRetryPolicy.java

@@ -25,11 +25,6 @@
  * Retry policy used by AbfsClient.
  * */
 public class ExponentialRetryPolicy {
-  /**
-   * Represents the default number of retry attempts.
-   */
-  private static final int DEFAULT_CLIENT_RETRY_COUNT = 30;
-
   /**
    * Represents the default amount of time used when calculating a random delta in the exponential
    * delay between retries.
@@ -86,8 +81,10 @@ public class ExponentialRetryPolicy {
   /**
    * Initializes a new instance of the {@link ExponentialRetryPolicy} class.
    */
-  public ExponentialRetryPolicy() {
+  public ExponentialRetryPolicy(final int maxIoRetries) {
-    this(DEFAULT_CLIENT_RETRY_COUNT, DEFAULT_MIN_BACKOFF, DEFAULT_MAX_BACKOFF, DEFAULT_CLIENT_BACKOFF);
+
+    this(maxIoRetries, DEFAULT_MIN_BACKOFF, DEFAULT_MAX_BACKOFF,
+        DEFAULT_CLIENT_BACKOFF);
   }
 
   /**

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

@@ -20,12 +20,17 @@
 
 import java.io.IOException;
 
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.azurebfs.oauth2.RetryTestTokenProvider;
 import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 
 import org.junit.Assert;
 import org.junit.Test;
 
+import static org.apache.hadoop.test.LambdaTestUtils.intercept;
+
 /**
  * Verify the AbfsRestOperationException error message format.
  * */
@@ -72,4 +77,40 @@ public void testAbfsRestOperationExceptionFormat() throws IOException {
               && errorFields[5].contains("Time"));
     }
   }
+
+  @Test
+  public void testRequestRetryConfig() throws Exception {
+    testRetryLogic(0);
+    testRetryLogic(3);
+  }
+
+  public void testRetryLogic(int numOfRetries) throws Exception {
+    AzureBlobFileSystem fs = this.getFileSystem();
+
+    Configuration config = new Configuration(this.getRawConfiguration());
+    String accountName = config.get("fs.azure.abfs.account.name");
+    // Setup to configure custom token provider
+    config.set("fs.azure.account.auth.type." + accountName, "Custom");
+    config.set("fs.azure.account.oauth.provider.type." + accountName, "org.apache.hadoop.fs"
+        + ".azurebfs.oauth2.RetryTestTokenProvider");
+    config.set("fs.azure.io.retry.max.retries", Integer.toString(numOfRetries));
+    // Stop filesystem creation as it will lead to calls to store.
+    config.set("fs.azure.createRemoteFileSystemDuringInitialization", "false");
+
+    final AzureBlobFileSystem fs1 =
+        (AzureBlobFileSystem) FileSystem.newInstance(fs.getUri(),
+        config);
+    RetryTestTokenProvider.ResetStatusToFirstTokenFetch();
+    try {
+      fs1.getFileStatus(new Path("/"));
+    } catch (Exception ex) {
+      // Expected to fail as
+    }
+
+    // Number of retries done should be as configured
+    Assert.assertTrue(
+        "Number of token fetch retries (" + RetryTestTokenProvider.reTryCount
+            + ") done, does not match with max " + "retry count configured (" + numOfRetries
+            + ")", RetryTestTokenProvider.reTryCount == numOfRetries);
+  }
 }

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/oauth2/RetryTestTokenProvider.java

@@ -0,0 +1,67 @@
+/**
+ * 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.azurebfs.oauth2;
+
+import java.io.IOException;
+import java.util.Date;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.azurebfs.extensions.CustomTokenProviderAdaptee;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Test Token provider which should throw exception and trigger retries
+ */
+public class RetryTestTokenProvider implements CustomTokenProviderAdaptee {
+
+  // Need to track first token fetch otherwise will get counted as a retry too.
+  private static boolean isThisFirstTokenFetch = true;
+  public static int reTryCount = 0;
+
+  private static final Logger LOG = LoggerFactory
+      .getLogger(RetryTestTokenProvider.class);
+
+  @Override
+  public void initialize(Configuration configuration, String accountName)
+      throws IOException {
+
+  }
+
+  public static void ResetStatusToFirstTokenFetch() {
+    isThisFirstTokenFetch = true;
+    reTryCount = 0;
+  }
+
+  @Override
+  public String getAccessToken() throws IOException {
+    if (isThisFirstTokenFetch) {
+      isThisFirstTokenFetch = false;
+    } else {
+      reTryCount++;
+    }
+
+    LOG.debug("RetryTestTokenProvider: Throw an exception in fetching tokens");
+    throw new IOException("test exception");
+  }
+
+  @Override
+  public Date getExpiryTime() {
+    return new Date();
+  }
+}