Hadoop 16857. ABFS: Stop CustomTokenProvider retry logic to depend on AbfsRestOp retry policy

Contributed by Sneha Vijayarajan

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

@@ -110,6 +110,11 @@ public class AbfsConfiguration{
       DefaultValue = DEFAULT_MAX_RETRY_ATTEMPTS)
   private int maxIoRetries;
 
+  @IntegerConfigurationValidatorAnnotation(ConfigurationKey = AZURE_CUSTOM_TOKEN_FETCH_RETRY_COUNT,
+      MinValue = 0,
+      DefaultValue = DEFAULT_CUSTOM_TOKEN_FETCH_RETRY_COUNT)
+  private int customTokenFetchRetryCount;
+
   @LongConfigurationValidatorAnnotation(ConfigurationKey = AZURE_BLOCK_SIZE_PROPERTY_NAME,
       MinValue = 0,
       MaxValue = MAX_AZURE_BLOCK_SIZE,
@@ -425,6 +430,10 @@ public int getMaxIoRetries() {
     return this.maxIoRetries;
   }
 
+  public int getCustomTokenFetchRetryCount() {
+    return this.customTokenFetchRetryCount;
+  }
+
   public long getAzureBlockSize() {
     return this.azureBlockSize;
   }
@@ -597,7 +606,7 @@ public AccessTokenProvider getTokenProvider() throws TokenAccessProviderExceptio
         LOG.trace("Initializing {}", customTokenProviderClass.getName());
         azureTokenProvider.initialize(rawConfig, accountName);
         LOG.trace("{} init complete", customTokenProviderClass.getName());
-        return new CustomTokenProviderAdapter(azureTokenProvider);
+        return new CustomTokenProviderAdapter(azureTokenProvider, getCustomTokenFetchRetryCount());
       } catch(IllegalArgumentException e) {
         throw e;
       } catch (Exception e) {
@@ -732,6 +741,11 @@ void setListMaxResults(int listMaxResults) {
     this.listMaxResults = listMaxResults;
   }
 
+  @VisibleForTesting
+  public void setMaxIoRetries(int maxIoRetries) {
+    this.maxIoRetries = maxIoRetries;
+  }
+
   private String getTrimmedPasswordString(String key, String defaultValue) throws IOException {
     String value = getPasswordString(key);
     if (StringUtils.isBlank(value)) {

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

@@ -36,6 +36,7 @@ public final class ConfigurationKeys {
   public static final String AZURE_MAX_BACKOFF_INTERVAL = "fs.azure.io.retry.max.backoff.interval";
   public static final String AZURE_BACKOFF_INTERVAL = "fs.azure.io.retry.backoff.interval";
   public static final String AZURE_MAX_IO_RETRIES = "fs.azure.io.retry.max.retries";
+  public static final String AZURE_CUSTOM_TOKEN_FETCH_RETRY_COUNT = "fs.azure.custom.token.fetch.retry.count";
 
   // Read and write buffer sizes defined by the user
   public static final String AZURE_WRITE_BUFFER_SIZE = "fs.azure.write.request.size";

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

@@ -37,6 +37,7 @@ public final class FileSystemConfigurations {
   public static final int DEFAULT_MAX_BACKOFF_INTERVAL = 30 * 1000;  // 30s
   public static final int DEFAULT_BACKOFF_INTERVAL = 3 * 1000;  // 3s
   public static final int DEFAULT_MAX_RETRY_ATTEMPTS = 30;
+  public static final int DEFAULT_CUSTOM_TOKEN_FETCH_RETRY_COUNT = 3;
 
   private static final int ONE_KB = 1024;
   private static final int ONE_MB = ONE_KB * ONE_KB;

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/oauth2/AzureADAuthenticator.java

@@ -230,12 +230,23 @@ public String getMessage() {
       final StringBuilder sb = new StringBuilder();
       sb.append("HTTP Error ");
       sb.append(httpErrorCode);
-      sb.append("; url='").append(url).append('\'');
-      sb.append(' ');
+      if (!url.isEmpty()) {
+        sb.append("; url='").append(url).append('\'').append(' ');
+      }
+
       sb.append(super.getMessage());
-      sb.append("; requestId='").append(requestId).append('\'');
-      sb.append("; contentType='").append(contentType).append('\'');
-      sb.append("; response '").append(body).append('\'');
+      if (!requestId.isEmpty()) {
+        sb.append("; requestId='").append(requestId).append('\'');
+      }
+
+      if (!contentType.isEmpty()) {
+        sb.append("; contentType='").append(contentType).append('\'');
+      }
+
+      if (!body.isEmpty()) {
+        sb.append("; response '").append(body).append('\'');
+      }
+
       return sb.toString();
     }
   }

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/oauth2/CustomTokenProviderAdapter.java

@@ -30,6 +30,7 @@
 import org.apache.hadoop.fs.azurebfs.extensions.BoundDTExtension;
 import org.apache.hadoop.fs.azurebfs.extensions.CustomTokenProviderAdaptee;
 import org.apache.hadoop.fs.azurebfs.extensions.ExtensionHelper;
+import org.apache.hadoop.fs.azurebfs.oauth2.AzureADAuthenticator.HttpException;
 
 /**
  * Provides tokens based on custom implementation, following the Adapter Design
@@ -38,6 +39,7 @@
 public final class CustomTokenProviderAdapter extends AccessTokenProvider
   implements BoundDTExtension {
 
+  private final int fetchTokenRetryCount;
   private CustomTokenProviderAdaptee adaptee;
   private static final Logger LOG = LoggerFactory.getLogger(AccessTokenProvider.class);
 
@@ -45,17 +47,57 @@ public final class CustomTokenProviderAdapter extends AccessTokenProvider
    * Constructs a token provider based on the custom token provider.
    *
    * @param adaptee the custom token provider
+   * @param customTokenFetchRetryCount max retry count for customTokenFetch
    */
-  public CustomTokenProviderAdapter(CustomTokenProviderAdaptee adaptee) {
+  public CustomTokenProviderAdapter(CustomTokenProviderAdaptee adaptee, int customTokenFetchRetryCount) {
     Preconditions.checkNotNull(adaptee, "adaptee");
     this.adaptee = adaptee;
+    fetchTokenRetryCount = customTokenFetchRetryCount;
   }
 
   protected AzureADToken refreshToken() throws IOException {
     LOG.debug("AADToken: refreshing custom based token");
 
     AzureADToken azureADToken = new AzureADToken();
-    azureADToken.setAccessToken(adaptee.getAccessToken());
+
+    String accessToken = null;
+
+    Exception ex;
+    boolean succeeded = false;
+    // Custom token providers should have their own retry policies,
+    // Providing a linear retry option for the the retry count
+    // mentioned in config "fs.azure.custom.token.fetch.retry.count"
+    int retryCount = fetchTokenRetryCount;
+    do {
+      ex = null;
+      try {
+        accessToken = adaptee.getAccessToken();
+        LOG.trace("CustomTokenProvider Access token fetch was successful with retry count {}",
+            (fetchTokenRetryCount - retryCount));
+      } catch (Exception e) {
+        LOG.debug("CustomTokenProvider Access token fetch failed with retry count {}",
+            (fetchTokenRetryCount - retryCount));
+        ex = e;
+      }
+
+      succeeded = (ex == null);
+      retryCount--;
+    } while (!succeeded && (retryCount) >= 0);
+
+    if (!succeeded) {
+      HttpException httpEx = new HttpException(
+          -1,
+          "",
+          String.format("CustomTokenProvider getAccessToken threw %s : %s",
+              ex.getClass().getTypeName(), ex.getMessage()),
+          "",
+          "",
+          ""
+      );
+      throw httpEx;
+    }
+
+    azureADToken.setAccessToken(accessToken);
     azureADToken.setExpiry(adaptee.getExpiryTime());
 
     return azureADToken;

hadoop-tools/hadoop-azure/src/site/markdown/abfs.md

@@ -539,6 +539,8 @@ token when its `getAccessToken()` method is invoked.
 The declared class must implement `org.apache.hadoop.fs.azurebfs.extensions.CustomTokenProviderAdaptee`
 and optionally `org.apache.hadoop.fs.azurebfs.extensions.BoundDTExtension`.
 
+The declared class also holds responsibility to implement retry logic while fetching access tokens.
+
 ## <a name="technical"></a> Technical notes
 
 ### <a name="proxy"></a> Proxy setup

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

@@ -79,12 +79,13 @@ public void testAbfsRestOperationExceptionFormat() throws IOException {
   }
 
   @Test
-  public void testRequestRetryConfig() throws Exception {
-    testRetryLogic(0);
-    testRetryLogic(3);
+  public void testCustomTokenFetchRetryCount() throws Exception {
+    testWithDifferentCustomTokenFetchRetry(0);
+    testWithDifferentCustomTokenFetchRetry(3);
+    testWithDifferentCustomTokenFetchRetry(5);
   }
 
-  public void testRetryLogic(int numOfRetries) throws Exception {
+  public void testWithDifferentCustomTokenFetchRetry(int numOfRetries) throws Exception {
     AzureBlobFileSystem fs = this.getFileSystem();
 
     Configuration config = new Configuration(this.getRawConfiguration());
@@ -93,7 +94,7 @@ public void testRetryLogic(int numOfRetries) throws Exception {
     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));
+    config.set("fs.azure.custom.token.fetch.retry.count", Integer.toString(numOfRetries));
     // Stop filesystem creation as it will lead to calls to store.
     config.set("fs.azure.createRemoteFileSystemDuringInitialization", "false");
 
@@ -110,7 +111,7 @@ public void testRetryLogic(int numOfRetries) throws Exception {
     // 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
+            + ") done, does not match with fs.azure.custom.token.fetch.retry.count configured (" + numOfRetries
             + ")", RetryTestTokenProvider.reTryCount == numOfRetries);
   }
 }

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

@@ -0,0 +1,88 @@
+/**
+ * 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.services;
+
+import java.util.Random;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.apache.hadoop.conf.Configuration;
+
+import org.apache.hadoop.fs.azurebfs.AbfsConfiguration;
+import org.apache.hadoop.fs.azurebfs.AbstractAbfsIntegrationTest;
+
+/**
+ * Unit test TestExponentialRetryPolicy.
+ */
+public class TestExponentialRetryPolicy extends AbstractAbfsIntegrationTest {
+
+  private final int maxRetryCount = 30;
+  private final int noRetryCount = 0;
+  private final int retryCount = new Random().nextInt(maxRetryCount);
+  private final int retryCountBeyondMax = maxRetryCount + 1;
+
+
+  public TestExponentialRetryPolicy() throws Exception {
+    super();
+  }
+
+  @Test
+  public void testDifferentMaxIORetryCount() throws Exception {
+    AbfsConfiguration abfsConfig = getAbfsConfig();
+    abfsConfig.setMaxIoRetries(noRetryCount);
+    testMaxIOConfig(abfsConfig);
+    abfsConfig.setMaxIoRetries(retryCount);
+    testMaxIOConfig(abfsConfig);
+    abfsConfig.setMaxIoRetries(retryCountBeyondMax);
+    testMaxIOConfig(abfsConfig);
+  }
+
+  @Test
+  public void testDefaultMaxIORetryCount() throws Exception {
+    AbfsConfiguration abfsConfig = getAbfsConfig();
+    Assert.assertTrue(
+        String.format("default maxIORetry count is %s.", maxRetryCount),
+        abfsConfig.getMaxIoRetries() == maxRetryCount);
+    testMaxIOConfig(abfsConfig);
+  }
+
+  private AbfsConfiguration getAbfsConfig() throws Exception {
+    Configuration
+        config = new Configuration(this.getRawConfiguration());
+    return new AbfsConfiguration(config, "dummyAccountName");
+  }
+
+  private void testMaxIOConfig(AbfsConfiguration abfsConfig) {
+    ExponentialRetryPolicy retryPolicy = new ExponentialRetryPolicy(
+        abfsConfig.getMaxIoRetries());
+    int localRetryCount = 0;
+
+    while (localRetryCount < abfsConfig.getMaxIoRetries()) {
+      Assert.assertTrue(
+          "Retry should be allowed when retryCount less than max count configured.",
+          retryPolicy.shouldRetry(localRetryCount, -1));
+      localRetryCount++;
+    }
+
+    Assert.assertTrue(
+        "When all retries are exhausted, the retryCount will be same as max configured",
+        localRetryCount == abfsConfig.getMaxIoRetries());
+  }
+}