HDDS-4429. Create unit test for SimpleContainerDownloader.

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/replication/SimpleContainerDownloader.java

@@ -32,6 +32,7 @@
 import org.apache.hadoop.hdds.security.x509.SecurityConfig;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
 
+import com.google.common.annotations.VisibleForTesting;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -74,24 +75,16 @@ public CompletableFuture<Path> getContainerDataFromReplicas(long containerId,
     for (DatanodeDetails datanode : sourceDatanodes) {
       try {
         if (result == null) {
-          GrpcReplicationClient grpcReplicationClient =
-              new GrpcReplicationClient(datanode.getIpAddress(),
-                  datanode.getPort(Name.STANDALONE).getValue(),
-                  workingDirectory, securityConfig, caCert);
-          result = grpcReplicationClient.download(containerId);
+          result = downloadContainer(containerId, datanode);
         } else {
           result = result.thenApply(CompletableFuture::completedFuture)
               .exceptionally(t -> {
                 LOG.error("Error on replicating container: " + containerId, t);
                 try {
-                  GrpcReplicationClient grpcReplicationClient =
-                      new GrpcReplicationClient(datanode.getIpAddress(),
-                          datanode.getPort(Name.STANDALONE).getValue(),
-                          workingDirectory, securityConfig, caCert);
-                  return grpcReplicationClient.download(containerId);
+                  return downloadContainer(containerId, datanode);
                 } catch (IOException e) {
                   LOG.error("Error on replicating container: " + containerId,
-                      t);
+                      e);
                   return null;
                 }
               }).thenCompose(Function.identity());
@@ -107,6 +100,20 @@ public CompletableFuture<Path> getContainerDataFromReplicas(long containerId,
 
   }
 
+  @VisibleForTesting
+  protected CompletableFuture<Path> downloadContainer(
+      long containerId,
+      DatanodeDetails datanode
+  ) throws IOException {
+    CompletableFuture<Path> result;
+    GrpcReplicationClient grpcReplicationClient =
+        new GrpcReplicationClient(datanode.getIpAddress(),
+            datanode.getPort(Name.STANDALONE).getValue(),
+            workingDirectory, securityConfig, caCert);
+    result = grpcReplicationClient.download(containerId);
+    return result;
+  }
+
   @Override
   public void close() {
     // noop

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/replication/TestSimpleContainerDownloader.java

@@ -0,0 +1,150 @@
+/*
+ * 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.ozone.container.replication;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.hadoop.hdds.conf.ConfigurationSource;
+import org.apache.hadoop.hdds.conf.OzoneConfiguration;
+import org.apache.hadoop.hdds.protocol.DatanodeDetails;
+import org.apache.hadoop.hdds.protocol.MockDatanodeDetails;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test SimpleContainerDownloader.
+ */
+public class TestSimpleContainerDownloader {
+
+  @Test
+  public void testGetContainerDataFromReplicasHappyPath() throws Exception {
+
+    //GIVEN
+    List<DatanodeDetails> datanodes = createDatanodes();
+
+    SimpleContainerDownloader downloader =
+        createDownloaderWithPredefinedFailures(true);
+
+    //WHEN
+    final Path result =
+        downloader.getContainerDataFromReplicas(1L, datanodes)
+            .get(1L, TimeUnit.SECONDS);
+
+    //THEN
+    Assert.assertEquals(datanodes.get(0).getUuidString(), result.toString());
+  }
+
+  @Test
+  public void testGetContainerDataFromReplicasDirectFailure()
+      throws Exception {
+
+    //GIVEN
+    List<DatanodeDetails> datanodes = createDatanodes();
+
+    SimpleContainerDownloader downloader =
+        createDownloaderWithPredefinedFailures(true, datanodes.get(0));
+
+    //WHEN
+    final Path result =
+        downloader.getContainerDataFromReplicas(1L, datanodes)
+            .get(1L, TimeUnit.SECONDS);
+
+    //THEN
+    //first datanode is failed, second worked
+    Assert.assertEquals(datanodes.get(1).getUuidString(), result.toString());
+  }
+
+  @Test
+  public void testGetContainerDataFromReplicasAsyncFailure() throws Exception {
+
+    //GIVEN
+    List<DatanodeDetails> datanodes = createDatanodes();
+
+    SimpleContainerDownloader downloader =
+        createDownloaderWithPredefinedFailures(false, datanodes.get(0));
+
+    //WHEN
+    final Path result =
+        downloader.getContainerDataFromReplicas(1L, datanodes)
+            .get(1L, TimeUnit.SECONDS);
+
+    //THEN
+    //first datanode is failed, second worked
+    Assert.assertEquals(datanodes.get(1).getUuidString(), result.toString());
+  }
+
+  /**
+   * Creates downloader which fails with datanodes in the arguments.
+   *
+   * @param directException if false the exception will be wrapped in the
+   *                        returning future.
+   */
+  private SimpleContainerDownloader createDownloaderWithPredefinedFailures(
+      boolean directException,
+      DatanodeDetails... failedDatanodes
+  ) {
+
+    ConfigurationSource conf = new OzoneConfiguration();
+
+    final List<DatanodeDetails> datanodes =
+        Arrays.asList(failedDatanodes);
+
+    return new SimpleContainerDownloader(conf, null) {
+
+      @Override
+      protected CompletableFuture<Path> downloadContainer(
+          long containerId,
+          DatanodeDetails datanode
+      ) throws IOException {
+
+        if (datanodes.contains(datanode)) {
+          if (directException) {
+            throw new IOException("Unavailable datanode");
+          } else {
+            return CompletableFuture.supplyAsync(() -> {
+              throw new RuntimeException("Unavailable datanode");
+            });
+          }
+        } else {
+
+          //path includes the dn id to make it possible to assert.
+          return CompletableFuture.completedFuture(
+              Paths.get(datanode.getUuidString()));
+        }
+
+      }
+    };
+  }
+
+  private List<DatanodeDetails> createDatanodes() {
+    List<DatanodeDetails> datanodes = new ArrayList<>();
+    datanodes.add(MockDatanodeDetails.randomDatanodeDetails());
+    datanodes.add(MockDatanodeDetails.randomDatanodeDetails());
+    datanodes.add(MockDatanodeDetails.randomDatanodeDetails());
+    return datanodes;
+  }
+}