HDFS-17631. Fix RedundantEditLogInputStream.nextOp() state error when EditLogInputStream.skipUntil() throw IOException (#7066). Contributed by liuguanghua.

Signed-off-by: He Xiaoqiao <hexiaoqiao@apache.org>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/RedundantEditLogInputStream.java

@@ -193,6 +193,8 @@ protected FSEditLogOp nextOp() throws IOException {
         } catch (IOException e) {
           prevException = e;
           state = State.STREAM_FAILED;
+          LOG.warn("Got error skipUntil edit log input stream {}.", streams[curIdx].getName());
+          break;
         }
         state = State.OK;
         break;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestRedundantEditLogInputStream.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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.hdfs.server.namenode;
+
+import java.io.IOException;
+import java.util.ArrayList;
+
+import org.junit.Test;
+
+import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.MkdirOp;
+import org.apache.hadoop.test.GenericTestUtils.LogCapturer;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class TestRedundantEditLogInputStream {
+  private static final String FAKE_EDIT_STREAM_NAME = "FAKE_STREAM";
+
+  @Test
+  public void testNextOp() throws IOException {
+    EditLogInputStream fakeStream1 = mock(EditLogInputStream.class);
+    EditLogInputStream fakeStream2 = mock(EditLogInputStream.class);
+    ArrayList<EditLogInputStream> list = new ArrayList();
+    list.add(fakeStream1);
+    list.add(fakeStream2);
+    for (int i = 0; i < list.size(); i++) {
+      EditLogInputStream stream = list.get(i);
+      when(stream.getName()).thenReturn(FAKE_EDIT_STREAM_NAME + i);
+      when(stream.getFirstTxId()).thenReturn(1L);
+      when(stream.getLastTxId()).thenReturn(2L);
+      when(stream.length()).thenReturn(1L);
+    }
+    when(fakeStream1.skipUntil(1)).thenThrow(new IOException("skipUntil failed."));
+    when(fakeStream2.skipUntil(1)).thenReturn(true);
+    FSEditLogOp op = new MkdirOp();
+    op.setTransactionId(100);
+    when(fakeStream2.readOp()).thenReturn(op);
+
+    LogCapturer capture = LogCapturer.captureLogs(RedundantEditLogInputStream.LOG);
+    RedundantEditLogInputStream redundantEditLogInputStream =
+        new RedundantEditLogInputStream(list, 1);
+
+    FSEditLogOp returnOp = redundantEditLogInputStream.nextOp();
+    String log = capture.getOutput();
+    assertTrue(log.contains("Got error skipUntil edit log input stream FAKE_STREAM0"));
+    assertTrue(log.contains("Got error reading edit log input stream FAKE_STREAM0; "
+        + "failing over to edit log FAKE_STREAM1"));
+    assertEquals(op, returnOp);
+  }
+}