HBASE-13662 RSRpcService.scan() throws an OutOfOrderScannerNext if the scan has a retriable failure

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RSRpcServices.java

@@ -238,14 +238,26 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
    * Holder class which holds the RegionScanner and nextCallSeq together.
    */
   private static class RegionScannerHolder {
+    private AtomicLong nextCallSeq = new AtomicLong(0);
     private RegionScanner s;
-    private long nextCallSeq = 0L;
     private Region r;
 
     public RegionScannerHolder(RegionScanner s, Region r) {
       this.s = s;
       this.r = r;
     }
+
+    private long getNextCallSeq() {
+      return nextCallSeq.get();
+    }
+
+    private void incNextCallSeq() {
+      nextCallSeq.incrementAndGet();
+    }
+
+    private void rollbackNextCallSeq() {
+      nextCallSeq.decrementAndGet();
+    }
   }
 
   /**
@@ -902,7 +914,7 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
     String scannerIdString = Long.toString(scannerId);
     RegionScannerHolder scannerHolder = scanners.get(scannerIdString);
     if (scannerHolder != null) {
-      return scannerHolder.nextCallSeq;
+      return scannerHolder.getNextCallSeq();
     }
     return 0L;
   }
@@ -2225,13 +2237,14 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
             rsh = scanners.get(scannerName);
           }
           if (rsh != null) {
-            if (request.getNextCallSeq() != rsh.nextCallSeq) {
+            if (request.getNextCallSeq() != rsh.getNextCallSeq()) {
-              throw new OutOfOrderScannerNextException("Expected nextCallSeq: " + rsh.nextCallSeq
+              throw new OutOfOrderScannerNextException(
+                "Expected nextCallSeq: " + rsh.getNextCallSeq()
                 + " But the nextCallSeq got from client: " + request.getNextCallSeq() +
                 "; request=" + TextFormat.shortDebugString(request));
             }
             // Increment the nextCallSeq value which is the next expected from client.
-            rsh.nextCallSeq++;
+            rsh.incNextCallSeq();
           }
         }
         try {
@@ -2411,6 +2424,14 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
           } else {
             addResults(builder, results, controller, RegionReplicaUtil.isDefaultReplica(region.getRegionInfo()));
           }
+        } catch (IOException e) {
+          // if we have an exception on scanner next and we are using the callSeq
+          // we should rollback because the client will retry with the same callSeq
+          // and get an OutOfOrderScannerNextException if we don't do so.
+          if (rsh != null && request.hasNextCallSeq()) {
+            rsh.rollbackNextCallSeq();
+          }
+          throw e;
         } finally {
           // We're done. On way out re-add the above removed lease.
           // Adding resets expiration time on lease.

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestScannerRetriableFailure.java

@@ -0,0 +1,171 @@
+/**
+ * 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.hbase.regionserver;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.Scan;
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.client.ResultScanner;
+import org.apache.hadoop.hbase.client.Durability;
+import org.apache.hadoop.hbase.client.Put;
+import org.apache.hadoop.hbase.client.Table;
+import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
+import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
+import org.apache.hadoop.hbase.coprocessor.ObserverContext;
+import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
+import org.apache.hadoop.hbase.testclassification.RegionServerTests;
+import org.apache.hadoop.hbase.testclassification.LargeTests;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hbase.util.FSVisitor;
+import org.apache.hadoop.hbase.util.TestTableName;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+@Category({RegionServerTests.class, LargeTests.class})
+public class TestScannerRetriableFailure {
+  private static final Log LOG = LogFactory.getLog(TestScannerRetriableFailure.class);
+
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  private static final String FAMILY_NAME_STR = "f";
+  private static final byte[] FAMILY_NAME = Bytes.toBytes(FAMILY_NAME_STR);
+
+  @Rule public TestTableName TEST_TABLE = new TestTableName();
+
+  public static class FaultyScannerObserver extends BaseRegionObserver {
+    private int faults = 0;
+
+    @Override
+    public boolean preScannerNext(final ObserverContext<RegionCoprocessorEnvironment> e,
+        final InternalScanner s, final List<Result> results,
+        final int limit, final boolean hasMore) throws IOException {
+      final TableName tableName = e.getEnvironment().getRegionInfo().getTable();
+      if (!tableName.isSystemTable() && (faults++ % 2) == 0) {
+        LOG.debug(" Injecting fault in table=" + tableName + " scanner");
+        throw new IOException("injected fault");
+      }
+      return hasMore;
+    }
+  }
+
+  private static void setupConf(Configuration conf) {
+    conf.setLong("hbase.hstore.compaction.min", 20);
+    conf.setLong("hbase.hstore.compaction.max", 39);
+    conf.setLong("hbase.hstore.blockingStoreFiles", 40);
+
+    conf.set(CoprocessorHost.REGION_COPROCESSOR_CONF_KEY, FaultyScannerObserver.class.getName());
+  }
+
+  @BeforeClass
+  public static void setup() throws Exception {
+    setupConf(UTIL.getConfiguration());
+    UTIL.startMiniCluster(1);
+  }
+
+  @AfterClass
+  public static void tearDown() throws Exception {
+    try {
+      UTIL.shutdownMiniCluster();
+    } catch (Exception e) {
+      LOG.warn("failure shutting down cluster", e);
+    }
+  }
+
+  @Test(timeout=180000)
+  public void testFaultyScanner() throws Exception {
+    TableName tableName = TEST_TABLE.getTableName();
+    Table table = UTIL.createTable(tableName, FAMILY_NAME);
+    try {
+      final int NUM_ROWS = 100;
+      loadTable(table, NUM_ROWS);
+      checkTableRows(table, NUM_ROWS);
+    } finally {
+      table.close();
+    }
+  }
+
+  // ==========================================================================
+  //  Helpers
+  // ==========================================================================
+  private FileSystem getFileSystem() {
+    return UTIL.getHBaseCluster().getMaster().getMasterFileSystem().getFileSystem();
+  }
+
+  private Path getRootDir() {
+    return UTIL.getHBaseCluster().getMaster().getMasterFileSystem().getRootDir();
+  }
+
+  public void loadTable(final Table table, int numRows) throws IOException {
+    List<Put> puts = new ArrayList<Put>(numRows);
+    for (int i = 0; i < numRows; ++i) {
+      byte[] row = Bytes.toBytes(String.format("%09d", i));
+      Put put = new Put(row);
+      put.setDurability(Durability.SKIP_WAL);
+      put.add(FAMILY_NAME, null, row);
+      table.put(put);
+    }
+  }
+
+  private void checkTableRows(final Table table, int numRows) throws Exception {
+    Scan scan = new Scan();
+    scan.setCaching(1);
+    scan.setCacheBlocks(false);
+    ResultScanner scanner = table.getScanner(scan);
+    try {
+      int count = 0;
+      for (int i = 0; i < numRows; ++i) {
+        byte[] row = Bytes.toBytes(String.format("%09d", i));
+        Result result = scanner.next();
+        assertTrue(result != null);
+        assertTrue(Bytes.equals(row, result.getRow()));
+        count++;
+      }
+
+      while (true) {
+        Result result = scanner.next();
+        if (result == null) break;
+        count++;
+      }
+      assertEquals(numRows, count);
+    } finally {
+      scanner.close();
+    }
+  }
+}