HBASE-14054 Acknowledged writes may get lost if regionserver clock is set backwards

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

@@ -3288,13 +3288,16 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
         boolean valueIsNull = comparator.getValue() == null ||
           comparator.getValue().length == 0;
         boolean matches = false;
+        long cellTs = 0;
         if (result.size() == 0 && valueIsNull) {
           matches = true;
         } else if (result.size() > 0 && result.get(0).getValueLength() == 0 &&
             valueIsNull) {
           matches = true;
+          cellTs = result.get(0).getTimestamp();
         } else if (result.size() == 1 && !valueIsNull) {
           Cell kv = result.get(0);
+          cellTs = kv.getTimestamp();
           int compareResult = CellComparator.compareValue(kv, comparator);
           switch (compareOp) {
           case LESS:
@@ -3321,6 +3324,20 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
         }
         //If matches put the new put or delete the new delete
         if (matches) {
+          // We have acquired the row lock already. If the system clock is NOT monotonically
+          // non-decreasing (see HBASE-14070) we should make sure that the mutation has a
+          // larger timestamp than what was observed via Get. doBatchMutate already does this, but
+          // there is no way to pass the cellTs. See HBASE-14054.
+          long now = EnvironmentEdgeManager.currentTime();
+          long ts = Math.max(now, cellTs); // ensure write is not eclipsed
+          byte[] byteTs = Bytes.toBytes(ts);
+
+          if (w instanceof Put) {
+            updateCellTimestamps(w.getFamilyCellMap().values(), byteTs);
+          }
+          // else delete is not needed since it already does a second get, and sets the timestamp
+          // from get (see prepareDeleteTimestamps).
+
           // All edits for the given row (across all column families) must
           // happen atomically.
           doBatchMutate(w);
@@ -3367,13 +3384,16 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
         boolean valueIsNull = comparator.getValue() == null ||
             comparator.getValue().length == 0;
         boolean matches = false;
+        long cellTs = 0;
         if (result.size() == 0 && valueIsNull) {
           matches = true;
         } else if (result.size() > 0 && result.get(0).getValueLength() == 0 &&
             valueIsNull) {
           matches = true;
+          cellTs = result.get(0).getTimestamp();
         } else if (result.size() == 1 && !valueIsNull) {
           Cell kv = result.get(0);
+          cellTs = kv.getTimestamp();
           int compareResult = CellComparator.compareValue(kv, comparator);
           switch (compareOp) {
           case LESS:
@@ -3400,6 +3420,22 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
         }
         //If matches put the new put or delete the new delete
         if (matches) {
+          // We have acquired the row lock already. If the system clock is NOT monotonically
+          // non-decreasing (see HBASE-14070) we should make sure that the mutation has a
+          // larger timestamp than what was observed via Get. doBatchMutate already does this, but
+          // there is no way to pass the cellTs. See HBASE-14054.
+          long now = EnvironmentEdgeManager.currentTime();
+          long ts = Math.max(now, cellTs); // ensure write is not eclipsed
+          byte[] byteTs = Bytes.toBytes(ts);
+
+          for (Mutation w : rm.getMutations()) {
+            if (w instanceof Put) {
+              updateCellTimestamps(w.getFamilyCellMap().values(), byteTs);
+            }
+            // else delete is not needed since it already does a second get, and sets the timestamp
+            // from get (see prepareDeleteTimestamps).
+          }
+
           // All edits for the given row (across all column families) must
           // happen atomically.
           mutateRow(rm);

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

@@ -102,6 +102,7 @@ import org.apache.hadoop.hbase.client.Get;
 import org.apache.hadoop.hbase.client.Increment;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.client.RowMutations;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.Table;
 import org.apache.hadoop.hbase.exceptions.FailedSanityCheckException;
@@ -145,6 +146,7 @@ import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManagerTestHelper;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.IncrementingEnvironmentEdge;
+import org.apache.hadoop.hbase.util.ManualEnvironmentEdge;
 import org.apache.hadoop.hbase.util.PairOfSameType;
 import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.hbase.wal.DefaultWALProvider;
@@ -6240,6 +6242,125 @@ public class TestHRegion {
     }
   }
 
+  @Test
+  public void testIncrementTimestampsAreMonotonic() throws IOException {
+    HRegion region = initHRegion(tableName, name.getMethodName(), CONF, fam1);
+    ManualEnvironmentEdge edge = new ManualEnvironmentEdge();
+    EnvironmentEdgeManager.injectEdge(edge);
+
+    edge.setValue(10);
+    Increment inc = new Increment(row);
+    inc.setDurability(Durability.SKIP_WAL);
+    inc.addColumn(fam1, qual1, 1L);
+    region.increment(inc);
+
+    Result result = region.get(new Get(row));
+    Cell c = result.getColumnLatestCell(fam1, qual1);
+    assertNotNull(c);
+    assertEquals(c.getTimestamp(), 10L);
+
+    edge.setValue(1); // clock goes back
+    region.increment(inc);
+    result = region.get(new Get(row));
+    c = result.getColumnLatestCell(fam1, qual1);
+    assertEquals(c.getTimestamp(), 10L);
+    assertEquals(Bytes.toLong(c.getValueArray(), c.getValueOffset(), c.getValueLength()), 2L);
+  }
+
+  @Test
+  public void testAppendTimestampsAreMonotonic() throws IOException {
+    HRegion region = initHRegion(tableName, name.getMethodName(), CONF, fam1);
+    ManualEnvironmentEdge edge = new ManualEnvironmentEdge();
+    EnvironmentEdgeManager.injectEdge(edge);
+
+    edge.setValue(10);
+    Append a = new Append(row);
+    a.setDurability(Durability.SKIP_WAL);
+    a.add(fam1, qual1, qual1);
+    region.append(a);
+
+    Result result = region.get(new Get(row));
+    Cell c = result.getColumnLatestCell(fam1, qual1);
+    assertNotNull(c);
+    assertEquals(c.getTimestamp(), 10L);
+
+    edge.setValue(1); // clock goes back
+    region.append(a);
+    result = region.get(new Get(row));
+    c = result.getColumnLatestCell(fam1, qual1);
+    assertEquals(c.getTimestamp(), 10L);
+
+    byte[] expected = new byte[qual1.length*2];
+    System.arraycopy(qual1, 0, expected, 0, qual1.length);
+    System.arraycopy(qual1, 0, expected, qual1.length, qual1.length);
+
+    assertTrue(Bytes.equals(c.getValueArray(), c.getValueOffset(), c.getValueLength(),
+      expected, 0, expected.length));
+  }
+
+  @Test
+  public void testCheckAndMutateTimestampsAreMonotonic() throws IOException {
+    HRegion region = initHRegion(tableName, name.getMethodName(), CONF, fam1);
+    ManualEnvironmentEdge edge = new ManualEnvironmentEdge();
+    EnvironmentEdgeManager.injectEdge(edge);
+
+    edge.setValue(10);
+    Put p = new Put(row);
+    p.setDurability(Durability.SKIP_WAL);
+    p.addColumn(fam1, qual1, qual1);
+    region.put(p);
+
+    Result result = region.get(new Get(row));
+    Cell c = result.getColumnLatestCell(fam1, qual1);
+    assertNotNull(c);
+    assertEquals(c.getTimestamp(), 10L);
+
+    edge.setValue(1); // clock goes back
+    p = new Put(row);
+    p.setDurability(Durability.SKIP_WAL);
+    p.addColumn(fam1, qual1, qual2);
+    region.checkAndMutate(row, fam1, qual1, CompareOp.EQUAL, new BinaryComparator(qual1), p, false);
+    result = region.get(new Get(row));
+    c = result.getColumnLatestCell(fam1, qual1);
+    assertEquals(c.getTimestamp(), 10L);
+
+    assertTrue(Bytes.equals(c.getValueArray(), c.getValueOffset(), c.getValueLength(),
+      qual2, 0, qual2.length));
+  }
+
+  @Test
+  public void testCheckAndRowMutateTimestampsAreMonotonic() throws IOException {
+    HRegion region = initHRegion(tableName, name.getMethodName(), CONF, fam1);
+    ManualEnvironmentEdge edge = new ManualEnvironmentEdge();
+    EnvironmentEdgeManager.injectEdge(edge);
+
+    edge.setValue(10);
+    Put p = new Put(row);
+    p.setDurability(Durability.SKIP_WAL);
+    p.addColumn(fam1, qual1, qual1);
+    region.put(p);
+
+    Result result = region.get(new Get(row));
+    Cell c = result.getColumnLatestCell(fam1, qual1);
+    assertNotNull(c);
+    assertEquals(c.getTimestamp(), 10L);
+
+    edge.setValue(1); // clock goes back
+    p = new Put(row);
+    p.setDurability(Durability.SKIP_WAL);
+    p.addColumn(fam1, qual1, qual2);
+    RowMutations rm = new RowMutations(row);
+    rm.add(p);
+    region.checkAndRowMutate(row, fam1, qual1, CompareOp.EQUAL, new BinaryComparator(qual1),
+      rm, false);
+    result = region.get(new Get(row));
+    c = result.getColumnLatestCell(fam1, qual1);
+    assertEquals(c.getTimestamp(), 10L);
+
+    assertTrue(Bytes.equals(c.getValueArray(), c.getValueOffset(), c.getValueLength(),
+      qual2, 0, qual2.length));
+  }
+
   static HRegion initHRegion(TableName tableName, String callingMethod,
       byte[]... families) throws IOException {
     return initHRegion(tableName, callingMethod, HBaseConfiguration.create(),