diff --git a/hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSource.java b/hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSource.java
index c6dc731c823..a665571868d 100644
--- a/hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSource.java
+++ b/hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSource.java
@@ -62,6 +62,8 @@ public interface MetricsWALSource extends BaseSource {
   String LOW_REPLICA_ROLL_REQUESTED = "lowReplicaRollRequest";
   String LOW_REPLICA_ROLL_REQUESTED_DESC =
       "How many times a log roll was requested due to too few DN's in the write pipeline.";
+  String WRITTEN_BYTES = "writtenBytes";
+  String WRITTEN_BYTES_DESC = "Size (in bytes) of the data written to the WAL.";
 
   /**
    * Add the append size.
@@ -93,4 +95,8 @@ public interface MetricsWALSource extends BaseSource {
   void incrementLowReplicationLogRoll();
 
   long getSlowAppendCount();
+
+  void incrementWrittenBytes(long val);
+
+  long getWrittenBytes();
 }
diff --git a/hbase-hadoop2-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSourceImpl.java b/hbase-hadoop2-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSourceImpl.java
index 995e3343a79..9f9e09cd839 100644
--- a/hbase-hadoop2-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSourceImpl.java
+++ b/hbase-hadoop2-compat/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWALSourceImpl.java
@@ -40,6 +40,7 @@ public class MetricsWALSourceImpl extends BaseSourceImpl implements MetricsWALSo
   private final MutableFastCounter slowAppendCount;
   private final MutableFastCounter logRollRequested;
   private final MutableFastCounter lowReplicationLogRollRequested;
+  private final MutableFastCounter writtenBytes;
 
   public MetricsWALSourceImpl() {
     this(METRICS_NAME, METRICS_DESCRIPTION, METRICS_CONTEXT, METRICS_JMX_CONTEXT);
@@ -62,6 +63,7 @@ public class MetricsWALSourceImpl extends BaseSourceImpl implements MetricsWALSo
         this.getMetricsRegistry().newCounter(ROLL_REQUESTED, ROLL_REQUESTED_DESC, 0L);
     lowReplicationLogRollRequested = this.getMetricsRegistry()
         .newCounter(LOW_REPLICA_ROLL_REQUESTED, LOW_REPLICA_ROLL_REQUESTED_DESC, 0L);
+    writtenBytes = this.getMetricsRegistry().newCounter(WRITTEN_BYTES, WRITTEN_BYTES_DESC, 0l);
   }
 
   @Override
@@ -103,4 +105,15 @@ public class MetricsWALSourceImpl extends BaseSourceImpl implements MetricsWALSo
   public long getSlowAppendCount() {
     return slowAppendCount.value();
   }
+
+  @Override
+  public void incrementWrittenBytes(long val) {
+    writtenBytes.incr(val);
+  }
+
+  @Override
+  public long getWrittenBytes() {
+    return writtenBytes.value();
+  }
+
 }
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWAL.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWAL.java
index 24fd9405571..99792e558a4 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWAL.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/MetricsWAL.java
@@ -55,6 +55,7 @@ public class MetricsWAL extends WALActionsListener.Base {
     source.incrementAppendCount();
     source.incrementAppendTime(time);
     source.incrementAppendSize(size);
+    source.incrementWrittenBytes(size);
 
     if (time > 1000) {
       source.incrementSlowAppendCount();
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestMetricsWAL.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestMetricsWAL.java
index ba6915b636e..2e2aa080e73 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestMetricsWAL.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestMetricsWAL.java
@@ -66,4 +66,15 @@ public class TestMetricsWAL {
     metricsWAL.postAppend(1, 2000);
     assertEquals(2, source.getSlowAppendCount());
   }
+
+  @Test
+  public void testWalWrittenInBytes() throws Exception {
+    MetricsWALSource source = mock(MetricsWALSourceImpl.class);
+    MetricsWAL metricsWAL = new MetricsWAL(source);
+    metricsWAL.postAppend(100, 900);
+    metricsWAL.postAppend(200, 2000);
+    verify(source, times(1)).incrementWrittenBytes(100);
+    verify(source, times(1)).incrementWrittenBytes(200);
+  }
+
 }
\ No newline at end of file