diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
index f9cd6d077a4..2a1a8c85f40 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
@@ -355,6 +355,18 @@ public final class HConstants {
    */
   public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
 
+  /**
+   * Block updates if memstore has hbase.hregion.memstore.block.multiplier
+   * times hbase.hregion.memstore.flush.size bytes.  Useful preventing
+   * runaway memstore during spikes in update traffic.
+   */
+  public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
+          "hbase.hregion.memstore.block.multiplier";
+
+  /**
+   * Default value for hbase.hregion.memstore.block.multiplier
+   */
+  public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
 
   /** Conf key for the memstore size at which we flush the memstore */
   public static final String HREGION_MEMSTORE_FLUSH_SIZE =
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
index ebbb5823009..568a7c3ee16 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
@@ -758,7 +758,8 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
     }
     this.memstoreFlushSize = flushSize;
     this.blockingMemStoreSize = this.memstoreFlushSize *
-        conf.getLong("hbase.hregion.memstore.block.multiplier", 2);
+        conf.getLong(HConstants.HREGION_MEMSTORE_BLOCK_MULTIPLIER,
+                HConstants.DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER);
   }
 
   /**
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientPushback.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientPushback.java
index 294d7a9de16..995e3e505cc 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientPushback.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientPushback.java
@@ -73,7 +73,7 @@ public class TestClientPushback {
     // load
     conf.setLong(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, flushSizeBytes);
     // ensure we block the flushes when we are double that flushsize
-    conf.setLong("hbase.hregion.memstore.block.multiplier", 2);
+    conf.setLong(HConstants.HREGION_MEMSTORE_BLOCK_MULTIPLIER, HConstants.DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER);
 
     UTIL.startMiniCluster(1);
     UTIL.createTable(tableName, family);
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestCompaction.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestCompaction.java
index fcc9fc32a19..122b7a5a400 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestCompaction.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestCompaction.java
@@ -104,7 +104,7 @@ public class TestCompaction {
 
     // Set cache flush size to 1MB
     conf.setInt(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, 1024 * 1024);
-    conf.setInt("hbase.hregion.memstore.block.multiplier", 100);
+    conf.setInt(HConstants.HREGION_MEMSTORE_BLOCK_MULTIPLIER, 100);
     conf.set(CompactionThroughputControllerFactory.HBASE_THROUGHPUT_CONTROLLER_KEY,
       NoLimitCompactionThroughputController.class.getName());
     compactionThreshold = conf.getInt("hbase.hstore.compactionThreshold", 3);
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMajorCompaction.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMajorCompaction.java
index aaf20da8ce9..0409df3c3fa 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMajorCompaction.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMajorCompaction.java
@@ -92,7 +92,7 @@ public class TestMajorCompaction {
 
     // Set cache flush size to 1MB
     conf.setInt(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, 1024*1024);
-    conf.setInt("hbase.hregion.memstore.block.multiplier", 100);
+    conf.setInt(HConstants.HREGION_MEMSTORE_BLOCK_MULTIPLIER, 100);
     compactionThreshold = conf.getInt("hbase.hstore.compactionThreshold", 3);
 
     secondRowBytes = START_KEY_BYTES.clone();
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMinorCompaction.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMinorCompaction.java
index 2504d9c2f12..47f3a8facd5 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMinorCompaction.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMinorCompaction.java
@@ -69,7 +69,7 @@ public class TestMinorCompaction {
 
     // Set cache flush size to 1MB
     conf.setInt(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, 1024*1024);
-    conf.setInt("hbase.hregion.memstore.block.multiplier", 100);
+    conf.setInt(HConstants.HREGION_MEMSTORE_BLOCK_MULTIPLIER, 100);
     compactionThreshold = conf.getInt("hbase.hstore.compactionThreshold", 3);
 
     firstRowBytes = START_KEY_BYTES;