From 00805b399f0b953efe510ff3ef8584c39171019b Mon Sep 17 00:00:00 2001
From: Josh Elser <elserj@apache.org>
Date: Mon, 7 Dec 2015 12:51:44 -0500
Subject: [PATCH] HBASE-14838 Add clarification docs to SimpleRegionNormalizer.

Signed-off-by: Sean Busbey <busbey@cloudera.com>
---
 .../hbase/master/normalizer/SimpleRegionNormalizer.java       | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java
index d843bd18c49..659b3dc02d1 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java
@@ -45,6 +45,10 @@ import java.util.List;
  *    to merge, if R1 + R1 &lt;  S, and normalization stops
  *  <li> Otherwise, no action is performed
  * </ol>
+ * <p>
+ * Region sizes are coarse and approximate on the order of megabytes. Additionally,
+ * "empty" regions (less than 1MB, with the previous note) are not merged away. This
+ * is by design to prevent normalization from undoing the pre-splitting of a table.
  */
 @InterfaceAudience.Private
 public class SimpleRegionNormalizer implements RegionNormalizer {