From 10176955cd3415929ee418f2d6ee59ef09e1b8bd Mon Sep 17 00:00:00 2001
From: haxiaolin <linkaline11@gmail.com>
Date: Tue, 24 Nov 2020 12:05:05 +0800
Subject: [PATCH] HBASE-25322 Redundant Reference file in bottom region of
 split

---
 .../hbase/regionserver/HRegionFileSystem.java |  3 +-
 .../master/assignment/TestRegionSplit.java    | 46 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionFileSystem.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionFileSystem.java
index d5ef30ecc79f..bb2328c6c0b5 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionFileSystem.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionFileSystem.java
@@ -682,9 +682,9 @@ public Path splitStoreFile(RegionInfo hri, String familyName, HStoreFile f, byte
       // If it is outside the range, return directly.
       f.initReader();
       try {
+        Cell splitKey = PrivateCellUtil.createFirstOnRow(splitRow);
         if (top) {
           //check if larger than last key.
-          Cell splitKey = PrivateCellUtil.createFirstOnRow(splitRow);
           Optional<Cell> lastKey = f.getLastKey();
           // If lastKey is null means storefile is empty.
           if (!lastKey.isPresent()) {
@@ -695,7 +695,6 @@ public Path splitStoreFile(RegionInfo hri, String familyName, HStoreFile f, byte
           }
         } else {
           //check if smaller than first key
-          Cell splitKey = PrivateCellUtil.createLastOnRow(splitRow);
           Optional<Cell> firstKey = f.getFirstKey();
           // If firstKey is null means storefile is empty.
           if (!firstKey.isPresent()) {
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestRegionSplit.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestRegionSplit.java
index 5fe45b7a387b..186edf9eae95 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestRegionSplit.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestRegionSplit.java
@@ -18,6 +18,7 @@
 package org.apache.hadoop.hbase.master.assignment;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import java.io.IOException;
 import org.apache.hadoop.conf.Configuration;
@@ -33,6 +34,7 @@
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureTestingUtility;
 import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
 import org.apache.hadoop.hbase.procedure2.ProcedureTestingUtility;
+import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -126,7 +128,8 @@ public void testSplitTableRegion() throws Exception {
     ProcedureTestingUtility.waitProcedure(procExec, procId);
     ProcedureTestingUtility.assertProcNotFailed(procExec, procId);
 
-    assertTrue("not able to split table", UTIL.getHBaseCluster().getRegions(tableName).size() == 2);
+    assertTrue("not able to split table",
+      UTIL.getHBaseCluster().getRegions(tableName).size() == 2);
 
     //disable table
     UTIL.getAdmin().disableTable(tableName);
@@ -150,6 +153,47 @@ public void testSplitTableRegion() throws Exception {
         UTIL.getHBaseCluster().getRegions(tableName).size());
   }
 
+  @Test
+  public void testSplitStoreFiles() throws Exception {
+    final TableName tableName = TableName.valueOf(name.getMethodName());
+    final ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
+
+    RegionInfo[] regions = MasterProcedureTestingUtility.createTable(procExec, tableName,
+      null, ColumnFamilyName);
+    // flush the memstore
+    insertData(tableName);
+
+    // assert the hfile count of the table
+    int storeFilesCountSum = 0;
+    for(HRegion region : UTIL.getHBaseCluster().getRegions(tableName)){
+      storeFilesCountSum += region.getStore(Bytes.toBytes(ColumnFamilyName)).getStorefiles().size();
+    }
+    assertEquals(1, storeFilesCountSum);
+
+    // split at the start row
+    byte[] splitKey = Bytes.toBytes("" + startRowNum);
+
+    assertNotNull("Not able to find a splittable region", regions);
+    assertEquals("Not able to find a splittable region", 1, regions.length);
+
+    // Split region of the table
+    long procId = procExec.submitProcedure(
+      new SplitTableRegionProcedure(procExec.getEnvironment(), regions[0], splitKey));
+    // Wait the completion
+    ProcedureTestingUtility.waitProcedure(procExec, procId);
+    ProcedureTestingUtility.assertProcNotFailed(procExec, procId);
+
+    assertEquals("Not able to split table",
+      2, UTIL.getHBaseCluster().getRegions(tableName).size());
+
+    // assert sum of the hfiles of all regions
+    int childStoreFilesSum = 0;
+    for(HRegion region : UTIL.getHBaseCluster().getRegions(tableName)){
+      childStoreFilesSum += region.getStore(Bytes.toBytes(ColumnFamilyName)).getStorefiles().size();
+    }
+    assertEquals(1, childStoreFilesSum);
+  }
+
   private void insertData(final TableName tableName) throws IOException {
     Table t = UTIL.getConnection().getTable(tableName);
     Put p;