HBASE-30299 SimpleRegionNormalizer should not attempt to merge primary and secondary replicas (#8498)

Signed-off-by: Charles Connell <cconnell@apache.org>
Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org>

Author: SaadASTheDev

hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.java

@@ -649,6 +649,8 @@ public NormalizeContext(final TableDescriptor tableDescriptor) {
       regionStates =
         SimpleRegionNormalizer.this.masterServices.getAssignmentManager().getRegionStates();
       tableRegions = regionStates.getRegionsOfTable(tableName);
+
+      tableRegions.removeIf(r -> r.getReplicaId() != RegionInfo.DEFAULT_REPLICA_ID);
       // The list of regionInfo from getRegionsOfTable() is ordered by regionName.
       // regionName does not necessary guarantee the order by STARTKEY (let's say 'aa1', 'aa1!',
       // in order by regionName, it will be 'aa1!' followed by 'aa1').

hbase-server/src/test/java/org/apache/hadoop/hbase/master/normalizer/TestSimpleRegionNormalizer.java

@@ -750,4 +750,27 @@ private static Map<byte[], Integer> createRegionSizesMap(final List<RegionInfo>
     }
     return ret;
   }
+
+  @Test
+  public void testIgnoresSecondaryReplicasForMergeAndSplitPlanning() {
+    conf.setBoolean(SPLIT_ENABLED_KEY, true);
+    conf.setBoolean(MERGE_ENABLED_KEY, true);
+    conf.setInt(MERGE_MIN_REGION_COUNT_KEY, 1);
+    conf.setInt(MERGE_MIN_REGION_SIZE_MB_KEY, 0);
+
+    final List<RegionInfo> primaryRegions = createRegionInfos(tableName, 5);
+    final List<RegionInfo> allRegions = new ArrayList<>(primaryRegions);
+    for (RegionInfo primary : primaryRegions) {
+      allRegions.add(RegionInfoBuilder.newBuilder(tableName).setStartKey(primary.getStartKey())
+        .setEndKey(primary.getEndKey()).setRegionId(primary.getRegionId()).setReplicaId(1).build());
+    }
+
+    final Map<byte[], Integer> regionSizes = createRegionSizesMap(primaryRegions, 15, 5, 5, 15, 16);
+    setupMocksForNormalizer(regionSizes, allRegions);
+
+    final List<NormalizationPlan> plans = normalizer.computePlansForTable(tableDescriptor);
+    assertThat(plans, hasSize(1));
+    assertThat(plans, contains(new MergeNormalizationPlan.Builder()
+      .addTarget(primaryRegions.get(1), 5).addTarget(primaryRegions.get(2), 5).build()));
+  }
 }