Revert "HBASE-25293 Followup jira to address the client handling issue when chaning from meta replica to non-meta-replica at the server side."

This reverts commit c1aa3b24e9.

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncNonMetaRegionLocator.java

@@ -211,7 +211,7 @@ class AsyncNonMetaRegionLocator {
 
         this.metaReplicaSelector = CatalogReplicaLoadBalanceSelectorFactory.createSelector(
           replicaSelectorClass, META_TABLE_NAME, conn, () -> {
-            int numOfReplicas = CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS;
+            int numOfReplicas = 1;
             try {
               RegionLocations metaLocations = conn.registry.getMetaRegionLocations().get(
                 conn.connConf.getReadRpcTimeoutNs(), TimeUnit.NANOSECONDS);

hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSelector.java

@@ -28,8 +28,6 @@ import org.apache.yetus.audience.InterfaceAudience;
 @InterfaceAudience.Private
 interface CatalogReplicaLoadBalanceSelector {
 
-  int UNINITIALIZED_NUM_OF_REPLICAS = -1;
-
   /**
    * This method is called when input location is stale, i.e, when clients run into
    * org.apache.hadoop.hbase.NotServingRegionException.

hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSimpleSelector.java

@@ -108,6 +108,7 @@ class CatalogReplicaLoadBalanceSimpleSelector implements
   private final TableName tableName;
   private final IntSupplier getNumOfReplicas;
   private volatile boolean isStopped = false;
+  private final static int UNINITIALIZED_NUM_OF_REPLICAS = -1;
 
   CatalogReplicaLoadBalanceSimpleSelector(TableName tableName, AsyncConnectionImpl conn,
     IntSupplier getNumOfReplicas) {
@@ -116,7 +117,7 @@ class CatalogReplicaLoadBalanceSimpleSelector implements
     this.getNumOfReplicas = getNumOfReplicas;
 
     // This numOfReplicas is going to be lazy initialized.
-    this.numOfReplicas = CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS;
+    this.numOfReplicas = UNINITIALIZED_NUM_OF_REPLICAS;
     // Start chores
     this.conn.getChoreService().scheduleChore(getCacheCleanupChore(this));
     this.conn.getChoreService().scheduleChore(getRefreshReplicaCountChore(this));
@@ -145,7 +146,7 @@ class CatalogReplicaLoadBalanceSimpleSelector implements
    */
   private int getRandomReplicaId() {
     int cachedNumOfReplicas = this.numOfReplicas;
-    if (cachedNumOfReplicas == CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS) {
+    if (cachedNumOfReplicas == UNINITIALIZED_NUM_OF_REPLICAS) {
       cachedNumOfReplicas = refreshCatalogReplicaCount();
       this.numOfReplicas = cachedNumOfReplicas;
     }
@@ -261,16 +262,16 @@ class CatalogReplicaLoadBalanceSimpleSelector implements
   private int refreshCatalogReplicaCount() {
     int newNumOfReplicas = this.getNumOfReplicas.getAsInt();
     LOG.debug("Refreshed replica count {}", newNumOfReplicas);
-    // If the returned number of replicas is -1, it is caused by failure to fetch the
+    if (newNumOfReplicas == 1) {
-    // replica count. Do not update the numOfReplicas in this case.
+      LOG.warn("Table {}'s region replica count is 1, maybe a misconfiguration or failure to "
-    if (newNumOfReplicas == CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS) {
+        + "fetch the replica count", tableName);
-      LOG.error("Failed to fetch Table {}'s region replica count", tableName);
-      return this.numOfReplicas;
     }
-
     int cachedNumOfReplicas = this.numOfReplicas;
+
+    // If the returned number of replicas is 1, it is mostly caused by failure to fetch the
+    // replica count. Do not update the numOfReplicas in this case.
     if ((cachedNumOfReplicas == UNINITIALIZED_NUM_OF_REPLICAS) ||
-      (cachedNumOfReplicas != newNumOfReplicas)) {
+      ((cachedNumOfReplicas != newNumOfReplicas) && (newNumOfReplicas != 1))) {
       this.numOfReplicas = newNumOfReplicas;
     }
     return newNumOfReplicas;

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestCatalogReplicaLoadBalanceSimpleSelector.java

@@ -1,132 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.hadoop.hbase.client;
-
-import static org.apache.hadoop.hbase.HConstants.EMPTY_START_ROW;
-import static org.apache.hadoop.hbase.TableName.META_TABLE_NAME;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotEquals;
-import java.io.IOException;
-import java.util.concurrent.TimeUnit;
-import org.apache.commons.io.IOUtils;
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HBaseClassTestRule;
-import org.apache.hadoop.hbase.HBaseTestingUtility;
-import org.apache.hadoop.hbase.RegionLocations;
-import org.apache.hadoop.hbase.TableName;
-import org.apache.hadoop.hbase.security.User;
-import org.apache.hadoop.hbase.testclassification.ClientTests;
-import org.apache.hadoop.hbase.testclassification.MediumTests;
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
-import org.junit.ClassRule;
-import org.junit.Test;
-import org.junit.experimental.categories.Category;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-@Category({ MediumTests.class, ClientTests.class })
-public class TestCatalogReplicaLoadBalanceSimpleSelector {
-
-  @ClassRule
-  public static final HBaseClassTestRule CLASS_RULE =
-    HBaseClassTestRule.forClass(TestCatalogReplicaLoadBalanceSimpleSelector.class);
-
-  private static final Logger LOG = LoggerFactory.getLogger(
-    TestCatalogReplicaLoadBalanceSimpleSelector.class);
-
-  private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
-
-  private static final int NB_SERVERS = 4;
-  private static int numOfMetaReplica = NB_SERVERS - 1;
-
-  private static AsyncConnectionImpl CONN;
-
-  private static ConnectionRegistry registry;
-  private static Admin admin;
-
-  @BeforeClass
-  public static void setUp() throws Exception {
-    Configuration conf = TEST_UTIL.getConfiguration();
-
-    TEST_UTIL.startMiniCluster(NB_SERVERS);
-    admin = TEST_UTIL.getAdmin();
-    admin.balancerSwitch(false, true);
-
-    // Enable hbase:meta replication.
-    HBaseTestingUtility.setReplicas(admin, TableName.META_TABLE_NAME, numOfMetaReplica);
-    TEST_UTIL.waitFor(30000, () -> TEST_UTIL.getMiniHBaseCluster().getRegions(
-      TableName.META_TABLE_NAME).size() >= numOfMetaReplica);
-
-    registry = ConnectionRegistryFactory.getRegistry(TEST_UTIL.getConfiguration());
-    CONN = new AsyncConnectionImpl(conf, registry,
-      registry.getClusterId().get(), null, User.getCurrent());
-  }
-
-  @AfterClass
-  public static void tearDown() throws Exception {
-    IOUtils.closeQuietly(CONN);
-    TEST_UTIL.shutdownMiniCluster();
-  }
-
-  @Test
-  public void testMetaChangeFromReplicaNoReplica() throws IOException, InterruptedException {
-    String replicaSelectorClass = CONN.getConfiguration().
-      get(RegionLocator.LOCATOR_META_REPLICAS_MODE_LOADBALANCE_SELECTOR,
-        CatalogReplicaLoadBalanceSimpleSelector.class.getName());
-
-    CatalogReplicaLoadBalanceSelector metaSelector = CatalogReplicaLoadBalanceSelectorFactory
-      .createSelector(replicaSelectorClass, META_TABLE_NAME, CONN, () -> {
-        int numOfReplicas = CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS;
-        try {
-          RegionLocations metaLocations = CONN.registry.getMetaRegionLocations().get
-            (CONN.connConf.getReadRpcTimeoutNs(), TimeUnit.NANOSECONDS);
-          numOfReplicas = metaLocations.size();
-        } catch (Exception e) {
-          LOG.error("Failed to get table {}'s region replication, ", META_TABLE_NAME, e);
-        }
-        return numOfReplicas;
-      });
-
-    assertNotEquals(
-      metaSelector.select(TableName.valueOf("test"), EMPTY_START_ROW, RegionLocateType.CURRENT),
-      RegionReplicaUtil.DEFAULT_REPLICA_ID);
-
-    // Change to No meta replica
-    HBaseTestingUtility.setReplicas(admin, TableName.META_TABLE_NAME, 1);
-    TEST_UTIL.waitFor(30000, () -> TEST_UTIL.getMiniHBaseCluster().getRegions(
-      TableName.META_TABLE_NAME).size() == 1);
-
-    CatalogReplicaLoadBalanceSelector metaSelectorWithNoReplica =
-      CatalogReplicaLoadBalanceSelectorFactory.createSelector(
-        replicaSelectorClass, META_TABLE_NAME, CONN, () -> {
-        int numOfReplicas = CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS;
-        try {
-          RegionLocations metaLocations = CONN.registry.getMetaRegionLocations().get(
-            CONN.connConf.getReadRpcTimeoutNs(), TimeUnit.NANOSECONDS);
-          numOfReplicas = metaLocations.size();
-        } catch (Exception e) {
-          LOG.error("Failed to get table {}'s region replication, ", META_TABLE_NAME, e);
-        }
-        return numOfReplicas;
-      });
-    assertEquals(
-      metaSelectorWithNoReplica.select(TableName.valueOf("test"), EMPTY_START_ROW,
-        RegionLocateType.CURRENT), RegionReplicaUtil.DEFAULT_REPLICA_ID);
-  }
-}