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 c1aa3b2.

Author: Huaxiang Sun

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

@@ -211,7 +211,7 @@ private boolean tryComplete(LocateRequest req, CompletableFuture<RegionLocations
 
         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 @@
 @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 @@ public String toString() {
   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 @@ public String toString() {
     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 @@ public void onError(HRegionLocation loc) {
    */
   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 @@ private void cleanupReplicaReplicaStaleCache() {
   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
-    // replica count. Do not update the numOfReplicas in this case.
-    if (newNumOfReplicas == CatalogReplicaLoadBalanceSelector.UNINITIALIZED_NUM_OF_REPLICAS) {
-      LOG.error("Failed to fetch Table {}'s region replica count", tableName);
-      return this.numOfReplicas;
+    if (newNumOfReplicas == 1) {
+      LOG.warn("Table {}'s region replica count is 1, maybe a misconfiguration or failure to "
+        + "fetch the replica count", tableName);
     }
-
     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;