HBASE-29082: Support for custom meta table name suffix

hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java

@@ -1641,6 +1641,19 @@ public enum OperationStatusCode {
    */
   public final static boolean REJECT_DECOMMISSIONED_HOSTS_DEFAULT = false;
 
+  /**
+   * Adds a suffix to the meta table name: value=’test’ -> ‘hbase:meta_test’
+   * Added in HBASE-XXXXX to support having multiple hbase:meta tables (with distinct names )to
+   * enable storage sharing by more than one clusters.
+   */
+
+  public final static String HBASE_META_TABLE_SUFFIX = "hbase.meta.table.suffix";
+
+  /**
+   * Default value of {@link #HBASE_META_TABLE_SUFFIX}
+   */
+  public final static String HBASE_META_TABLE_SUFFIX_DEFAULT_VALUE = "";
+
   private HConstants() {
     // Can't be instantiated with this ctor.
   }

hbase-common/src/main/java/org/apache/hadoop/hbase/TableName.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.hbase;
 
 import java.nio.ByteBuffer;
+import org.apache.hadoop.conf.Configuration;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Set;
@@ -27,6 +28,8 @@
 import org.apache.yetus.audience.InterfaceAudience;
 
 import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Immutable POJO class for representing a table name. Which is of the form: <table
@@ -44,6 +47,8 @@
  */
 @InterfaceAudience.Public
 public final class TableName implements Comparable<TableName> {
+  private static final Logger LOG = LoggerFactory.getLogger(TableName.class);
+
 
   /** See {@link #createTableNameIfNecessary(ByteBuffer, ByteBuffer)} */
   private static final Set<TableName> tableCache = new CopyOnWriteArraySet<>();
@@ -65,9 +70,26 @@ public final class TableName implements Comparable<TableName> {
   public static final String VALID_USER_TABLE_REGEX = "(?:(?:(?:" + VALID_NAMESPACE_REGEX + "\\"
     + NAMESPACE_DELIM + ")?)" + "(?:" + VALID_TABLE_QUALIFIER_REGEX + "))";
 
-  /** The hbase:meta table's name. */
-  public static final TableName META_TABLE_NAME =
-    valueOf(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR, "meta");
+  /** The name of hbase meta table could either be hbase:meta_xxx or 'hbase:meta' otherwise.
+   * Config hbase.meta.table.suffix will govern the decision of adding suffix to the habase:meta */
+  public static final TableName META_TABLE_NAME;
+  static {
+    Configuration conf = HBaseConfiguration.create();
+    META_TABLE_NAME = initializeHbaseMetaTableName(conf);
+  }
+
+  static TableName initializeHbaseMetaTableName(Configuration conf) {
+    String suffix_val = String.valueOf(conf.getStrings(
+      HConstants.HBASE_META_TABLE_SUFFIX, HConstants.HBASE_META_TABLE_SUFFIX_DEFAULT_VALUE));
+
+    if (suffix_val == null||suffix_val.isEmpty()) {
+      LOG.debug("Default value for Hbase meta table is being chosen.");
+      return TableName.META_TABLE_NAME;
+    }
+    LOG.debug("Suffix value for Hbase meta table is being chosen.");
+    return valueOf(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR, "meta_"
+      + suffix_val);
+  }
 
   /**
    * The Namespace table's name.

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

@@ -1094,7 +1094,7 @@ private void finishActiveMasterInitialization() throws IOException, InterruptedE
         .filter(p -> p instanceof InitMetaProcedure).map(o -> (InitMetaProcedure) o).findAny();
       initMetaProc = optProc.orElseGet(() -> {
         // schedule an init meta procedure if meta has not been deployed yet
-        InitMetaProcedure temp = new InitMetaProcedure();
+        InitMetaProcedure temp = new InitMetaProcedure(conf);
         procedureExecutor.submitProcedure(temp);
         return temp;
       });

hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/InitMetaProcedure.java

@@ -19,6 +19,7 @@
 
 import static org.apache.hadoop.hbase.NamespaceDescriptor.DEFAULT_NAMESPACE;
 import static org.apache.hadoop.hbase.NamespaceDescriptor.SYSTEM_NAMESPACE;
+import static org.apache.hadoop.hbase.TableName.valueOf;
 import static org.apache.hadoop.hbase.master.TableNamespaceManager.insertNamespaceToMeta;
 import static org.apache.hadoop.hbase.master.procedure.AbstractStateMachineNamespaceProcedure.createDirectory;
 
@@ -28,6 +29,9 @@
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseIOException;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.NamespaceDescriptor;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.TableDescriptor;
@@ -61,9 +65,21 @@ public class InitMetaProcedure extends AbstractStateMachineTableProcedure<InitMe
 
   private RetryCounter retryCounter;
 
+  protected final Configuration conf;
+  public InitMetaProcedure(Configuration conf) {
+    this.conf = conf;
+  }
+
   @Override
   public TableName getTableName() {
-    return TableName.META_TABLE_NAME;
+    String suffix_val = String.valueOf(conf.getStrings(
+      HConstants.HBASE_META_TABLE_SUFFIX, HConstants.HBASE_META_TABLE_SUFFIX_DEFAULT_VALUE));
+
+    if (suffix_val == null||suffix_val.isEmpty()) {
+      return TableName.META_TABLE_NAME;
+    }
+    return valueOf(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR, "meta_"
+      + suffix_val);
   }
 
   @Override
@@ -78,6 +94,7 @@ private static TableDescriptor writeFsLayout(Path rootDir, Configuration conf)
     Path tableDir = CommonFSUtils.getTableDir(rootDir, TableName.META_TABLE_NAME);
     if (fs.exists(tableDir) && !fs.delete(tableDir, true)) {
       LOG.warn("Can not delete partial created meta table, continue...");
+      throw new HBaseIOException("Specified meta table already exists.");
     }
     // Bootstrapping, make sure blockcache is off. Else, one will be
     // created here in bootstrap and it'll need to be cleaned up. Better to