HBASE-23055 Alter hbase:meta (#667)

Make it so hbase:meta can be altered. TableState for hbase:meta
    is kept in Master. State is in-memory transient so if  Master
    fails, hbase:meta is ENABLED again. hbase:meta schema will be
    bootstrapped from the filesystem. Changes to filesystem schema
    are atomic so we should be ok if Master fails mid-edit (TBD)
    Undoes a bunch of guards that prevented our being able to edit
    hbase:meta. At minimmum, need to add in a bunch of WARNING.

    TODO: Tests, more clarity around hbase:meta table state, and undoing
    references to hard-coded hbase:meta regioninfo.

    M hbase-client/src/main/java/org/apache/hadoop/hbase/MetaTableAccessor.java
     Throw illegal access exception if you try to use MetaTableAccessor
     getting state of the hbase:meta table.

    M hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
     For table state, go to master rather than go to meta direct. Going
     to meta won't work for hbase;meta state. Puts load on Master.

    M hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
     Change isTableDisabled/Enabled implementation to ask the Master instead.
     This will give the Master's TableStateManager's opinion rather than
     client figuring it for themselves reading meta table direct.

    M hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
     TODO: Cleanup in here. Go to master for state, not to meta.

    M hbase-client/src/main/java/org/apache/hadoop/hbase/client/ZKAsyncRegistry.java
     Logging cleanup.

    M hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
     Shutdown access.

    M hbase-server/src/main/java/org/apache/hadoop/hbase/TableDescriptors.java
     Just cleanup.

    M hbase-server/src/main/java/org/apache/hadoop/hbase/master/TableStateManager.java
     Add state holder for hbase:meta.
     Removed unused methods.

    M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java
     Shut down access.

    M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/DisableTableProcedure.java
     Allow hbase:meta to be disabled.

    M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/EnableTableProcedure.java
     Allow hbase:meta to be enabled.

 Signed-off-by: Ramkrishna <ramkrishna.s.vasudevan@intel.com>

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -616,4 +616,5 @@ public class AsyncMetaTableAccessor {
     }
     return -1;
   }
+
 }

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

@@ -303,11 +303,18 @@ public class MetaTableAccessor {
    */
   public static HRegionLocation getRegionLocation(Connection connection, RegionInfo regionInfo)
       throws IOException {
-    byte[] row = getMetaKeyForRegion(regionInfo);
+    return getRegionLocation(getCatalogFamilyRow(connection, regionInfo),
-    Get get = new Get(row);
+        regionInfo, regionInfo.getReplicaId());
+  }
+
+  /**
+   * @return Return the {@link HConstants#CATALOG_FAMILY} row from hbase:meta.
+   */
+  public static Result getCatalogFamilyRow(Connection connection, RegionInfo ri)
+      throws IOException {
+    Get get = new Get(getMetaKeyForRegion(ri));
     get.addFamily(HConstants.CATALOG_FAMILY);
-    Result r = get(getMetaHTable(connection), get);
+    return get(getMetaHTable(connection), get);
-    return getRegionLocation(r, regionInfo, regionInfo.getReplicaId());
   }
 
   /** Returns the row key to use for this regionInfo */
@@ -1077,7 +1084,7 @@ public class MetaTableAccessor {
   public static TableState getTableState(Connection conn, TableName tableName)
       throws IOException {
     if (tableName.equals(TableName.META_TABLE_NAME)) {
-      return new TableState(tableName, TableState.State.ENABLED);
+      throw new IllegalAccessError("Go to the Master to find hbase:meta table state, not here");
     }
     Table metaHTable = getMetaHTable(conn);
     Get get = new Get(tableName.getName()).addColumn(getTableFamily(), getTableStateColumn());
@@ -1105,7 +1112,8 @@ public class MetaTableAccessor {
   }
 
   /**
-   * Updates state in META
+   * Updates state in META.
+   * Do not use. For internal use only.
    * @param conn connection to use
    * @param tableName table to look for
    */

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

@@ -90,6 +90,7 @@ import org.apache.hadoop.hbase.security.access.GetUserPermissionsRequest;
 import org.apache.hadoop.hbase.security.access.Permission;
 import org.apache.hadoop.hbase.security.access.ShadedAccessControlUtil;
 import org.apache.hadoop.hbase.security.access.UserPermission;
+
 import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;
 import org.apache.hadoop.hbase.snapshot.RestoreSnapshotException;
 import org.apache.hadoop.hbase.snapshot.SnapshotCreationException;
@@ -192,6 +193,8 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableDe
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableDescriptorsResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableNamesRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableNamesResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableStateRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableStateResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.IsBalancerEnabledRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.IsBalancerEnabledResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.IsCatalogJanitorEnabledRequest;
@@ -666,42 +669,25 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
 
   @Override
   public CompletableFuture<Boolean> isTableEnabled(TableName tableName) {
-    if (TableName.isMetaTableName(tableName)) {
+    return isTableState(tableName, TableState.State.ENABLED);
-      return CompletableFuture.completedFuture(true);
-    }
-    CompletableFuture<Boolean> future = new CompletableFuture<>();
-    addListener(AsyncMetaTableAccessor.getTableState(metaTable, tableName), (state, error) -> {
-      if (error != null) {
-        future.completeExceptionally(error);
-        return;
-      }
-      if (state.isPresent()) {
-        future.complete(state.get().inStates(TableState.State.ENABLED));
-      } else {
-        future.completeExceptionally(new TableNotFoundException(tableName));
-      }
-    });
-    return future;
   }
 
   @Override
   public CompletableFuture<Boolean> isTableDisabled(TableName tableName) {
-    if (TableName.isMetaTableName(tableName)) {
+    return isTableState(tableName, TableState.State.DISABLED);
-      return CompletableFuture.completedFuture(false);
+  }
-    }
+
-    CompletableFuture<Boolean> future = new CompletableFuture<>();
+  /**
-    addListener(AsyncMetaTableAccessor.getTableState(metaTable, tableName), (state, error) -> {
+   * @return Future that calls Master getTableState and compares to <code>state</code>
-      if (error != null) {
+   */
-        future.completeExceptionally(error);
+  private CompletableFuture<Boolean> isTableState(TableName tableName, TableState.State state) {
-        return;
+    return this.<Boolean> newMasterCaller().
-      }
+        action((controller, stub) ->
-      if (state.isPresent()) {
+      this.<GetTableStateRequest, GetTableStateResponse, Boolean> call(controller, stub,
-        future.complete(state.get().inStates(TableState.State.DISABLED));
+          GetTableStateRequest.newBuilder().
-      } else {
+              setTableName(ProtobufUtil.toProtoTableName(tableName)).build(),
-        future.completeExceptionally(new TableNotFoundException(tableName));
+        (s, c, req, done) -> s.getTableState(c, req, done),
-      }
+        resp -> resp.getTableState().getState().toString().equals(state.toString()))).call();
-    });
-    return future;
   }
 
   @Override

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -158,7 +158,8 @@ class ZKAsyncRegistry implements AsyncRegistry {
           }
           Pair<RegionState.State, ServerName> stateAndServerName = getStateAndServerName(proto);
           if (stateAndServerName.getFirst() != RegionState.State.OPEN) {
-            LOG.warn("Meta region is in state " + stateAndServerName.getFirst());
+            LOG.warn("hbase:meta region (replicaId={}) is in state {}", replicaId,
+                stateAndServerName.getFirst());
           }
           locs[DEFAULT_REPLICA_ID] = new HRegionLocation(
             getRegionInfoForDefaultReplica(FIRST_META_REGIONINFO), stateAndServerName.getSecond());
@@ -173,7 +174,7 @@ class ZKAsyncRegistry implements AsyncRegistry {
             LOG.warn("Failed to fetch " + path, error);
             locs[replicaId] = null;
           } else if (proto == null) {
-            LOG.warn("Meta znode for replica " + replicaId + " is null");
+            LOG.warn("hbase:meta znode for replica " + replicaId + " is null");
             locs[replicaId] = null;
           } else {
             Pair<RegionState.State, ServerName> stateAndServerName = getStateAndServerName(proto);
@@ -197,9 +198,8 @@ class ZKAsyncRegistry implements AsyncRegistry {
   public CompletableFuture<RegionLocations> getMetaRegionLocation() {
     CompletableFuture<RegionLocations> future = new CompletableFuture<>();
     addListener(
-      zk.list(znodePaths.baseZNode)
+      zk.list(znodePaths.baseZNode).thenApply(children -> children.stream().
-        .thenApply(children -> children.stream()
+          filter(c -> znodePaths.isMetaZNodePrefix(c)).collect(Collectors.toList())),
-          .filter(c -> c.startsWith(znodePaths.metaZNodePrefix)).collect(Collectors.toList())),
       (metaReplicaZNodes, error) -> {
         if (error != null) {
           future.completeExceptionally(error);

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -24,6 +24,7 @@ import static org.apache.hadoop.hbase.HConstants.SPLIT_LOGDIR_NAME;
 import static org.apache.hadoop.hbase.HConstants.ZOOKEEPER_ZNODE_PARENT;
 import static org.apache.hadoop.hbase.client.RegionInfo.DEFAULT_REPLICA_ID;
 
+import java.util.Collection;
 import java.util.Optional;
 import java.util.stream.IntStream;
 import org.apache.hadoop.conf.Configuration;
@@ -40,15 +41,24 @@ public class ZNodePaths {
   // TODO: Replace this with ZooKeeper constant when ZOOKEEPER-277 is resolved.
   public static final char ZNODE_PATH_SEPARATOR = '/';
 
-  public final static String META_ZNODE_PREFIX = "meta-region-server";
+  private static final String META_ZNODE_PREFIX = "meta-region-server";
   private static final String DEFAULT_SNAPSHOT_CLEANUP_ZNODE = "snapshot-cleanup";
 
   // base znode for this cluster
   public final String baseZNode;
-  // the prefix of meta znode, does not include baseZNode.
+
-  public final String metaZNodePrefix;
+  /**
-  // znodes containing the locations of the servers hosting the meta replicas
+   * The prefix of meta znode. Does not include baseZNode.
-  public final ImmutableMap<Integer, String> metaReplicaZNodes;
+   * Its a 'prefix' because meta replica id integer can be tagged on the end (if
+   * no number present, it is 'default' replica).
+   */
+  private final String metaZNodePrefix;
+
+  /**
+   * znodes containing the locations of the servers hosting the meta replicas
+   */
+  private final ImmutableMap<Integer, String> metaReplicaZNodes;
+
   // znode containing ephemeral nodes of the regionservers
   public final String rsZNode;
   // znode containing ephemeral nodes of the draining regionservers
@@ -158,21 +168,21 @@ public class ZNodePaths {
   }
 
   /**
-   * Is the znode of any meta replica
+   * @return true if the znode is a meta region replica
-   * @param node
-   * @return true or false
    */
   public boolean isAnyMetaReplicaZNode(String node) {
-    if (metaReplicaZNodes.containsValue(node)) {
+    return this.metaReplicaZNodes.containsValue(node);
-      return true;
-    }
-    return false;
   }
 
   /**
-   * Get the znode string corresponding to a replicaId
+   * @return Meta Replica ZNodes
-   * @param replicaId
+   */
-   * @return znode
+  public Collection<String> getMetaReplicaZNodes() {
+    return this.metaReplicaZNodes.values();
+  }
+
+  /**
+   * @return the znode string corresponding to a replicaId
    */
   public String getZNodeForReplica(int replicaId) {
     // return a newly created path but don't update the cache of paths
@@ -183,24 +193,21 @@ public class ZNodePaths {
   }
 
   /**
-   * Parse the meta replicaId from the passed znode
+   * Parse the meta replicaId from the passed znode name.
    * @param znode the name of the znode, does not include baseZNode
    * @return replicaId
    */
   public int getMetaReplicaIdFromZnode(String znode) {
-    if (znode.equals(metaZNodePrefix)) {
+    return znode.equals(metaZNodePrefix)?
-      return RegionInfo.DEFAULT_REPLICA_ID;
+        RegionInfo.DEFAULT_REPLICA_ID:
-    }
+        Integer.parseInt(znode.substring(metaZNodePrefix.length() + 1));
-    return Integer.parseInt(znode.substring(metaZNodePrefix.length() + 1));
   }
 
   /**
-   * Is it the default meta replica's znode
+   * @return True if meta znode.
-   * @param znode the name of the znode, does not include baseZNode
-   * @return true or false
    */
-  public boolean isDefaultMetaReplicaZnode(String znode) {
+  public boolean isMetaZNodePrefix(String znode) {
-    return metaReplicaZNodes.get(DEFAULT_REPLICA_ID).equals(znode);
+    return znode != null && znode.startsWith(this.metaZNodePrefix);
   }
 
   /**

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

@@ -1175,8 +1175,7 @@ public final class HConstants {
   /** Directories that are not HBase user table directories */
   public static final List<String> HBASE_NON_USER_TABLE_DIRS =
     Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
-      new String[] { TableName.META_TABLE_NAME.getNameAsString() },
+       HBASE_NON_TABLE_DIRS.toArray())));
-      HBASE_NON_TABLE_DIRS.toArray())));
 
   /** Health script related settings. */
   public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";

hbase-server/src/main/java/org/apache/hadoop/hbase/TableDescriptors.java

@@ -25,25 +25,19 @@ import org.apache.hadoop.hbase.client.TableDescriptor;
 
 /**
  * Get, remove and modify table descriptors.
- * Used by servers to host descriptors.
  */
 @InterfaceAudience.Private
 public interface TableDescriptors {
   /**
-   * @param tableName
    * @return TableDescriptor for tablename
-   * @throws IOException
    */
-  TableDescriptor get(final TableName tableName)
+  TableDescriptor get(final TableName tableName) throws IOException;
-      throws IOException;
 
   /**
    * Get Map of all NamespaceDescriptors for a given namespace.
    * @return Map of all descriptors.
-   * @throws IOException
    */
-  Map<String, TableDescriptor> getByNamespace(String name)
+  Map<String, TableDescriptor> getByNamespace(String name) throws IOException;
-  throws IOException;
 
   /**
    * Get Map of all TableDescriptors. Populates the descriptor cache as a
@@ -51,25 +45,19 @@ public interface TableDescriptors {
    * Notice: the key of map is the table name which contains namespace. It was generated by
    * {@link TableName#getNameWithNamespaceInclAsString()}.
    * @return Map of all descriptors.
-   * @throws IOException
    */
   Map<String, TableDescriptor> getAll() throws IOException;
 
   /**
    * Add or update descriptor
    * @param htd Descriptor to set into TableDescriptors
-   * @throws IOException
    */
-  void add(final TableDescriptor htd)
+  void add(final TableDescriptor htd) throws IOException;
-  throws IOException;
 
   /**
-   * @param tablename
    * @return Instance of table descriptor or null if none found.
-   * @throws IOException
    */
-  TableDescriptor remove(final TableName tablename)
+  TableDescriptor remove(final TableName tablename) throws IOException;
-  throws IOException;
 
   /**
    * Enables the tabledescriptor cache

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

@@ -49,7 +49,6 @@ import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.function.Function;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import javax.servlet.ServletException;
@@ -670,10 +669,6 @@ public class HMaster extends HRegionServer implements MasterServices {
     return connector.getLocalPort();
   }
 
-  @Override
-  protected Function<TableDescriptorBuilder, TableDescriptorBuilder> getMetaTableObserver() {
-    return builder -> builder.setRegionReplication(conf.getInt(HConstants.META_REPLICAS_NUM, HConstants.DEFAULT_META_REPLICA_NUM));
-  }
   /**
    * For compatibility, if failed with regionserver credentials, try the master one
    */
@@ -1035,7 +1030,7 @@ public class HMaster extends HRegionServer implements MasterServices {
     RegionState rs = this.assignmentManager.getRegionStates().
         getRegionState(RegionInfoBuilder.FIRST_META_REGIONINFO);
     LOG.info("hbase:meta {}", rs);
-    if (rs.isOffline()) {
+    if (rs != null && rs.isOffline()) {
       Optional<InitMetaProcedure> optProc = procedureExecutor.getProcedures().stream()
         .filter(p -> p instanceof InitMetaProcedure).map(o -> (InitMetaProcedure) o).findAny();
       initMetaProc = optProc.orElseGet(() -> {

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -34,7 +34,6 @@ import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.TableState;
-import org.apache.hadoop.hbase.exceptions.IllegalArgumentIOException;
 import org.apache.hadoop.hbase.util.IdReadWriteLock;
 import org.apache.hadoop.hbase.util.ZKDataMigrator;
 import org.apache.hadoop.hbase.zookeeper.ZKUtil;
@@ -53,8 +52,20 @@ import org.apache.hbase.thirdparty.com.google.common.collect.Sets;
 // TODO: Make this a guava Service
 @InterfaceAudience.Private
 public class TableStateManager {
-
   private static final Logger LOG = LoggerFactory.getLogger(TableStateManager.class);
+
+  /**
+   * All table state is kept in hbase:meta except that of hbase:meta itself.
+   * hbase:meta state is kept here locally in this in-memory variable. State
+   * for hbase:meta is not persistent. If this process dies, the hbase:meta
+   * state reverts to enabled. State is used so we can edit hbase:meta as we
+   * would any other table by disabling, altering, and then re-enabling. If this
+   * process dies in the midst of an edit, the table reverts to enabled. Schema
+   * is read from the filesystem. It is changed atomically so if we die midway
+   * through an edit we should be good.
+   */
+  private TableState.State metaTableState = TableState.State.ENABLED;
+
   /**
    * Set this key to false in Configuration to disable migrating table state from zookeeper so
    * hbase:meta table.
@@ -68,7 +79,7 @@ public class TableStateManager {
   private final ConcurrentMap<TableName, TableState.State> tableName2State =
     new ConcurrentHashMap<>();
 
-  public TableStateManager(MasterServices master) {
+  TableStateManager(MasterServices master) {
     this.master = master;
   }
 
@@ -87,61 +98,6 @@ public class TableStateManager {
     }
   }
 
-  /**
-   * Set table state to provided but only if table in specified states Caller should lock table on
-   * write.
-   * @param tableName table to change state for
-   * @param newState new state
-   * @param states states to check against
-   * @return null if succeed or table state if failed
-   */
-  public TableState setTableStateIfInStates(TableName tableName, TableState.State newState,
-      TableState.State... states) throws IOException {
-    ReadWriteLock lock = tnLock.getLock(tableName);
-    lock.writeLock().lock();
-    try {
-      TableState currentState = readMetaState(tableName);
-      if (currentState == null) {
-        throw new TableNotFoundException(tableName);
-      }
-      if (currentState.inStates(states)) {
-        updateMetaState(tableName, newState);
-        return null;
-      } else {
-        return currentState;
-      }
-    } finally {
-      lock.writeLock().unlock();
-    }
-  }
-
-  /**
-   * Set table state to provided but only if table not in specified states Caller should lock table
-   * on write.
-   * @param tableName table to change state for
-   * @param newState new state
-   * @param states states to check against
-   */
-  public boolean setTableStateIfNotInStates(TableName tableName, TableState.State newState,
-      TableState.State... states) throws IOException {
-    ReadWriteLock lock = tnLock.getLock(tableName);
-    lock.writeLock().lock();
-    try {
-      TableState currentState = readMetaState(tableName);
-      if (currentState == null) {
-        throw new TableNotFoundException(tableName);
-      }
-      if (!currentState.inStates(states)) {
-        updateMetaState(tableName, newState);
-        return true;
-      } else {
-        return false;
-      }
-    } finally {
-      lock.writeLock().unlock();
-    }
-  }
-
   public boolean isTableState(TableName tableName, TableState.State... states) {
     try {
       TableState tableState = getTableState(tableName);
@@ -155,6 +111,7 @@ public class TableStateManager {
 
   public void setDeletedTable(TableName tableName) throws IOException {
     if (tableName.equals(TableName.META_TABLE_NAME)) {
+      // Can't delete the hbase:meta table.
       return;
     }
     ReadWriteLock lock = tnLock.getLock(tableName);
@@ -183,7 +140,7 @@ public class TableStateManager {
    * @param states filter by states
    * @return tables in given states
    */
-  public Set<TableName> getTablesInStates(TableState.State... states) throws IOException {
+  Set<TableName> getTablesInStates(TableState.State... states) throws IOException {
     // Only be called in region normalizer, will not use cache.
     final Set<TableName> rv = Sets.newHashSet();
     MetaTableAccessor.fullScanTables(master.getConnection(), new MetaTableAccessor.Visitor() {
@@ -199,12 +156,6 @@ public class TableStateManager {
     return rv;
   }
 
-  public static class TableStateNotFoundException extends TableNotFoundException {
-    TableStateNotFoundException(TableName tableName) {
-      super(tableName.getNameAsString());
-    }
-  }
-
   @NonNull
   public TableState getTableState(TableName tableName) throws IOException {
     ReadWriteLock lock = tnLock.getLock(tableName);
@@ -212,7 +163,7 @@ public class TableStateManager {
     try {
       TableState currentState = readMetaState(tableName);
       if (currentState == null) {
-        throw new TableStateNotFoundException(tableName);
+        throw new TableNotFoundException("No state found for " + tableName);
       }
       return currentState;
     } finally {
@@ -221,22 +172,18 @@ public class TableStateManager {
   }
 
   private void updateMetaState(TableName tableName, TableState.State newState) throws IOException {
-    if (tableName.equals(TableName.META_TABLE_NAME)) {
-      if (TableState.State.DISABLING.equals(newState) ||
-        TableState.State.DISABLED.equals(newState)) {
-        throw new IllegalArgumentIOException("Cannot disable the meta table; " + newState);
-      }
-      // Otherwise, just return; no need to set ENABLED on meta -- it is always ENABLED.
-      return;
-    }
     boolean succ = false;
     try {
-      MetaTableAccessor.updateTableState(master.getConnection(), tableName, newState);
+      if (tableName.equals(TableName.META_TABLE_NAME)) {
-      tableName2State.put(tableName, newState);
+        this.metaTableState = newState;
+      } else {
+        MetaTableAccessor.updateTableState(master.getConnection(), tableName, newState);
+      }
+      this.tableName2State.put(tableName, newState);
       succ = true;
     } finally {
       if (!succ) {
-        tableName2State.remove(tableName);
+        this.tableName2State.remove(tableName);
       }
     }
     metaStateUpdated(tableName, newState);
@@ -255,7 +202,9 @@ public class TableStateManager {
     if (state != null) {
       return new TableState(tableName, state);
     }
-    TableState tableState = MetaTableAccessor.getTableState(master.getConnection(), tableName);
+    TableState tableState = tableName.equals(TableName.META_TABLE_NAME)?
+        new TableState(TableName.META_TABLE_NAME, this.metaTableState):
+        MetaTableAccessor.getTableState(master.getConnection(), tableName);
     if (tableState != null) {
       tableName2State.putIfAbsent(tableName, tableState.getState());
     }
@@ -263,10 +212,8 @@ public class TableStateManager {
   }
 
   public void start() throws IOException {
-    TableDescriptors tableDescriptors = master.getTableDescriptors();
     migrateZooKeeper();
-    Connection connection = master.getConnection();
+    fixTableStates(master.getTableDescriptors(), master.getConnection());
-    fixTableStates(tableDescriptors, connection);
   }
 
   private void fixTableStates(TableDescriptors tableDescriptors, Connection connection)
@@ -335,7 +282,7 @@ public class TableStateManager {
         TableState ts = null;
         try {
           ts = getTableState(entry.getKey());
-        } catch (TableStateNotFoundException e) {
+        } catch (TableNotFoundException e) {
           // This can happen; table exists but no TableState.
         }
         if (ts == null) {
@@ -377,4 +324,4 @@ public class TableStateManager {
       LOG.warn("Failed deleting table state from zookeeper", e);
     }
   }
-}
+}

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

@@ -147,8 +147,7 @@ public class RegionStateStore {
     }
   }
 
-  public void updateRegionLocation(RegionStateNode regionStateNode)
+  void updateRegionLocation(RegionStateNode regionStateNode) throws IOException {
-      throws IOException {
     if (regionStateNode.getRegionInfo().isMetaRegion()) {
       updateMetaLocation(regionStateNode.getRegionInfo(), regionStateNode.getRegionLocation(),
         regionStateNode.getState());

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

@@ -78,9 +78,7 @@ public class CreateTableProcedure
   @Override
   protected Flow executeFromState(final MasterProcedureEnv env, final CreateTableState state)
       throws InterruptedException {
-    if (LOG.isTraceEnabled()) {
+    LOG.info("{} execute state={}", this, state);
-      LOG.trace(this + " execute state=" + state);
-    }
     try {
       switch (state) {
         case CREATE_TABLE_PRE_OPERATION:

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

@@ -28,7 +28,6 @@ import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.client.BufferedMutator;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.TableState;
-import org.apache.hadoop.hbase.constraint.ConstraintException;
 import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
 import org.apache.hadoop.hbase.master.MasterFileSystem;
 import org.apache.hadoop.hbase.master.TableStateManager;
@@ -109,8 +108,8 @@ public class DisableTableProcedure
           setNextState(DisableTableState.DISABLE_TABLE_ADD_REPLICATION_BARRIER);
           break;
         case DISABLE_TABLE_ADD_REPLICATION_BARRIER:
-          if (env.getMasterServices().getTableDescriptors().get(tableName)
+          if (env.getMasterServices().getTableDescriptors().get(tableName).
-            .hasGlobalReplicationScope()) {
+              hasGlobalReplicationScope()) {
             MasterFileSystem fs = env.getMasterFileSystem();
             try (BufferedMutator mutator = env.getMasterServices().getConnection()
               .getBufferedMutator(TableName.META_TABLE_NAME)) {
@@ -242,10 +241,7 @@ public class DisableTableProcedure
    */
   private boolean prepareDisable(final MasterProcedureEnv env) throws IOException {
     boolean canTableBeDisabled = true;
-    if (tableName.equals(TableName.META_TABLE_NAME)) {
+    if (!MetaTableAccessor.tableExists(env.getMasterServices().getConnection(), tableName)) {
-      setFailure("master-disable-table", new ConstraintException("Cannot disable catalog table"));
-      canTableBeDisabled = false;
-    } else if (!MetaTableAccessor.tableExists(env.getMasterServices().getConnection(), tableName)) {
       setFailure("master-disable-table", new TableNotFoundException(tableName));
       canTableBeDisabled = false;
     } else if (!skipTableStateCheck) {

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,18 +20,19 @@ package org.apache.hadoop.hbase.master.procedure;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
-import org.apache.hadoop.hbase.Cell;
+import java.util.concurrent.ExecutionException;
+
 import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.MetaTableAccessor;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.TableNotDisabledException;
 import org.apache.hadoop.hbase.TableNotFoundException;
-import org.apache.hadoop.hbase.client.Connection;
+import org.apache.hadoop.hbase.client.AsyncClusterConnection;
-import org.apache.hadoop.hbase.client.Get;
+import org.apache.hadoop.hbase.client.AsyncConnection;
+import org.apache.hadoop.hbase.client.AsyncTable;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.RegionReplicaUtil;
-import org.apache.hadoop.hbase.client.Result;
-import org.apache.hadoop.hbase.client.Table;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.TableState;
 import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
@@ -45,6 +46,7 @@ import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.EnableTableState;
 
+
 @InterfaceAudience.Private
 public class EnableTableProcedure
     extends AbstractStateMachineTableProcedure<EnableTableState> {
@@ -57,7 +59,8 @@ public class EnableTableProcedure
 
   /**
    * Constructor
-   * @param env MasterProcedureEnv
+   *
+   * @param env       MasterProcedureEnv
    * @param tableName the table to operate on
    */
   public EnableTableProcedure(MasterProcedureEnv env, TableName tableName) {
@@ -66,11 +69,12 @@ public class EnableTableProcedure
 
   /**
    * Constructor
-   * @param env MasterProcedureEnv
+   *
+   * @param env       MasterProcedureEnv
    * @param tableName the table to operate on
    */
   public EnableTableProcedure(MasterProcedureEnv env, TableName tableName,
-      ProcedurePrepareLatch syncLatch) {
+                              ProcedurePrepareLatch syncLatch) {
     super(env, syncLatch);
     this.tableName = tableName;
   }
@@ -99,66 +103,53 @@ public class EnableTableProcedure
           setNextState(EnableTableState.ENABLE_TABLE_MARK_REGIONS_ONLINE);
           break;
         case ENABLE_TABLE_MARK_REGIONS_ONLINE:
-          Connection connection = env.getMasterServices().getConnection();
+          // Get the region replica count. If changed since disable, need to do
-          // we will need to get the tableDescriptor here to see if there is a change in the replica
+          // more work assigning.
-          // count
+          AsyncClusterConnection connection = env.getMasterServices().getAsyncClusterConnection();
-          TableDescriptor hTableDescriptor =
+          TableDescriptor tableDescriptor =
               env.getMasterServices().getTableDescriptors().get(tableName);
-
+          int configuredReplicaCount = tableDescriptor.getRegionReplication();
-          // Get the replica count
+          // Get regions for the table from memory; get both online and offline regions ('true').
-          int regionReplicaCount = hTableDescriptor.getRegionReplication();
-
-          // Get the regions for the table from memory; get both online and offline regions
-          // ('true').
           List<RegionInfo> regionsOfTable =
               env.getAssignmentManager().getRegionStates().getRegionsOfTable(tableName, true);
 
-          int currentMaxReplica = 0;
+          // How many replicas do we currently have? Check regions returned from
-          // Check if the regions in memory have replica regions as marked in META table
+          // in-memory state.
-          for (RegionInfo regionInfo : regionsOfTable) {
+          int currentMaxReplica = getMaxReplicaId(regionsOfTable);
-            if (regionInfo.getReplicaId() > currentMaxReplica) {
-              // Iterating through all the list to identify the highest replicaID region.
-              // We can stop after checking with the first set of regions??
-              currentMaxReplica = regionInfo.getReplicaId();
-            }
-          }
 
-          // read the META table to know the actual number of replicas for the table - if there
+          // Read the META table to know the number of replicas the table currently has.
-          // was a table modification on region replica then this will reflect the new entries also
+          // If there was a table modification on region replica count then need to
-          int replicasFound =
+          // adjust replica counts here.
-              getNumberOfReplicasFromMeta(connection, regionReplicaCount, regionsOfTable);
+          int replicasFound = getReplicaCount(connection, this.tableName);
-          assert regionReplicaCount - 1 == replicasFound;
+          LOG.info("replicasFound={} (configuredReplicaCount={} for {}", replicasFound,
-          LOG.info(replicasFound + " META entries added for the given regionReplicaCount "
+              configuredReplicaCount, tableName.getNameAsString());
-              + regionReplicaCount + " for the table " + tableName.getNameAsString());
+          if (currentMaxReplica == (configuredReplicaCount - 1)) {
-          if (currentMaxReplica == (regionReplicaCount - 1)) {
             if (LOG.isDebugEnabled()) {
-              LOG.debug("There is no change to the number of region replicas."
+              LOG.debug("No change in number of region replicas (configuredReplicaCount={});"
-                  + " Assigning the available regions." + " Current and previous"
+                  + " assigning.", configuredReplicaCount);
-                  + "replica count is " + regionReplicaCount);
             }
-          } else if (currentMaxReplica > (regionReplicaCount - 1)) {
+          } else if (currentMaxReplica > (configuredReplicaCount - 1)) {
-            // we have additional regions as the replica count has been decreased. Delete
+            // We have additional regions as the replica count has been decreased. Delete
             // those regions because already the table is in the unassigned state
             LOG.info("The number of replicas " + (currentMaxReplica + 1)
-                + "  is more than the region replica count " + regionReplicaCount);
+                + "  is more than the region replica count " + configuredReplicaCount);
-            List<RegionInfo> copyOfRegions = new ArrayList<RegionInfo>(regionsOfTable);
+            List<RegionInfo> copyOfRegions = new ArrayList<>(regionsOfTable);
             for (RegionInfo regionInfo : copyOfRegions) {
-              if (regionInfo.getReplicaId() > (regionReplicaCount - 1)) {
+              if (regionInfo.getReplicaId() > (configuredReplicaCount - 1)) {
                 // delete the region from the regionStates
                 env.getAssignmentManager().getRegionStates().deleteRegion(regionInfo);
                 // remove it from the list of regions of the table
-                LOG.info("The regioninfo being removed is " + regionInfo + " "
+                LOG.info("Removed replica={} of {}", regionInfo.getRegionId(), regionInfo);
-                    + regionInfo.getReplicaId());
                 regionsOfTable.remove(regionInfo);
               }
             }
           } else {
             // the replicasFound is less than the regionReplication
-            LOG.info("The number of replicas has been changed(increased)."
+            LOG.info("Number of replicas has increased. Assigning new region replicas." +
-                + " Lets assign the new region replicas. The previous replica count was "
+                    "The previous replica count was {}. The current replica count is {}.",
-                + (currentMaxReplica + 1) + ". The current replica count is " + regionReplicaCount);
+                (currentMaxReplica + 1), configuredReplicaCount);
-            regionsOfTable = RegionReplicaUtil.addReplicas(hTableDescriptor, regionsOfTable,
+            regionsOfTable = RegionReplicaUtil.addReplicas(tableDescriptor, regionsOfTable,
-              currentMaxReplica + 1, regionReplicaCount);
+                currentMaxReplica + 1, configuredReplicaCount);
           }
           // Assign all the table regions. (including region replicas if added).
           // createAssignProcedure will try to retain old assignments if possible.
@@ -175,40 +166,32 @@ public class EnableTableProcedure
         default:
           throw new UnsupportedOperationException("unhandled state=" + state);
       }
-    } catch (IOException e) {
+    } catch (IOException | ExecutionException e) {
       if (isRollbackSupported(state)) {
-        setFailure("master-enable-table", e);
+        setFailure("master-enable-table", getCause(e));
       } else {
-        LOG.warn(
+        LOG.warn("Retryable error enabling {}, state={}", tableName, state, getCause(e));
-          "Retriable error trying to enable table=" + tableName + " (in state=" + state + ")", e);
       }
     }
     return Flow.HAS_MORE_STATE;
   }
 
-  private int getNumberOfReplicasFromMeta(Connection connection, int regionReplicaCount,
+  /**
-      List<RegionInfo> regionsOfTable) throws IOException {
+   * @return If ExecutionException, pull out the cause.
-    Result r = getRegionFromMeta(connection, regionsOfTable);
+   */
-    int replicasFound = 0;
+  private Throwable getCause(Exception e) {
-    for (int i = 1; i < regionReplicaCount; i++) {
+    return e instanceof ExecutionException? ((ExecutionException)e).getCause(): e;
-      // Since we have already added the entries to the META we will be getting only that here
-      List<Cell> columnCells =
-          r.getColumnCells(HConstants.CATALOG_FAMILY, MetaTableAccessor.getServerColumn(i));
-      if (!columnCells.isEmpty()) {
-        replicasFound++;
-      }
-    }
-    return replicasFound;
   }
 
-  private Result getRegionFromMeta(Connection connection, List<RegionInfo> regionsOfTable)
+  /**
-      throws IOException {
+   * @return If hbase;meta table, it goes to the registry implementation which is what we want.
-    byte[] metaKeyForRegion = MetaTableAccessor.getMetaKeyForRegion(regionsOfTable.get(0));
+   */
-    Get get = new Get(metaKeyForRegion);
+  private int getReplicaCount(AsyncConnection connection, TableName tableName)
-    get.addFamily(HConstants.CATALOG_FAMILY);
+      throws ExecutionException, InterruptedException {
-    Table metaTable = MetaTableAccessor.getMetaHTable(connection);
+    AsyncTable t = connection.getTable(TableName.META_TABLE_NAME);
-    Result r = metaTable.get(get);
+    List<HRegionLocation> rls =
-    return r;
+        t.getRegionLocator().getRegionLocations(HConstants.EMPTY_START_ROW, true).get();
+    return rls.size();
   }
 
   @Override
@@ -408,4 +391,19 @@ public class EnableTableProcedure
       }
     }
   }
+
+  /**
+   * @return Maximum region replica id found in passed list of regions.
+   */
+  private static int getMaxReplicaId(List<RegionInfo> regions) {
+    int max = 0;
+    for (RegionInfo regionInfo: regions) {
+      if (regionInfo.getReplicaId() > max) {
+        // Iterating through all the list to identify the highest replicaID region.
+        // We can stop after checking with the first set of regions??
+        max = regionInfo.getReplicaId();
+      }
+    }
+    return max;
+  }
 }

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -23,10 +23,10 @@ import java.util.HashMap;
 import java.util.Map;
 import org.apache.hadoop.hbase.MetaTableAccessor;
 import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.master.TableStateManager;
-import org.apache.hadoop.hbase.master.TableStateManager.TableStateNotFoundException;
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
 import org.apache.hadoop.hbase.master.procedure.PeerProcedureInterface;
 import org.apache.hadoop.hbase.master.procedure.ProcedurePrepareLatch;
@@ -140,7 +140,7 @@ public abstract class AbstractPeerProcedure<TState> extends AbstractPeerNoLockPr
           return true;
         }
         Thread.sleep(SLEEP_INTERVAL_MS);
-      } catch (TableStateNotFoundException e) {
+      } catch (TableNotFoundException e) {
         return false;
       } catch (InterruptedException e) {
         throw (IOException) new InterruptedIOException(e.getMessage()).initCause(e);

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,10 +20,10 @@ package org.apache.hadoop.hbase.master.replication;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.TableState;
 import org.apache.hadoop.hbase.master.TableStateManager;
-import org.apache.hadoop.hbase.master.TableStateManager.TableStateNotFoundException;
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
 import org.apache.hadoop.hbase.master.procedure.ProcedurePrepareLatch;
 import org.apache.hadoop.hbase.master.procedure.ReopenTableRegionsProcedure;
@@ -125,7 +125,7 @@ public abstract class ModifyPeerProcedure extends AbstractPeerProcedure<PeerModi
           return false;
         }
         Thread.sleep(SLEEP_INTERVAL_MS);
-      } catch (TableStateNotFoundException e) {
+      } catch (TableNotFoundException e) {
         return false;
       } catch (InterruptedException e) {
         throw (IOException) new InterruptedIOException(e.getMessage()).initCause(e);

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

@@ -1,4 +1,4 @@
-/**
+/*
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -41,6 +41,6 @@ public class MetaLocationSyncer extends ClientZKSyncer {
 
   @Override
   Collection<String> getNodesToWatch() {
-    return watcher.getZNodePaths().metaReplicaZNodes.values();
+    return watcher.getZNodePaths().getMetaReplicaZNodes();
   }
-}
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -744,9 +744,14 @@ public class HRegionServer extends HasThread implements
 
   protected TableDescriptors getFsTableDescriptors() throws IOException {
     return new FSTableDescriptors(this.conf,
-      this.fs, this.rootDir, !canUpdateTableDescriptor(), false, getMetaTableObserver());
+      this.fs, this.rootDir, !canUpdateTableDescriptor(), false);
   }
 
+  /**
+   * @deprecated Since 2.3.0. Not needed anymore. Was used by Master to pass in replication
+   *   setting on hbase:meta construction. To be removed in hbase4.
+   */
+  @Deprecated
   protected Function<TableDescriptorBuilder, TableDescriptorBuilder> getMetaTableObserver() {
     return null;
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/RejectReplicationRequestStateChecker.java

@@ -1,4 +1,6 @@
-/**
+/*
+ * Copyright The Apache Software Foundation
+ *
  * 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
@@ -22,6 +24,7 @@ import java.util.function.BiPredicate;
 import org.apache.hadoop.hbase.replication.SyncReplicationState;
 import org.apache.yetus.audience.InterfaceAudience;
 
+
 /**
  * Check whether we need to reject the replication request from source cluster.
  */

hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -24,7 +24,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Function;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -99,10 +98,7 @@ public class FSTableDescriptors implements TableDescriptors {
   // TODO.
   private final Map<TableName, TableDescriptor> cache = new ConcurrentHashMap<>();
 
-  /**
+  private final Configuration configuration;
-   * Table descriptor for <code>hbase:meta</code> catalog table
-   */
-  private final TableDescriptor metaTableDescriptor;
 
   /**
    * Construct a FSTableDescriptors instance using the hbase root dir of the given
@@ -123,30 +119,22 @@ public class FSTableDescriptors implements TableDescriptors {
    *                   operations; i.e. on remove, we do not do delete in fs.
    */
   public FSTableDescriptors(final Configuration conf, final FileSystem fs,
-                            final Path rootdir, final boolean fsreadonly, final boolean usecache) throws IOException {
+      final Path rootdir, final boolean fsreadonly, final boolean usecache) throws IOException {
-    this(conf, fs, rootdir, fsreadonly, usecache, null);
-  }
-
-  /**
-   * @param fsreadonly True if we are read-only when it comes to filesystem
-   *                   operations; i.e. on remove, we do not do delete in fs.
-   * @param metaObserver Used by HMaster. It need to modify the META_REPLICAS_NUM for meta table descriptor.
-   *                     see HMaster#finishActiveMasterInitialization
-   *                     TODO: This is a workaround. Should remove this ugly code...
-   */
-  public FSTableDescriptors(final Configuration conf, final FileSystem fs,
-                            final Path rootdir, final boolean fsreadonly, final boolean usecache,
-                            Function<TableDescriptorBuilder, TableDescriptorBuilder> metaObserver) throws IOException {
     this.fs = fs;
     this.rootdir = rootdir;
     this.fsreadonly = fsreadonly;
     this.usecache = usecache;
-    this.metaTableDescriptor = metaObserver == null ? createMetaTableDescriptor(conf)
+    this.configuration = conf;
-          : metaObserver.apply(createMetaTableDescriptorBuilder(conf)).build();
   }
 
+  /**
+   * Should be private
+   * @deprecated Since 2.3.0. Should be for internal use only. Used by testing.
+   */
+  @Deprecated
   @VisibleForTesting
-  public static TableDescriptorBuilder createMetaTableDescriptorBuilder(final Configuration conf) throws IOException {
+  public static TableDescriptorBuilder createMetaTableDescriptorBuilder(final Configuration conf)
+      throws IOException {
     // TODO We used to set CacheDataInL1 for META table. When we have BucketCache in file mode, now
     // the META table data goes to File mode BC only. Test how that affect the system. If too much,
     // we have to rethink about adding back the setCacheDataInL1 for META table CFs.
@@ -191,7 +179,10 @@ public class FSTableDescriptors implements TableDescriptors {
         .build())
       .setCoprocessor(CoprocessorDescriptorBuilder.newBuilder(
         MultiRowMutationEndpoint.class.getName())
-        .setPriority(Coprocessor.PRIORITY_SYSTEM).build());
+        .setPriority(Coprocessor.PRIORITY_SYSTEM)
+        .build())
+        .setRegionReplication(conf.getInt(HConstants.META_REPLICAS_NUM,
+            HConstants.DEFAULT_META_REPLICA_NUM));
   }
 
   @VisibleForTesting
@@ -228,16 +219,11 @@ public class FSTableDescriptors implements TableDescriptors {
   public TableDescriptor get(final TableName tablename)
   throws IOException {
     invocations++;
-    if (TableName.META_TABLE_NAME.equals(tablename)) {
+    // If some one tries to get the descriptor for
-      cachehits++;
-      return metaTableDescriptor;
-    }
-    // hbase:meta is already handled. If some one tries to get the descriptor for
     // .logs, .oldlogs or .corrupt throw an exception.
     if (HConstants.HBASE_NON_USER_TABLE_DIRS.contains(tablename.getNameAsString())) {
-       throw new IOException("No descriptor found for non table = " + tablename);
+      throw new IOException("No descriptor found for non table = " + tablename);
     }
-
     if (usecache) {
       // Look in cache of descriptors.
       TableDescriptor cachedtdm = this.cache.get(tablename);
@@ -246,24 +232,27 @@ public class FSTableDescriptors implements TableDescriptors {
         return cachedtdm;
       }
     }
-    TableDescriptor tdmt = null;
+    TableDescriptor td = null;
     try {
-      tdmt = getTableDescriptorFromFs(fs, rootdir, tablename);
+      td = getTableDescriptorFromFs(fs, rootdir, tablename);
     } catch (NullPointerException e) {
-      LOG.debug("Exception during readTableDecriptor. Current table name = "
+      LOG.debug("Exception during readTableDecriptor; tableName={}", tablename, e);
-          + tablename, e);
     } catch (TableInfoMissingException e) {
-      // ignore. This is regular operation
+      if (TableName.isMetaTableName(tablename)) {
+        // If we tried to access hbase:meta and it not there, create it.
+        td = createMetaTableDescriptor(this.configuration);
+        LOG.info("Creating new hbase:meta table default descriptor/schema {}", td);
+      }
     } catch (IOException ioe) {
       LOG.debug("Exception during readTableDecriptor. Current table name = "
           + tablename, ioe);
     }
     // last HTD written wins
-    if (usecache && tdmt != null) {
+    if (usecache && td != null) {
-      this.cache.put(tablename, tdmt);
+      this.cache.put(tablename, td);
     }
 
-    return tdmt;
+    return td;
   }
 
   /**
@@ -273,16 +262,21 @@ public class FSTableDescriptors implements TableDescriptors {
   public Map<String, TableDescriptor> getAll()
   throws IOException {
     Map<String, TableDescriptor> tds = new TreeMap<>();
-
     if (fsvisited && usecache) {
+      if (this.cache.get(TableName.META_TABLE_NAME) == null) {
+        // This get will create hbase:meta if it does not exist. Will also populate cache.
+        get(TableName.META_TABLE_NAME);
+      }
       for (Map.Entry<TableName, TableDescriptor> entry: this.cache.entrySet()) {
         tds.put(entry.getKey().getNameWithNamespaceInclAsString(), entry.getValue());
       }
-      // add hbase:meta to the response
-      tds.put(this.metaTableDescriptor.getTableName().getNameAsString(), metaTableDescriptor);
     } else {
       LOG.trace("Fetching table descriptors from the filesystem.");
       boolean allvisited = true;
+      // Add hbase:meta descriptor. The get will create hbase:meta in fs if doesn't
+      // exist. FSUtils listing table names in fs skip meta dirs. TODO: Fill out
+      // FSUtils with methods to get userspace tables and system tables.
+      tds.put(TableName.META_TABLE_NAME.toString(), get(TableName.META_TABLE_NAME));
       for (Path d : FSUtils.getTableDirs(fs, rootdir)) {
         TableDescriptor htd = null;
         try {
@@ -336,14 +330,9 @@ public class FSTableDescriptors implements TableDescriptors {
     if (fsreadonly) {
       throw new NotImplementedException("Cannot add a table descriptor - in read only mode");
     }
-    TableName tableName = htd.getTableName();
+    if (HConstants.HBASE_NON_USER_TABLE_DIRS.contains(htd.getTableName().getNameAsString())) {
-    if (TableName.META_TABLE_NAME.equals(tableName)) {
+      throw new NotImplementedException("Cannot add Descriptor for reserved subdirectory name: " +
-      throw new NotImplementedException(HConstants.NOT_IMPLEMENTED);
+          htd.getTableName().getNameAsString());
-    }
-    if (HConstants.HBASE_NON_USER_TABLE_DIRS.contains(tableName.getNameAsString())) {
-      throw new NotImplementedException(
-          "Cannot add a table descriptor for a reserved subdirectory name: "
-              + htd.getTableName().getNameAsString());
     }
     updateTableDescriptor(htd);
   }
@@ -369,26 +358,6 @@ public class FSTableDescriptors implements TableDescriptors {
     return descriptor;
   }
 
-  /**
-   * Checks if a current table info file exists for the given table
-   *
-   * @param tableName name of table
-   * @return true if exists
-   * @throws IOException
-   */
-  public boolean isTableInfoExists(TableName tableName) throws IOException {
-    return getTableInfoPath(tableName) != null;
-  }
-
-  /**
-   * Find the most current table info file for the given table in the hbase root directory.
-   * @return The file status of the current table info file or null if it does not exist
-   */
-  private FileStatus getTableInfoPath(final TableName tableName) throws IOException {
-    Path tableDir = getTableDir(tableName);
-    return getTableInfoPath(tableDir);
-  }
-
   private FileStatus getTableInfoPath(Path tableDir)
   throws IOException {
     return getTableInfoPath(fs, tableDir, !fsreadonly);
@@ -403,7 +372,6 @@ public class FSTableDescriptors implements TableDescriptors {
    * were sequence numbers).
    *
    * @return The file status of the current table info file or null if it does not exist
-   * @throws IOException
    */
   public static FileStatus getTableInfoPath(FileSystem fs, Path tableDir)
   throws IOException {
@@ -421,7 +389,6 @@ public class FSTableDescriptors implements TableDescriptors {
    * older files.
    *
    * @return The file status of the current table info file or null if none exist
-   * @throws IOException
    */
   private static FileStatus getTableInfoPath(FileSystem fs, Path tableDir, boolean removeOldFiles)
   throws IOException {
@@ -609,21 +576,6 @@ public class FSTableDescriptors implements TableDescriptors {
     return p;
   }
 
-  /**
-   * Deletes all the table descriptor files from the file system.
-   * Used in unit tests only.
-   * @throws NotImplementedException if in read only mode
-   */
-  public void deleteTableDescriptorIfExists(TableName tableName) throws IOException {
-    if (fsreadonly) {
-      throw new NotImplementedException("Cannot delete a table descriptor - in read only mode");
-    }
-
-    Path tableDir = getTableDir(tableName);
-    Path tableInfoDir = new Path(tableDir, TABLEINFO_DIR);
-    deleteTableDescriptorFiles(fs, tableInfoDir, Integer.MAX_VALUE);
-  }
-
   /**
    * Deletes files matching the table info file pattern within the given directory
    * whose sequenceId is at most the given max sequenceId.
@@ -760,6 +712,27 @@ public class FSTableDescriptors implements TableDescriptors {
     if (fsreadonly) {
       throw new NotImplementedException("Cannot create a table descriptor - in read only mode");
     }
+    return createTableDescriptorForTableDirectory(this.fs, tableDir, htd, forceCreation);
+  }
+
+  /**
+   * Create a new TableDescriptor in the specified table directory and filesystem. Happens when we
+   * create a new table or snapshot a table. This method doesn't require creationg of an
+   * {@link FSTableDescriptors} instance so it takes a bunch of arguments. Users of the method
+   * above used to create an FSTableDescriptors instance just to run the method. That was fine
+   * until construction started expecting to be able to read the hbase:meta schema. Snapshotting
+   * to some random dir would fail construction if no hbase:meta schema available.
+   * @param fs Filesystem to write to. Snapshot can set it to other than that of running system.
+   * @param tableDir table directory under which we should write the file
+   * @param htd description of the table to write
+   * @param forceCreation if <tt>true</tt>,then even if previous table descriptor is present it will
+   *          be overwritten
+   * @return <tt>true</tt> if the we successfully created the file, <tt>false</tt> if the file
+   *         already exists and we weren't forcing the descriptor creation.
+   * @throws IOException if a filesystem error occurs
+   */
+  public static boolean createTableDescriptorForTableDirectory(FileSystem fs, Path tableDir,
+      TableDescriptor htd, boolean forceCreation) throws IOException {
     FileStatus status = getTableInfoPath(fs, tableDir);
     if (status != null) {
       LOG.debug("Current path=" + status.getPath());
@@ -775,6 +748,5 @@ public class FSTableDescriptors implements TableDescriptors {
     Path p = writeTableDescriptor(fs, htd, tableDir, status);
     return p != null;
   }
-
 }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtility.java

@@ -121,7 +121,6 @@ import org.apache.hadoop.hbase.security.visibility.VisibilityLabelsCache;
 import org.apache.hadoop.hbase.trace.TraceUtil;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.CommonFSUtils;
-import org.apache.hadoop.hbase.util.FSTableDescriptors;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.JVMClusterUtil;
 import org.apache.hadoop.hbase.util.JVMClusterUtil.MasterThread;
@@ -157,6 +156,7 @@ import org.apache.hbase.thirdparty.com.google.common.io.Closeables;
 
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 
+
 /**
  * Facility for testing HBase. Replacement for
  * old HBaseTestCase and HBaseClusterTestCase functionality.
@@ -494,17 +494,6 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
     return new Path(fs.getWorkingDirectory(), "test-data");
   }
 
-  /**
-   * @return META table descriptor
-   */
-  public TableDescriptorBuilder getMetaTableDescriptorBuilder() {
-    try {
-      return FSTableDescriptors.createMetaTableDescriptorBuilder(conf);
-    } catch (IOException e) {
-      throw new RuntimeException("Unable to create META table descriptor", e);
-    }
-  }
-
   /**
    * Returns a Path in the test filesystem, obtained from {@link #getTestFileSystem()}
    * to write temporary test data. Call this method after setting up the mini dfs cluster

hbase-server/src/test/java/org/apache/hadoop/hbase/TestHBaseMetaEdit.java

@@ -0,0 +1,109 @@
+/*
+ * 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;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hbase.client.Admin;
+import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
+import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
+import org.apache.hadoop.hbase.client.RegionInfoBuilder;
+import org.apache.hadoop.hbase.client.TableDescriptor;
+import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
+import org.apache.hadoop.hbase.regionserver.Region;
+import org.apache.hadoop.hbase.testclassification.LargeTests;
+import org.apache.hadoop.hbase.testclassification.MiscTests;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.rules.TestName;
+
+
+/**
+ * Test being able to edit hbase:meta.
+ */
+@Category({MiscTests.class, LargeTests.class})
+public class TestHBaseMetaEdit {
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+      HBaseClassTestRule.forClass(TestHBaseMetaEdit.class);
+  @Rule
+  public TestName name = new TestName();
+  private final static HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  @Before
+  public void before() throws Exception {
+    UTIL.startMiniCluster();
+  }
+
+  @After
+  public void after() throws Exception {
+    UTIL.shutdownMiniCluster();
+  }
+
+  /**
+   * Set versions, set HBASE-16213 indexed block encoding, and add a column family.
+   * Verify they are all in place by looking at TableDescriptor AND by checking
+   * what the RegionServer sees after opening Region.
+   */
+  @Test
+  public void testEditMeta() throws IOException {
+    Admin admin = UTIL.getAdmin();
+    admin.disableTable(TableName.META_TABLE_NAME);
+    TableDescriptor descriptor = admin.getDescriptor(TableName.META_TABLE_NAME);
+    ColumnFamilyDescriptor cfd = descriptor.getColumnFamily(HConstants.CATALOG_FAMILY);
+    byte [] extraColumnFamilyName = Bytes.toBytes("xtra");
+    ColumnFamilyDescriptor newCfd =
+        ColumnFamilyDescriptorBuilder.newBuilder(extraColumnFamilyName).build();
+    int oldVersions = cfd.getMaxVersions();
+    // Add '1' to current versions count.
+    cfd = ColumnFamilyDescriptorBuilder.newBuilder(cfd).setMaxVersions(oldVersions + 1).
+        setConfiguration(ColumnFamilyDescriptorBuilder.DATA_BLOCK_ENCODING,
+            DataBlockEncoding.ROW_INDEX_V1.toString()).build();
+    admin.modifyColumnFamily(TableName.META_TABLE_NAME, cfd);
+    admin.addColumnFamily(TableName.META_TABLE_NAME, newCfd);
+    descriptor = admin.getDescriptor(TableName.META_TABLE_NAME);
+    // Assert new max versions is == old versions plus 1.
+    assertEquals(oldVersions + 1,
+        descriptor.getColumnFamily(HConstants.CATALOG_FAMILY).getMaxVersions());
+    admin.enableTable(TableName.META_TABLE_NAME);
+    descriptor = admin.getDescriptor(TableName.META_TABLE_NAME);
+    // Assert new max versions is == old versions plus 1.
+    assertEquals(oldVersions + 1,
+        descriptor.getColumnFamily(HConstants.CATALOG_FAMILY).getMaxVersions());
+    assertTrue(descriptor.getColumnFamily(newCfd.getName()) != null);
+    String encoding = descriptor.getColumnFamily(HConstants.CATALOG_FAMILY).getConfiguration().
+        get(ColumnFamilyDescriptorBuilder.DATA_BLOCK_ENCODING);
+    assertEquals(encoding, DataBlockEncoding.ROW_INDEX_V1.toString());
+    Region r = UTIL.getHBaseCluster().getRegionServer(0).
+        getRegion(RegionInfoBuilder.FIRST_META_REGIONINFO.getEncodedName());
+    assertEquals(oldVersions + 1,
+        r.getStore(HConstants.CATALOG_FAMILY).getColumnFamilyDescriptor().getMaxVersions());
+    encoding = r.getStore(HConstants.CATALOG_FAMILY).getColumnFamilyDescriptor().
+        getConfigurationValue(ColumnFamilyDescriptorBuilder.DATA_BLOCK_ENCODING);
+    assertEquals(encoding, DataBlockEncoding.ROW_INDEX_V1.toString());
+    assertTrue(r.getStore(extraColumnFamilyName) != null);
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin2.java

@@ -44,7 +44,6 @@ import org.apache.hadoop.hbase.TableNotEnabledException;
 import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.UnknownRegionException;
 import org.apache.hadoop.hbase.Waiter.Predicate;
-import org.apache.hadoop.hbase.constraint.ConstraintException;
 import org.apache.hadoop.hbase.master.HMaster;
 import org.apache.hadoop.hbase.master.assignment.AssignmentManager;
 import org.apache.hadoop.hbase.regionserver.HRegion;
@@ -504,22 +503,6 @@ public class TestAdmin2 extends TestAdminBase {
     return regionServer;
   }
 
-  @Test
-  public void testDisableCatalogTable() throws Exception {
-    try {
-      ADMIN.disableTable(TableName.META_TABLE_NAME);
-      fail("Expected to throw ConstraintException");
-    } catch (ConstraintException e) {
-    }
-    // Before the fix for HBASE-6146, the below table creation was failing as the hbase:meta table
-    // actually getting disabled by the disableTable() call.
-    HTableDescriptor htd =
-        new HTableDescriptor(TableName.valueOf(Bytes.toBytes(name.getMethodName())));
-    HColumnDescriptor hcd = new HColumnDescriptor(Bytes.toBytes("cf1"));
-    htd.addFamily(hcd);
-    TEST_UTIL.getAdmin().createTable(htd);
-  }
-
   @Test
   public void testIsEnabledOrDisabledOnUnknownTable() throws Exception {
     try {

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

@@ -1,4 +1,4 @@
-/**
+/*
  * 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

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableAdminApi2.java

@@ -39,7 +39,6 @@ import java.util.Set;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
 
 /**
  * Class to test asynchronous table admin operations
@@ -54,18 +53,6 @@ public class TestAsyncTableAdminApi2 extends TestAsyncAdminBase {
   public static final HBaseClassTestRule CLASS_RULE =
       HBaseClassTestRule.forClass(TestAsyncTableAdminApi2.class);
 
-  @Test
-  public void testDisableCatalogTable() throws Exception {
-    try {
-      this.admin.disableTable(TableName.META_TABLE_NAME).join();
-      fail("Expected to throw ConstraintException");
-    } catch (Exception e) {
-    }
-    // Before the fix for HBASE-6146, the below table creation was failing as the hbase:meta table
-    // actually getting disabled by the disableTable() call.
-    createTableWithDefaultConf(tableName);
-  }
-
   @Test
   public void testAddColumnFamily() throws Exception {
     // Create a table with two families

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableAdminApi3.java

@@ -18,12 +18,9 @@
 package org.apache.hadoop.hbase.client;
 
 import static org.apache.hadoop.hbase.TableName.META_TABLE_NAME;
-import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -32,7 +29,6 @@ import java.util.Optional;
 import java.util.concurrent.ExecutionException;
 import java.util.regex.Pattern;
 import org.apache.hadoop.hbase.AsyncMetaTableAccessor;
-import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.TableName;
@@ -201,14 +197,6 @@ public class TestAsyncTableAdminApi3 extends TestAsyncAdminBase {
       ok = false;
     }
     assertTrue(ok);
-    // meta table can not be disabled.
-    try {
-      admin.disableTable(TableName.META_TABLE_NAME).get();
-      fail("meta table can not be disabled");
-    } catch (ExecutionException e) {
-      Throwable cause = e.getCause();
-      assertThat(cause, instanceOf(DoNotRetryIOException.class));
-    }
   }
 
   @Test

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

@@ -147,6 +147,13 @@ public class TestMetaWithReplicas {
   public void testMetaHTDReplicaCount() throws Exception {
     assertEquals(3,
       TEST_UTIL.getAdmin().getDescriptor(TableName.META_TABLE_NAME).getRegionReplication());
+    try (AsyncConnection connection =
+             ConnectionFactory.createAsyncConnection(TEST_UTIL.getConfiguration()).get()) {
+      AsyncTable t = connection.getTable(TableName.META_TABLE_NAME);
+      List<HRegionLocation> rls =
+          t.getRegionLocator().getRegionLocations(HConstants.EMPTY_START_ROW, true).get();
+      assertEquals(3, rls.size());
+    }
   }
 
   @Test

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestClusterId.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestGetClosestAtOrBefore.java

@@ -47,6 +47,7 @@ import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.RegionServerTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.apache.hadoop.hbase.util.FSTableDescriptors;
 import org.apache.hadoop.hbase.wal.WAL;
 import org.junit.ClassRule;
 import org.junit.Rule;
@@ -87,8 +88,10 @@ public class TestGetClosestAtOrBefore  {
   public void testUsingMetaAndBinary() throws IOException {
     FileSystem filesystem = FileSystem.get(conf);
     Path rootdir = UTIL.getDataTestDirOnTestFS();
+
     // Up flush size else we bind up when we use default catalog flush of 16k.
-    TableDescriptorBuilder metaBuilder = UTIL.getMetaTableDescriptorBuilder()
+    TableDescriptorBuilder metaBuilder =
+        FSTableDescriptors.createMetaTableDescriptorBuilder(UTIL.getConfiguration())
             .setMemStoreFlushSize(64 * 1024 * 1024);
 
     HRegion mr = HBaseTestingUtility.createRegionAndWAL(HRegionInfo.FIRST_META_REGIONINFO,

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestLogRollingNoCluster.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -37,6 +37,7 @@ import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.RegionServerTests;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSTableDescriptors;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.hbase.wal.WAL;
@@ -77,8 +78,6 @@ public class TestLogRollingNoCluster {
   /**
    * Spin up a bunch of threads and have them all append to a WAL.  Roll the
    * WAL frequently to try and trigger NPE.
-   * @throws IOException
-   * @throws InterruptedException
    */
   @Test
   public void testContendedLogRolling() throws Exception {
@@ -161,7 +160,8 @@ public class TestLogRollingNoCluster {
           byte[] bytes = Bytes.toBytes(i);
           edit.add(new KeyValue(bytes, bytes, bytes, now, EMPTY_1K_ARRAY));
           RegionInfo hri = RegionInfoBuilder.FIRST_META_REGIONINFO;
-          TableDescriptor htd = TEST_UTIL.getMetaTableDescriptorBuilder().build();
+          TableDescriptor htd =
+              FSTableDescriptors.createMetaTableDescriptor(TEST_UTIL.getConfiguration());
           NavigableMap<byte[], Integer> scopes = new TreeMap<>(Bytes.BYTES_COMPARATOR);
           for(byte[] fam : htd.getColumnFamilyNames()) {
             scopes.put(fam, 0);

hbase-server/src/test/java/org/apache/hadoop/hbase/util/TestFSTableDescriptors.java

@@ -322,7 +322,9 @@ public class TestFSTableDescriptors {
     }
 
     Map<String, TableDescriptor> tables = tds.getAll();
-    assertEquals(4, tables.size());
+    assertEquals(5, tables.size());
+    // Remove because it messes up below order test.
+    tables.remove(TableName.META_TABLE_NAME.toString());
 
     String[] tableNamesOrdered =
         new String[] { "bar:foo", "default:bar", "default:foo", "foo:bar" };
@@ -368,6 +370,9 @@ public class TestFSTableDescriptors {
 
     for (Map.Entry<String, TableDescriptor> entry: nonchtds.getAll().entrySet()) {
       String t = (String) entry.getKey();
+      if (t.equals(TableName.META_TABLE_NAME.toString())) {
+        continue;
+      }
       TableDescriptor nchtd = entry.getValue();
       assertTrue("expected " + htd.toString() +
                    " got: " + chtds.get(TableName.valueOf(t)).toString(),

hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/MetaTableLocator.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -61,14 +61,6 @@ public final class MetaTableLocator {
   private MetaTableLocator() {
   }
 
-  /**
-   * Checks if the meta region location is available.
-   * @return true if meta region location is available, false if not
-   */
-  public static boolean isLocationAvailable(ZKWatcher zkw) {
-    return getMetaRegionLocation(zkw) != null;
-  }
-
   /**
    * @param zkw ZooKeeper watcher to be used
    * @return meta table regions and their locations.
@@ -266,7 +258,7 @@ public final class MetaTableLocator {
   }
 
   /**
-   * Load the meta region state from the meta server ZNode.
+   * Load the meta region state from the meta region server ZNode.
    *
    * @param zkw reference to the {@link ZKWatcher} which also contains configuration and operation
    * @param replicaId the ID of the replica
@@ -306,10 +298,8 @@ public final class MetaTableLocator {
     if (serverName == null) {
       state = RegionState.State.OFFLINE;
     }
-    return new RegionState(
+    return new RegionState(RegionReplicaUtil.getRegionInfoForReplica(
-        RegionReplicaUtil.getRegionInfoForReplica(
+        RegionInfoBuilder.FIRST_META_REGIONINFO, replicaId), state, serverName);
-            RegionInfoBuilder.FIRST_META_REGIONINFO, replicaId),
-        state, serverName);
   }
 
   /**

hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java

@@ -2057,7 +2057,7 @@ public final class ZKUtil {
       " byte(s) of data from znode " + znode +
       (watcherSet? " and set watcher; ": "; data=") +
       (data == null? "null": data.length == 0? "empty": (
-          znode.startsWith(zkw.getZNodePaths().metaZNodePrefix)?
+          zkw.getZNodePaths().isMetaZNodePrefix(znode)?
             getServerNameOrEmptyString(data):
           znode.startsWith(zkw.getZNodePaths().backupMasterAddressesZNode)?
             getServerNameOrEmptyString(data):