/**
    *
    * 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 java.io.Closeable;
  import java.io.IOException;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.Future;
  import java.util.regex.Pattern;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.Abortable;
  import org.apache.hadoop.hbase.ClusterStatus;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.NamespaceDescriptor;
  import org.apache.hadoop.hbase.ProcedureInfo;
  import org.apache.hadoop.hbase.ServerName;
  import org.apache.hadoop.hbase.TableExistsException;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.TableNotFoundException;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel;
  import org.apache.hadoop.hbase.protobuf.generated.AdminProtos;
  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProtos;
  import org.apache.hadoop.hbase.quotas.QuotaFilter;
  import org.apache.hadoop.hbase.quotas.QuotaRetriever;
  import org.apache.hadoop.hbase.quotas.QuotaSettings;
  import org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;
  import org.apache.hadoop.hbase.snapshot.HBaseSnapshotException;
  import org.apache.hadoop.hbase.snapshot.RestoreSnapshotException;
  import org.apache.hadoop.hbase.snapshot.SnapshotCreationException;
  import org.apache.hadoop.hbase.snapshot.UnknownSnapshotException;
  import org.apache.hadoop.hbase.util.Pair;
  
  /**
   * The administrative API for HBase. Obtain an instance from an {@link Connection#getAdmin()} and
   * call {@link #close()} afterwards.
   * <p>Admin can be used to create, drop, list, enable and disable tables, add and drop table
   * column families and other administrative operations.
   *
   * @see ConnectionFactory
   * @see Connection
   * @see Table
   * @since 0.99.0
   */
  @InterfaceAudience.Public
  @InterfaceStability.Evolving
  public interface Admin extends Abortable, Closeable {
    int getOperationTimeout();
  
    @Override
    void abort(String why, Throwable e);
  
    @Override
    boolean isAborted();
  
    /**
     * @return Connection used by this object.
     */
    Connection getConnection();
  
    /**
     * @param tableName Table to check.
     * @return True if table exists already.
     * @throws IOException
     */
    boolean tableExists(final TableName tableName) throws IOException;
  
    /**
     * List all the userspace tables.
     *
     * @return - returns an array of HTableDescriptors
     * @throws IOException if a remote or network exception occurs
     */
    HTableDescriptor[] listTables() throws IOException;
  
    /**
     * List all the userspace tables matching the given pattern.
    *
    * @param pattern The compiled regular expression to match against
    * @return - returns an array of HTableDescriptors
    * @throws IOException if a remote or network exception occurs
    * @see #listTables()
    */
   HTableDescriptor[] listTables(Pattern pattern) throws IOException;
 
   /**
    * List all the userspace tables matching the given regular expression.
    *
    * @param regex The regular expression to match against
    * @return - returns an array of HTableDescriptors
    * @throws IOException if a remote or network exception occurs
    * @see #listTables(java.util.regex.Pattern)
    */
   HTableDescriptor[] listTables(String regex) throws IOException;
 
   /**
    * List all the tables matching the given pattern.
    *
    * @param pattern The compiled regular expression to match against
    * @param includeSysTables False to match only against userspace tables
    * @return - returns an array of HTableDescriptors
    * @throws IOException if a remote or network exception occurs
    * @see #listTables()
    */
   HTableDescriptor[] listTables(Pattern pattern, boolean includeSysTables)
       throws IOException;
 
   /**
    * List all the tables matching the given pattern.
    *
    * @param regex The regular expression to match against
    * @param includeSysTables False to match only against userspace tables
    * @return - returns an array of HTableDescriptors
    * @throws IOException if a remote or network exception occurs
    * @see #listTables(java.util.regex.Pattern, boolean)
    */
   HTableDescriptor[] listTables(String regex, boolean includeSysTables)
       throws IOException;
 
   /**
    * List all of the names of userspace tables.
    *
    * @return TableName[] table names
    * @throws IOException if a remote or network exception occurs
    */
   TableName[] listTableNames() throws IOException;
 
   /**
    * List all of the names of userspace tables.
    * @param pattern The regular expression to match against
    * @return TableName[] table names
    * @throws IOException if a remote or network exception occurs
    */
   TableName[] listTableNames(Pattern pattern) throws IOException;
 
   /**
    * List all of the names of userspace tables.
    * @param regex The regular expression to match against
    * @return TableName[] table names
    * @throws IOException if a remote or network exception occurs
    */
   TableName[] listTableNames(String regex) throws IOException;
 
   /**
    * List all of the names of userspace tables.
    * @param pattern The regular expression to match against
    * @param includeSysTables False to match only against userspace tables
    * @return TableName[] table names
    * @throws IOException if a remote or network exception occurs
    */
   TableName[] listTableNames(final Pattern pattern, final boolean includeSysTables)
       throws IOException;
 
   /**
    * List all of the names of userspace tables.
    * @param regex The regular expression to match against
    * @param includeSysTables False to match only against userspace tables
    * @return TableName[] table names
    * @throws IOException if a remote or network exception occurs
    */
   TableName[] listTableNames(final String regex, final boolean includeSysTables)
       throws IOException;
 
   /**
    * Method for getting the tableDescriptor
    *
    * @param tableName as a {@link TableName}
    * @return the tableDescriptor
    * @throws org.apache.hadoop.hbase.TableNotFoundException
    * @throws IOException if a remote or network exception occurs
    */
   HTableDescriptor getTableDescriptor(final TableName tableName)
       throws TableNotFoundException, IOException;
 
   /**
    * Creates a new table. Synchronous operation.
    *
    * @param desc table descriptor for table
    * @throws IllegalArgumentException if the table name is reserved
    * @throws MasterNotRunningException if master is not running
    * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent
    * threads, the table may have been created between test-for-existence and attempt-at-creation).
    * @throws IOException if a remote or network exception occurs
    */
   void createTable(HTableDescriptor desc) throws IOException;
 
   /**
    * Creates a new table with the specified number of regions.  The start key specified will become
    * the end key of the first region of the table, and the end key specified will become the start
    * key of the last region of the table (the first region has a null start key and the last region
    * has a null end key). BigInteger math will be used to divide the key range specified into enough
    * segments to make the required number of total regions. Synchronous operation.
    *
    * @param desc table descriptor for table
    * @param startKey beginning of key range
    * @param endKey end of key range
    * @param numRegions the total number of regions to create
    * @throws IllegalArgumentException if the table name is reserved
    * @throws MasterNotRunningException if master is not running
    * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent
    * threads, the table may have been created between test-for-existence and attempt-at-creation).
    * @throws IOException
    */
   void createTable(HTableDescriptor desc, byte[] startKey, byte[] endKey, int numRegions)
       throws IOException;
 
   /**
    * Creates a new table with an initial set of empty regions defined by the specified split keys.
    * The total number of regions created will be the number of split keys plus one. Synchronous
    * operation. Note : Avoid passing empty split key.
    *
    * @param desc table descriptor for table
    * @param splitKeys array of split keys for the initial regions of the table
    * @throws IllegalArgumentException if the table name is reserved, if the split keys are repeated
    * and if the split key has empty byte array.
    * @throws MasterNotRunningException if master is not running
    * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent
    * threads, the table may have been created between test-for-existence and attempt-at-creation).
    * @throws IOException
    */
   void createTable(final HTableDescriptor desc, byte[][] splitKeys) throws IOException;
 
   /**
    * Creates a new table but does not block and wait for it to come online. Asynchronous operation.
    * To check if the table exists, use {@link #isTableAvailable} -- it is not safe to create an
    * HTable instance to this table before it is available. Note : Avoid passing empty split key.
    *
    * @param desc table descriptor for table
    * @throws IllegalArgumentException Bad table name, if the split keys are repeated and if the
    * split key has empty byte array.
    * @throws MasterNotRunningException if master is not running
    * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent
    * threads, the table may have been created between test-for-existence and attempt-at-creation).
    * @throws IOException
    */
   void createTableAsync(final HTableDescriptor desc, final byte[][] splitKeys) throws IOException;
 
   /**
    * Deletes a table. Synchronous operation.
    *
    * @param tableName name of table to delete
    * @throws IOException if a remote or network exception occurs
    */
   void deleteTable(final TableName tableName) throws IOException;
 
   /**
    * Deletes tables matching the passed in pattern and wait on completion. Warning: Use this method
    * carefully, there is no prompting and the effect is immediate. Consider using {@link
    * #listTables(java.lang.String)} and {@link #deleteTable(org.apache.hadoop.hbase.TableName)}
    *
    * @param regex The regular expression to match table names against
    * @return Table descriptors for tables that couldn't be deleted
    * @throws IOException
    * @see #deleteTables(java.util.regex.Pattern)
    * @see #deleteTable(org.apache.hadoop.hbase.TableName)
    */
   HTableDescriptor[] deleteTables(String regex) throws IOException;
 
   /**
    * Delete tables matching the passed in pattern and wait on completion. Warning: Use this method
    * carefully, there is no prompting and the effect is immediate. Consider using {@link
    * #listTables(java.util.regex.Pattern) } and
    * {@link #deleteTable(org.apache.hadoop.hbase.TableName)}
    *
    * @param pattern The pattern to match table names against
    * @return Table descriptors for tables that couldn't be deleted
    * @throws IOException
    */
   HTableDescriptor[] deleteTables(Pattern pattern) throws IOException;
 
   /**
    * Truncate a table.
    * Synchronous operation.
    *
    * @param tableName name of table to truncate
    * @param preserveSplits True if the splits should be preserved
    * @throws IOException if a remote or network exception occurs
    */
   public void truncateTable(final TableName tableName, final boolean preserveSplits)
       throws IOException;
 
   /**
    * Enable a table.  May timeout.  Use {@link #enableTableAsync(org.apache.hadoop.hbase.TableName)}
    * and {@link #isTableEnabled(org.apache.hadoop.hbase.TableName)} instead. The table has to be in
    * disabled state for it to be enabled.
    *
    * @param tableName name of the table
    * @throws IOException if a remote or network exception occurs There could be couple types of
    * IOException TableNotFoundException means the table doesn't exist. TableNotDisabledException
    * means the table isn't in disabled state.
    * @see #isTableEnabled(org.apache.hadoop.hbase.TableName)
    * @see #disableTable(org.apache.hadoop.hbase.TableName)
    * @see #enableTableAsync(org.apache.hadoop.hbase.TableName)
    */
   void enableTable(final TableName tableName) throws IOException;
 
   /**
    * Brings a table on-line (enables it).  Method returns immediately though enable of table may
    * take some time to complete, especially if the table is large (All regions are opened as part of
    * enabling process).  Check {@link #isTableEnabled(org.apache.hadoop.hbase.TableName)} to learn
    * when table is fully online.  If table is taking too long to online, check server logs.
    *
    * @param tableName
    * @throws IOException
    * @since 0.90.0
    */
   void enableTableAsync(final TableName tableName) throws IOException;
 
   /**
    * Enable tables matching the passed in pattern and wait on completion. Warning: Use this method
    * carefully, there is no prompting and the effect is immediate. Consider using {@link
    * #listTables(java.lang.String)} and {@link #enableTable(org.apache.hadoop.hbase.TableName)}
    *
    * @param regex The regular expression to match table names against
    * @throws IOException
    * @see #enableTables(java.util.regex.Pattern)
    * @see #enableTable(org.apache.hadoop.hbase.TableName)
    */
   HTableDescriptor[] enableTables(String regex) throws IOException;
 
   /**
    * Enable tables matching the passed in pattern and wait on completion. Warning: Use this method
    * carefully, there is no prompting and the effect is immediate. Consider using {@link
    * #listTables(java.util.regex.Pattern) } and
    * {@link #enableTable(org.apache.hadoop.hbase.TableName)}
    *
    * @param pattern The pattern to match table names against
    * @throws IOException
    */
   HTableDescriptor[] enableTables(Pattern pattern) throws IOException;
 
   /**
    * Starts the disable of a table.  If it is being served, the master will tell the servers to stop
    * serving it.  This method returns immediately. The disable of a table can take some time if the
    * table is large (all regions are closed as part of table disable operation). Call {@link
    * #isTableDisabled(org.apache.hadoop.hbase.TableName)} to check for when disable completes. If
    * table is taking too long to online, check server logs.
    *
    * @param tableName name of table
    * @throws IOException if a remote or network exception occurs
    * @see #isTableDisabled(org.apache.hadoop.hbase.TableName)
    * @see #isTableEnabled(org.apache.hadoop.hbase.TableName)
    * @since 0.90.0
    */
   void disableTableAsync(final TableName tableName) throws IOException;
 
   /**
    * Disable table and wait on completion.  May timeout eventually.  Use {@link
    * #disableTableAsync(org.apache.hadoop.hbase.TableName)} and
    * {@link #isTableDisabled(org.apache.hadoop.hbase.TableName)} instead. The table has to be in
    * enabled state for it to be disabled.
    *
    * @param tableName
    * @throws IOException There could be couple types of IOException TableNotFoundException means the
    * table doesn't exist. TableNotEnabledException means the table isn't in enabled state.
    */
   void disableTable(final TableName tableName) throws IOException;
 
   /**
    * Disable tables matching the passed in pattern and wait on completion. Warning: Use this method
    * carefully, there is no prompting and the effect is immediate. Consider using {@link
    * #listTables(java.lang.String)} and {@link #disableTable(org.apache.hadoop.hbase.TableName)}
    *
    * @param regex The regular expression to match table names against
    * @return Table descriptors for tables that couldn't be disabled
    * @throws IOException
    * @see #disableTables(java.util.regex.Pattern)
    * @see #disableTable(org.apache.hadoop.hbase.TableName)
    */
   HTableDescriptor[] disableTables(String regex) throws IOException;
 
   /**
    * Disable tables matching the passed in pattern and wait on completion. Warning: Use this method
    * carefully, there is no prompting and the effect is immediate. Consider using {@link
    * #listTables(java.util.regex.Pattern) } and
    * {@link #disableTable(org.apache.hadoop.hbase.TableName)}
    *
    * @param pattern The pattern to match table names against
    * @return Table descriptors for tables that couldn't be disabled
    * @throws IOException
    */
   HTableDescriptor[] disableTables(Pattern pattern) throws IOException;
 
   /**
    * @param tableName name of table to check
    * @return true if table is on-line
    * @throws IOException if a remote or network exception occurs
    */
   boolean isTableEnabled(TableName tableName) throws IOException;
 
   /**
    * @param tableName name of table to check
    * @return true if table is off-line
    * @throws IOException if a remote or network exception occurs
    */
   boolean isTableDisabled(TableName tableName) throws IOException;
 
   /**
    * @param tableName name of table to check
    * @return true if all regions of the table are available
    * @throws IOException if a remote or network exception occurs
    */
   boolean isTableAvailable(TableName tableName) throws IOException;
 
   /**
    * Use this api to check if the table has been created with the specified number of splitkeys
    * which was used while creating the given table. Note : If this api is used after a table's
    * region gets splitted, the api may return false.
    *
    * @param tableName name of table to check
    * @param splitKeys keys to check if the table has been created with all split keys
    * @throws IOException if a remote or network excpetion occurs
    */
   boolean isTableAvailable(TableName tableName, byte[][] splitKeys) throws IOException;
 
   /**
    * Get the status of alter command - indicates how many regions have received the updated schema
    * Asynchronous operation.
    *
    * @param tableName TableName instance
    * @return Pair indicating the number of regions updated Pair.getFirst() is the regions that are
    * yet to be updated Pair.getSecond() is the total number of regions of the table
    * @throws IOException if a remote or network exception occurs
    */
   Pair<Integer, Integer> getAlterStatus(final TableName tableName) throws IOException;
 
   /**
    * Get the status of alter command - indicates how many regions have received the updated schema
    * Asynchronous operation.
    *
    * @param tableName name of the table to get the status of
    * @return Pair indicating the number of regions updated Pair.getFirst() is the regions that are
    * yet to be updated Pair.getSecond() is the total number of regions of the table
    * @throws IOException if a remote or network exception occurs
    */
   Pair<Integer, Integer> getAlterStatus(final byte[] tableName) throws IOException;
 
   /**
    * Add a column to an existing table. Asynchronous operation.
    *
    * @param tableName name of the table to add column to
    * @param column column descriptor of column to be added
    * @throws IOException if a remote or network exception occurs
    */
   void addColumn(final TableName tableName, final HColumnDescriptor column) throws IOException;
 
   /**
    * Delete a column from a table. Asynchronous operation.
    *
    * @param tableName name of table
    * @param columnName name of column to be deleted
    * @throws IOException if a remote or network exception occurs
    */
   void deleteColumn(final TableName tableName, final byte[] columnName) throws IOException;
 
   /**
    * Modify an existing column family on a table. Asynchronous operation.
    *
    * @param tableName name of table
    * @param descriptor new column descriptor to use
    * @throws IOException if a remote or network exception occurs
    */
   void modifyColumn(final TableName tableName, final HColumnDescriptor descriptor)
       throws IOException;
 
   /**
    * Close a region. For expert-admins.  Runs close on the regionserver.  The master will not be
    * informed of the close.
    *
    * @param regionname region name to close
    * @param serverName If supplied, we'll use this location rather than the one currently in
    * <code>hbase:meta</code>
    * @throws IOException if a remote or network exception occurs
    */
   void closeRegion(final String regionname, final String serverName) throws IOException;
 
   /**
    * Close a region.  For expert-admins  Runs close on the regionserver.  The master will not be
    * informed of the close.
    *
    * @param regionname region name to close
    * @param serverName The servername of the regionserver.  If passed null we will use servername
    * found in the hbase:meta table. A server name is made of host, port and startcode.  Here is an
    * example: <code> host187.example.com,60020,1289493121758</code>
    * @throws IOException if a remote or network exception occurs
    */
   void closeRegion(final byte[] regionname, final String serverName) throws IOException;
 
   /**
    * For expert-admins. Runs close on the regionserver. Closes a region based on the encoded region
    * name. The region server name is mandatory. If the servername is provided then based on the
    * online regions in the specified regionserver the specified region will be closed. The master
    * will not be informed of the close. Note that the regionname is the encoded regionname.
    *
    * @param encodedRegionName The encoded region name; i.e. the hash that makes up the region name
    * suffix: e.g. if regionname is
    * <code>TestTable,0094429456,1289497600452.527db22f95c8a9e0116f0cc13c680396.</code>,
    * then the encoded region name is: <code>527db22f95c8a9e0116f0cc13c680396</code>.
    * @param serverName The servername of the regionserver. A server name is made of host, port and
    * startcode. This is mandatory. Here is an example:
    * <code> host187.example.com,60020,1289493121758</code>
    * @return true if the region was closed, false if not.
    * @throws IOException if a remote or network exception occurs
    */
   boolean closeRegionWithEncodedRegionName(final String encodedRegionName, final String serverName)
       throws IOException;
 
   /**
    * Close a region.  For expert-admins  Runs close on the regionserver.  The master will not be
    * informed of the close.
    *
    * @param sn
    * @param hri
    * @throws IOException
    */
   void closeRegion(final ServerName sn, final HRegionInfo hri) throws IOException;
 
   /**
    * Get all the online regions on a region server.
    */
   List<HRegionInfo> getOnlineRegions(final ServerName sn) throws IOException;
 
   /**
    * Flush a table. Synchronous operation.
    *
    * @param tableName table to flush
    * @throws IOException if a remote or network exception occurs
    */
   void flush(final TableName tableName) throws IOException;
 
   /**
    * Flush an individual region. Synchronous operation.
    *
    * @param regionName region to flush
    * @throws IOException if a remote or network exception occurs
    */
   void flushRegion(final byte[] regionName) throws IOException;
 
   /**
    * Compact a table. Asynchronous operation.
    *
    * @param tableName table to compact
    * @throws IOException if a remote or network exception occurs
    */
   void compact(final TableName tableName) throws IOException;
 
   /**
    * Compact an individual region. Asynchronous operation.
    *
    * @param regionName region to compact
    * @throws IOException if a remote or network exception occurs
    */
   void compactRegion(final byte[] regionName) throws IOException;
 
   /**
    * Compact a column family within a table. Asynchronous operation.
    *
    * @param tableName table to compact
    * @param columnFamily column family within a table
    * @throws IOException if a remote or network exception occurs
    */
   void compact(final TableName tableName, final byte[] columnFamily)
     throws IOException;
 
   /**
    * Compact a column family within a region. Asynchronous operation.
    *
    * @param regionName region to compact
    * @param columnFamily column family within a region
    * @throws IOException if a remote or network exception occurs
    */
   void compactRegion(final byte[] regionName, final byte[] columnFamily)
     throws IOException;
 
   /**
    * Major compact a table. Asynchronous operation.
    *
    * @param tableName table to major compact
    * @throws IOException if a remote or network exception occurs
    */
   void majorCompact(TableName tableName) throws IOException;
 
   /**
    * Major compact a table or an individual region. Asynchronous operation.
    *
    * @param regionName region to major compact
    * @throws IOException if a remote or network exception occurs
    */
   void majorCompactRegion(final byte[] regionName) throws IOException;
 
   /**
    * Major compact a column family within a table. Asynchronous operation.
    *
    * @param tableName table to major compact
    * @param columnFamily column family within a table
    * @throws IOException if a remote or network exception occurs
    */
   void majorCompact(TableName tableName, final byte[] columnFamily)
     throws IOException;
 
   /**
    * Major compact a column family within region. Asynchronous operation.
    *
    * @param regionName egion to major compact
    * @param columnFamily column family within a region
    * @throws IOException if a remote or network exception occurs
    */
   void majorCompactRegion(final byte[] regionName, final byte[] columnFamily)
     throws IOException;
 
   /**
    * Compact all regions on the region server
    * @param sn the region server name
    * @param major if it's major compaction
    * @throws IOException
    * @throws InterruptedException
    */
   public void compactRegionServer(final ServerName sn, boolean major)
     throws IOException, InterruptedException;
 
   /**
    * Move the region <code>r</code> to <code>dest</code>.
    *
    * @param encodedRegionName The encoded region name; i.e. the hash that makes up the region name
    * suffix: e.g. if regionname is
    * <code>TestTable,0094429456,1289497600452.527db22f95c8a9e0116f0cc13c680396.</code>,
    * then the encoded region name is: <code>527db22f95c8a9e0116f0cc13c680396</code>.
    * @param destServerName The servername of the destination regionserver.  If passed the empty byte
    * array we'll assign to a random server.  A server name is made of host, port and startcode.
    * Here is an example: <code> host187.example.com,60020,1289493121758</code>
    * @throws UnknownRegionException Thrown if we can't find a region named
    * <code>encodedRegionName</code>
    */
   void move(final byte[] encodedRegionName, final byte[] destServerName)
       throws IOException;
 
   /**
    * @param regionName Region name to assign.
    */
   void assign(final byte[] regionName)
       throws IOException;
 
   /**
    * Unassign a region from current hosting regionserver.  Region will then be assigned to a
    * regionserver chosen at random.  Region could be reassigned back to the same server.  Use {@link
    * #move(byte[], byte[])} if you want to control the region movement.
    *
    * @param regionName Region to unassign. Will clear any existing RegionPlan if one found.
    * @param force If true, force unassign (Will remove region from regions-in-transition too if
    * present. If results in double assignment use hbck -fix to resolve. To be used by experts).
    */
   void unassign(final byte[] regionName, final boolean force)
       throws IOException;
 
   /**
    * Offline specified region from master's in-memory state. It will not attempt to reassign the
    * region as in unassign. This API can be used when a region not served by any region server and
    * still online as per Master's in memory state. If this API is incorrectly used on active region
    * then master will loose track of that region. This is a special method that should be used by
    * experts or hbck.
    *
    * @param regionName Region to offline.
    * @throws IOException
    */
   void offline(final byte[] regionName) throws IOException;
 
   /**
    * Turn the load balancer on or off.
    *
    * @param synchronous If true, it waits until current balance() call, if outstanding, to return.
    * @return Previous balancer value
    */
   boolean setBalancerRunning(final boolean on, final boolean synchronous)
       throws IOException;
 
   /**
    * Invoke the balancer.  Will run the balancer and if regions to move, it will go ahead and do the
    * reassignments.  Can NOT run for various reasons.  Check logs.
    *
    * @return True if balancer ran, false otherwise.
    */
   boolean balancer() throws IOException;
 
   /**
    * Query the current state of the balancer
    *
    * @return true if the balancer is enabled, false otherwise.
    */
   boolean isBalancerEnabled() throws IOException;
 
   /**
    * Enable/Disable the catalog janitor
    *
    * @param enable if true enables the catalog janitor
    * @return the previous state
    */
   boolean enableCatalogJanitor(boolean enable) throws IOException;
 
   /**
    * Ask for a scan of the catalog table
    *
    * @return the number of entries cleaned
    */
   int runCatalogScan() throws IOException;
 
   /**
    * Query on the catalog janitor state (Enabled/Disabled?)
    *
    */
   boolean isCatalogJanitorEnabled() throws IOException;
 
   /**
    * Merge two regions. Asynchronous operation.
    *
    * @param encodedNameOfRegionA encoded name of region a
    * @param encodedNameOfRegionB encoded name of region b
    * @param forcible true if do a compulsory merge, otherwise we will only merge two adjacent
    * regions
    * @throws IOException
    */
   void mergeRegions(final byte[] encodedNameOfRegionA, final byte[] encodedNameOfRegionB,
       final boolean forcible) throws IOException;
 
   /**
    * Split a table. Asynchronous operation.
    *
    * @param tableName table to split
    * @throws IOException if a remote or network exception occurs
    */
   void split(final TableName tableName) throws IOException;
 
   /**
    * Split an individual region. Asynchronous operation.
    *
    * @param regionName region to split
    * @throws IOException if a remote or network exception occurs
    */
   void splitRegion(final byte[] regionName) throws IOException;
 
   /**
    * Split a table. Asynchronous operation.
    *
    * @param tableName table to split
    * @param splitPoint the explicit position to split on
    * @throws IOException if a remote or network exception occurs
    */
   void split(final TableName tableName, final byte[] splitPoint)
     throws IOException;
 
   /**
    * Split an individual region. Asynchronous operation.
    *
    * @param regionName region to split
    * @param splitPoint the explicit position to split on
    * @throws IOException if a remote or network exception occurs
    */
   void splitRegion(final byte[] regionName, final byte[] splitPoint)
     throws IOException;
 
   /**
    * Modify an existing table, more IRB friendly version. Asynchronous operation.  This means that
    * it may be a while before your schema change is updated across all of the table.
    *
    * @param tableName name of table.
    * @param htd modified description of the table
    * @throws IOException if a remote or network exception occurs
    */
   void modifyTable(final TableName tableName, final HTableDescriptor htd)
       throws IOException;
 
   /**
    * Shuts down the HBase cluster
    *
    * @throws IOException if a remote or network exception occurs
    */
   void shutdown() throws IOException;
 
   /**
    * Shuts down the current HBase master only. Does not shutdown the cluster.
    *
    * @throws IOException if a remote or network exception occurs
    * @see #shutdown()
    */
   void stopMaster() throws IOException;
 
   /**
    * Stop the designated regionserver
    *
    * @param hostnamePort Hostname and port delimited by a <code>:</code> as in
    * <code>example.org:1234</code>
    * @throws IOException if a remote or network exception occurs
    */
   void stopRegionServer(final String hostnamePort) throws IOException;
 
   /**
    * @return cluster status
    * @throws IOException if a remote or network exception occurs
    */
   ClusterStatus getClusterStatus() throws IOException;
 
   /**
    * @return Configuration used by the instance.
    */
   Configuration getConfiguration();
 
   /**
    * Create a new namespace
    *
    * @param descriptor descriptor which describes the new namespace
    * @throws IOException
    */
   void createNamespace(final NamespaceDescriptor descriptor)
       throws IOException;
 
   /**
    * Modify an existing namespace
    *
    * @param descriptor descriptor which describes the new namespace
    * @throws IOException
    */
   void modifyNamespace(final NamespaceDescriptor descriptor)
       throws IOException;
 
   /**
    * Delete an existing namespace. Only empty namespaces (no tables) can be removed.
    *
    * @param name namespace name
    * @throws IOException
    */
   void deleteNamespace(final String name) throws IOException;
 
   /**
    * Get a namespace descriptor by name
    *
    * @param name name of namespace descriptor
    * @return A descriptor
    * @throws IOException
    */
   NamespaceDescriptor getNamespaceDescriptor(final String name)
       throws IOException;
 
   /**
    * List available namespace descriptors
    *
    * @return List of descriptors
    * @throws IOException
    */
   NamespaceDescriptor[] listNamespaceDescriptors()
     throws IOException;
 
   /**
    * Get list of table descriptors by namespace
    *
    * @param name namespace name
    * @return A descriptor
    * @throws IOException
    */
   HTableDescriptor[] listTableDescriptorsByNamespace(final String name)
       throws IOException;
 
   /**
    * Get list of table names by namespace
    *
    * @param name namespace name
    * @return The list of table names in the namespace
    * @throws IOException
    */
   TableName[] listTableNamesByNamespace(final String name)
       throws IOException;
 
   /**
    * Get the regions of a given table.
    *
    * @param tableName the name of the table
    * @return List of {@link HRegionInfo}.
    * @throws IOException
    */
   List<HRegionInfo> getTableRegions(final TableName tableName)
     throws IOException;
 
   @Override
   void close() throws IOException;
 
   /**
    * Get tableDescriptors
    *
    * @param tableNames List of table names
    * @return HTD[] the tableDescriptor
    * @throws IOException if a remote or network exception occurs
    */
   HTableDescriptor[] getTableDescriptorsByTableName(List<TableName> tableNames)
     throws IOException;
 
   /**
    * Get tableDescriptors
    *
    * @param names List of table names
    * @return HTD[] the tableDescriptor
    * @throws IOException if a remote or network exception occurs
    */
   HTableDescriptor[] getTableDescriptors(List<String> names)
     throws IOException;
 
   /**
    * abort a procedure
    * @param procId ID of the procedure to abort
    * @param mayInterruptIfRunning if the proc completed at least one step, should it be aborted?
    * @return true if aborted, false if procedure already completed or does not exist
    * @throws IOException
    */
   boolean abortProcedure(
       final long procId,
       final boolean mayInterruptIfRunning) throws IOException;
 
   /**
    * List procedures
    * @return procedure list
    * @throws IOException
    */
   ProcedureInfo[] listProcedures() throws IOException;
 
   /**
    * Abort a procedure but does not block and wait for it be completely removed.
    * You can use Future.get(long, TimeUnit) to wait on the operation to complete.
    * It may throw ExecutionException if there was an error while executing the operation
    * or TimeoutException in case the wait timeout was not long enough to allow the
    * operation to complete.
    *
    * @param procId ID of the procedure to abort
    * @param mayInterruptIfRunning if the proc completed at least one step, should it be aborted?
    * @return true if aborted, false if procedure already completed or does not exist
    * @throws IOException
    */
   Future<Boolean> abortProcedureAsync(
     final long procId,
     final boolean mayInterruptIfRunning) throws IOException;
 
   /**
    * Roll the log writer. I.e. for filesystem based write ahead logs, start writing to a new file.
    *
    * Note that the actual rolling of the log writer is asynchronous and may not be complete when
    * this method returns. As a side effect of this call, the named region server may schedule
    * store flushes at the request of the wal.
    *
    * @param serverName The servername of the regionserver.
    * @throws IOException if a remote or network exception occurs
    * @throws org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException
    */
   void rollWALWriter(ServerName serverName) throws IOException, FailedLogCloseException;
 
   /**
    * Helper delegage to getClusterStatus().getMasterCoprocessors().
    * @return an array of master coprocessors
    * @see org.apache.hadoop.hbase.ClusterStatus#getMasterCoprocessors()
    */
   String[] getMasterCoprocessors() throws IOException;
 
   /**
    * Get the current compaction state of a table. It could be in a major compaction, a minor
    * compaction, both, or none.
    *
    * @param tableName table to examine
    * @return the current compaction state
    * @throws IOException if a remote or network exception occurs
    */
   AdminProtos.GetRegionInfoResponse.CompactionState getCompactionState(final TableName tableName)
     throws IOException;
 
   /**
    * Get the current compaction state of region. It could be in a major compaction, a minor
    * compaction, both, or none.
    *
    * @param regionName region to examine
    * @return the current compaction state
    * @throws IOException if a remote or network exception occurs
    */
   AdminProtos.GetRegionInfoResponse.CompactionState getCompactionStateForRegion(
     final byte[] regionName) throws IOException;
 
   /**
    * Get the timestamp of the last major compaction for the passed table
    *
    * The timestamp of the oldest HFile resulting from a major compaction of that table,
    * or 0 if no such HFile could be found.
    *
    * @param tableName table to examine
    * @return the last major compaction timestamp or 0
    * @throws IOException if a remote or network exception occurs
    */
   long getLastMajorCompactionTimestamp(final TableName tableName)
     throws IOException;
 
   /**
    * Get the timestamp of the last major compaction for the passed region.
    *
    * The timestamp of the oldest HFile resulting from a major compaction of that region,
    * or 0 if no such HFile could be found.
    *
    * @param regionName region to examine
    * @return the last major compaction timestamp or 0
    * @throws IOException if a remote or network exception occurs
    */
   long getLastMajorCompactionTimestampForRegion(final byte[] regionName)
       throws IOException;
 
   /**
    * Take a snapshot for the given table. If the table is enabled, a FLUSH-type snapshot will be
    * taken. If the table is disabled, an offline snapshot is taken. Snapshots are considered unique
    * based on <b>the name of the snapshot</b>. Attempts to take a snapshot with the same name (even
    * a different type or with different parameters) will fail with a {@link
    * org.apache.hadoop.hbase.snapshot.SnapshotCreationException} indicating the duplicate naming.
    * Snapshot names follow the same naming constraints as tables in HBase. See {@link
    * org.apache.hadoop.hbase.TableName#isLegalFullyQualifiedTableName(byte[])}.
    *
    * @param snapshotName name of the snapshot to be created
    * @param tableName name of the table for which snapshot is created
    * @throws IOException if a remote or network exception occurs
    * @throws org.apache.hadoop.hbase.snapshot.SnapshotCreationException if snapshot creation failed
    * @throws IllegalArgumentException if the snapshot request is formatted incorrectly
    */
   void snapshot(final String snapshotName, final TableName tableName)
       throws IOException, SnapshotCreationException, IllegalArgumentException;
 
   /**
    * public void snapshot(final String snapshotName, Create a timestamp consistent snapshot for the
    * given table. final byte[] tableName) throws IOException, Snapshots are considered unique based
    * on <b>the name of the snapshot</b>. Attempts to take a snapshot with the same name (even a
    * different type or with different parameters) will fail with a {@link SnapshotCreationException}
    * indicating the duplicate naming. Snapshot names follow the same naming constraints as tables in
    * HBase.
    *
    * @param snapshotName name of the snapshot to be created
    * @param tableName name of the table for which snapshot is created
    * @throws IOException if a remote or network exception occurs
    * @throws SnapshotCreationException if snapshot creation failed
    * @throws IllegalArgumentException if the snapshot request is formatted incorrectly
    */
   void snapshot(final byte[] snapshotName, final TableName tableName)
       throws IOException, SnapshotCreationException, IllegalArgumentException;
 
   /**
    * Create typed snapshot of the table. Snapshots are considered unique based on <b>the name of the
    * snapshot</b>. Attempts to take a snapshot with the same name (even a different type or with
    * different parameters) will fail with a {@link SnapshotCreationException} indicating the
    * duplicate naming. Snapshot names follow the same naming constraints as tables in HBase. See
    * {@link org.apache.hadoop.hbase.TableName#isLegalFullyQualifiedTableName(byte[])}.
    *
    * @param snapshotName name to give the snapshot on the filesystem. Must be unique from all other
    * snapshots stored on the cluster
    * @param tableName name of the table to snapshot
    * @param type type of snapshot to take
    * @throws IOException we fail to reach the master
    * @throws SnapshotCreationException if snapshot creation failed
    * @throws IllegalArgumentException if the snapshot request is formatted incorrectly
    */
   void snapshot(final String snapshotName,
       final TableName tableName,
       HBaseProtos.SnapshotDescription.Type type) throws IOException, SnapshotCreationException,
       IllegalArgumentException;
 
   /**
    * Take a snapshot and wait for the server to complete that snapshot (blocking). Only a single
    * snapshot should be taken at a time for an instance of HBase, or results may be undefined (you
    * can tell multiple HBase clusters to snapshot at the same time, but only one at a time for a
    * single cluster). Snapshots are considered unique based on <b>the name of the snapshot</b>.
    * Attempts to take a snapshot with the same name (even a different type or with different
    * parameters) will fail with a {@link SnapshotCreationException} indicating the duplicate naming.
    * Snapshot names follow the same naming constraints as tables in HBase. See {@link
    * org.apache.hadoop.hbase.TableName#isLegalFullyQualifiedTableName(byte[])}. You should probably
    * use {@link #snapshot(String, org.apache.hadoop.hbase.TableName)} or
    * {@link #snapshot(byte[], org.apache.hadoop.hbase.TableName)} unless you are sure about the type
    * of snapshot that you want to take.
    *
    * @param snapshot snapshot to take
    * @throws IOException or we lose contact with the master.
    * @throws SnapshotCreationException if snapshot failed to be taken
    * @throws IllegalArgumentException if the snapshot request is formatted incorrectly
    */
   void snapshot(HBaseProtos.SnapshotDescription snapshot)
       throws IOException, SnapshotCreationException, IllegalArgumentException;
 
   /**
    * Take a snapshot without waiting for the server to complete that snapshot (asynchronous) Only a
    * single snapshot should be taken at a time, or results may be undefined.
    *
    * @param snapshot snapshot to take
    * @return response from the server indicating the max time to wait for the snapshot
    * @throws IOException if the snapshot did not succeed or we lose contact with the master.
    * @throws SnapshotCreationException if snapshot creation failed
    * @throws IllegalArgumentException if the snapshot request is formatted incorrectly
    */
   MasterProtos.SnapshotResponse takeSnapshotAsync(HBaseProtos.SnapshotDescription snapshot)
       throws IOException, SnapshotCreationException;
 
   /**
    * Check the current state of the passed snapshot. There are three possible states: <ol>
    * <li>running - returns <tt>false</tt></li> <li>finished - returns <tt>true</tt></li>
    * <li>finished with error - throws the exception that caused the snapshot to fail</li> </ol> The
    * cluster only knows about the most recent snapshot. Therefore, if another snapshot has been
    * run/started since the snapshot your are checking, you will recieve an {@link
    * org.apache.hadoop.hbase.snapshot.UnknownSnapshotException}.
    *
    * @param snapshot description of the snapshot to check
    * @return <tt>true</tt> if the snapshot is completed, <tt>false</tt> if the snapshot is still
    * running
    * @throws IOException if we have a network issue
    * @throws org.apache.hadoop.hbase.snapshot.HBaseSnapshotException if the snapshot failed
    * @throws org.apache.hadoop.hbase.snapshot.UnknownSnapshotException if the requested snapshot is
    * unknown
    */
   boolean isSnapshotFinished(final HBaseProtos.SnapshotDescription snapshot)
       throws IOException, HBaseSnapshotException, UnknownSnapshotException;
 
   /**
    * Restore the specified snapshot on the original table. (The table must be disabled) If the
    * "hbase.snapshot.restore.take.failsafe.snapshot" configuration property is set to true, a
    * snapshot of the current table is taken before executing the restore operation. In case of
    * restore failure, the failsafe snapshot will be restored. If the restore completes without
    * problem the failsafe snapshot is deleted.
    *
    * @param snapshotName name of the snapshot to restore
    * @throws IOException if a remote or network exception occurs
    * @throws org.apache.hadoop.hbase.snapshot.RestoreSnapshotException if snapshot failed to be
    * restored
    * @throws IllegalArgumentException if the restore request is formatted incorrectly
    */
   void restoreSnapshot(final byte[] snapshotName) throws IOException, RestoreSnapshotException;
 
   /**
    * Restore the specified snapshot on the original table. (The table must be disabled) If the
    * "hbase.snapshot.restore.take.failsafe.snapshot" configuration property is set to true, a
    * snapshot of the current table is taken before executing the restore operation. In case of
    * restore failure, the failsafe snapshot will be restored. If the restore completes without
    * problem the failsafe snapshot is deleted.
    *
    * @param snapshotName name of the snapshot to restore
    * @throws IOException if a remote or network exception occurs
    * @throws RestoreSnapshotException if snapshot failed to be restored
    * @throws IllegalArgumentException if the restore request is formatted incorrectly
    */
   void restoreSnapshot(final String snapshotName) throws IOException, RestoreSnapshotException;
 
   /**
    * Restore the specified snapshot on the original table. (The table must be disabled) If
    * 'takeFailSafeSnapshot' is set to true, a snapshot of the current table is taken before
    * executing the restore operation. In case of restore failure, the failsafe snapshot will be
    * restored. If the restore completes without problem the failsafe snapshot is deleted. The
    * failsafe snapshot name is configurable by using the property
    * "hbase.snapshot.restore.failsafe.name".
    *
    * @param snapshotName name of the snapshot to restore
    * @param takeFailSafeSnapshot true if the failsafe snapshot should be taken
    * @throws IOException if a remote or network exception occurs
    * @throws RestoreSnapshotException if snapshot failed to be restored
    * @throws IllegalArgumentException if the restore request is formatted incorrectly
    */
   void restoreSnapshot(final byte[] snapshotName, final boolean takeFailSafeSnapshot)
       throws IOException, RestoreSnapshotException;
 
   /**
    * Restore the specified snapshot on the original table. (The table must be disabled) If
    * 'takeFailSafeSnapshot' is set to true, a snapshot of the current table is taken before
    * executing the restore operation. In case of restore failure, the failsafe snapshot will be
    * restored. If the restore completes without problem the failsafe snapshot is deleted. The
    * failsafe snapshot name is configurable by using the property
    * "hbase.snapshot.restore.failsafe.name".
    *
    * @param snapshotName name of the snapshot to restore
    * @param takeFailSafeSnapshot true if the failsafe snapshot should be taken
    * @throws IOException if a remote or network exception occurs
    * @throws RestoreSnapshotException if snapshot failed to be restored
    * @throws IllegalArgumentException if the restore request is formatted incorrectly
    */
   void restoreSnapshot(final String snapshotName, boolean takeFailSafeSnapshot)
       throws IOException, RestoreSnapshotException;
 
   /**
    * Create a new table by cloning the snapshot content.
    *
    * @param snapshotName name of the snapshot to be cloned
    * @param tableName name of the table where the snapshot will be restored
    * @throws IOException if a remote or network exception occurs
    * @throws TableExistsException if table to be created already exists
    * @throws RestoreSnapshotException if snapshot failed to be cloned
    * @throws IllegalArgumentException if the specified table has not a valid name
    */
   void cloneSnapshot(final byte[] snapshotName, final TableName tableName)
       throws IOException, TableExistsException, RestoreSnapshotException;
 
   /**
    * Create a new table by cloning the snapshot content.
    *
    * @param snapshotName name of the snapshot to be cloned
    * @param tableName name of the table where the snapshot will be restored
    * @throws IOException if a remote or network exception occurs
    * @throws TableExistsException if table to be created already exists
    * @throws RestoreSnapshotException if snapshot failed to be cloned
    * @throws IllegalArgumentException if the specified table has not a valid name
    */
   void cloneSnapshot(final String snapshotName, final TableName tableName)
       throws IOException, TableExistsException, RestoreSnapshotException;
 
   /**
    * Execute a distributed procedure on a cluster.
    *
    * @param signature A distributed procedure is uniquely identified by its signature (default the
    * root ZK node name of the procedure).
    * @param instance The instance name of the procedure. For some procedures, this parameter is
    * optional.
    * @param props Property/Value pairs of properties passing to the procedure
    * @throws IOException
    */
   void execProcedure(String signature, String instance, Map<String, String> props)
       throws IOException;
 
   /**
    * Execute a distributed procedure on a cluster.
    *
    * @param signature A distributed procedure is uniquely identified by its signature (default the
    * root ZK node name of the procedure).
    * @param instance The instance name of the procedure. For some procedures, this parameter is
    * optional.
    * @param props Property/Value pairs of properties passing to the procedure
    * @return data returned after procedure execution. null if no return data.
    * @throws IOException
    */
   byte[] execProcedureWithRet(String signature, String instance, Map<String, String> props)
       throws IOException;
 
   /**
    * Check the current state of the specified procedure. There are three possible states: <ol>
    * <li>running - returns <tt>false</tt></li> <li>finished - returns <tt>true</tt></li>
    * <li>finished with error - throws the exception that caused the procedure to fail</li> </ol>
    *
    * @param signature The signature that uniquely identifies a procedure
    * @param instance The instance name of the procedure
    * @param props Property/Value pairs of properties passing to the procedure
    * @return true if the specified procedure is finished successfully, false if it is still running
    * @throws IOException if the specified procedure finished with error
    */
   boolean isProcedureFinished(String signature, String instance, Map<String, String> props)
       throws IOException;
 
   /**
    * List completed snapshots.
    *
    * @return a list of snapshot descriptors for completed snapshots
    * @throws IOException if a network error occurs
    */
   List<HBaseProtos.SnapshotDescription> listSnapshots() throws IOException;
 
   /**
    * List all the completed snapshots matching the given regular expression.
    *
    * @param regex The regular expression to match against
    * @return - returns a List of SnapshotDescription
    * @throws IOException if a remote or network exception occurs
    */
   List<HBaseProtos.SnapshotDescription> listSnapshots(String regex) throws IOException;
 
   /**
    * List all the completed snapshots matching the given pattern.
    *
    * @param pattern The compiled regular expression to match against
    * @return - returns a List of SnapshotDescription
    * @throws IOException if a remote or network exception occurs
    */
   List<HBaseProtos.SnapshotDescription> listSnapshots(Pattern pattern) throws IOException;
 
   /**
    * Delete an existing snapshot.
    *
    * @param snapshotName name of the snapshot
    * @throws IOException if a remote or network exception occurs
    */
   void deleteSnapshot(final byte[] snapshotName) throws IOException;
 
   /**
    * Delete an existing snapshot.
    *
    * @param snapshotName name of the snapshot
    * @throws IOException if a remote or network exception occurs
    */
   void deleteSnapshot(final String snapshotName) throws IOException;
 
   /**
    * Delete existing snapshots whose names match the pattern passed.
    *
    * @param regex The regular expression to match against
    * @throws IOException if a remote or network exception occurs
    */
   void deleteSnapshots(final String regex) throws IOException;
 
   /**
    * Delete existing snapshots whose names match the pattern passed.
    *
    * @param pattern pattern for names of the snapshot to match
    * @throws IOException if a remote or network exception occurs
    */
   void deleteSnapshots(final Pattern pattern) throws IOException;
   
   /**
    * Apply the new quota settings.
    * @param quota the quota settings
    * @throws IOException if a remote or network exception occurs
    */
   void setQuota(final QuotaSettings quota) throws IOException;
 
   /**
    * Return a QuotaRetriever to list the quotas based on the filter.
    * @param filter the quota settings filter
    * @return the quota retriever
    * @throws IOException if a remote or network exception occurs
    */
   QuotaRetriever getQuotaRetriever(final QuotaFilter filter) throws IOException;
 
   /**
    * Creates and returns a {@link com.google.protobuf.RpcChannel} instance connected to the active
    * master. <p> The obtained {@link com.google.protobuf.RpcChannel} instance can be used to access
    * a published coprocessor {@link com.google.protobuf.Service} using standard protobuf service
    * invocations: </p> <div style="background-color: #cccccc; padding: 2px">
    * <blockquote><pre>
    * CoprocessorRpcChannel channel = myAdmin.coprocessorService();
    * MyService.BlockingInterface service = MyService.newBlockingStub(channel);
    * MyCallRequest request = MyCallRequest.newBuilder()
    *     ...
    *     .build();
    * MyCallResponse response = service.myCall(null, request);
    * </pre></blockquote></div>
    *
    * @return A MasterCoprocessorRpcChannel instance
    */
   CoprocessorRpcChannel coprocessorService();
 
 
   /**
    * Creates and returns a {@link com.google.protobuf.RpcChannel} instance
    * connected to the passed region server.
    *
    * <p>
    * The obtained {@link com.google.protobuf.RpcChannel} instance can be used to access a published
    * coprocessor {@link com.google.protobuf.Service} using standard protobuf service invocations:
    * </p>
    *
    * <div style="background-color: #cccccc; padding: 2px">
    * <blockquote><pre>
    * CoprocessorRpcChannel channel = myAdmin.coprocessorService(serverName);
    * MyService.BlockingInterface service = MyService.newBlockingStub(channel);
    * MyCallRequest request = MyCallRequest.newBuilder()
    *     ...
    *     .build();
    * MyCallResponse response = service.myCall(null, request);
    * </pre></blockquote></div>
    *
    * @param sn the server name to which the endpoint call is made
    * @return A RegionServerCoprocessorRpcChannel instance
    */
   CoprocessorRpcChannel coprocessorService(ServerName sn);
 
 
   /**
    * Update the configuration and trigger an online config change
    * on the regionserver
    * @param server : The server whose config needs to be updated.
    * @throws IOException
    */
   void updateConfiguration(ServerName server) throws IOException;
 
 
   /**
    * Update the configuration and trigger an online config change
    * on all the regionservers
    * @throws IOException
    */
   void updateConfiguration() throws IOException;
 
   /**
    * Get the info port of the current master if one is available.
    * @return master info port
    * @throws IOException
    */
   public int getMasterInfoPort() throws IOException;
 }