org.apache.hudi.org.apache.hadoop.hbase.client.Connection Maven / Gradle / Ivy
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* 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.concurrent.ExecutorService;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Abortable;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.yetus.audience.InterfaceAudience;
/**
* A cluster connection encapsulating lower level individual connections to actual servers and
* a connection to zookeeper. Connections are instantiated through the {@link ConnectionFactory}
* class. The lifecycle of the connection is managed by the caller, who has to {@link #close()}
* the connection to release the resources.
*
* The connection object contains logic to find the master, locate regions out on the cluster,
* keeps a cache of locations and then knows how to re-calibrate after they move. The individual
* connections to servers, meta cache, zookeeper connection, etc are all shared by the
* {@link Table} and {@link Admin} instances obtained from this connection.
*
*
Connection creation is a heavy-weight operation. Connection implementations are thread-safe,
* so that the client can create a connection once, and share it with different threads.
* {@link Table} and {@link Admin} instances, on the other hand, are light-weight and are not
* thread-safe. Typically, a single connection per client application is instantiated and every
* thread will obtain its own Table instance. Caching or pooling of {@link Table} and {@link Admin}
* is not recommended.
*
* @see ConnectionFactory
* @since 0.99.0
*/
@InterfaceAudience.Public
public interface Connection extends Abortable, Closeable {
/*
* Implementation notes:
* - Only allow new style of interfaces:
* -- All table names are passed as TableName. No more byte[] and string arguments
* -- Most of the classes with names H is deprecated in favor of non-H versions
* (Table, Connection, etc)
* -- Only real client-facing public methods are allowed
* - Connection should contain only getTable(), getAdmin() kind of general methods.
*/
/**
* @return Configuration instance being used by this Connection instance.
*/
Configuration getConfiguration();
/**
* Retrieve a Table implementation for accessing a table.
* The returned Table is not thread safe, a new instance should be created for each using thread.
* This is a lightweight operation, pooling or caching of the returned Table
* is neither required nor desired.
*
* The caller is responsible for calling {@link Table#close()} on the returned
* table instance.
*
* Since 0.98.1 this method no longer checks table existence. An exception
* will be thrown if the table does not exist only when the first operation is
* attempted.
* @param tableName the name of the table
* @return a Table to use for interactions with this table
*/
default Table getTable(TableName tableName) throws IOException {
return getTable(tableName, null);
}
/**
* Retrieve a Table implementation for accessing a table.
* The returned Table is not thread safe, a new instance should be created for each using thread.
* This is a lightweight operation, pooling or caching of the returned Table
* is neither required nor desired.
*
* The caller is responsible for calling {@link Table#close()} on the returned
* table instance.
*
* Since 0.98.1 this method no longer checks table existence. An exception
* will be thrown if the table does not exist only when the first operation is
* attempted.
*
* @param tableName the name of the table
* @param pool The thread pool to use for batch operations, null to use a default pool.
* @return a Table to use for interactions with this table
*/
default Table getTable(TableName tableName, ExecutorService pool) throws IOException {
return getTableBuilder(tableName, pool).build();
}
/**
*
* Retrieve a {@link BufferedMutator} for performing client-side buffering of writes. The
* {@link BufferedMutator} returned by this method is thread-safe.
* This accessor will create a new ThreadPoolExecutor and will be shutdown once we close the
* BufferedMutator. This object can be used for long lived operations.
*
*
* The caller is responsible for calling {@link BufferedMutator#close()} on
* the returned {@link BufferedMutator} instance.
*
*
*
* @param tableName the name of the table
*
* @return a {@link BufferedMutator} for the supplied tableName.
*/
BufferedMutator getBufferedMutator(TableName tableName) throws IOException;
/**
* Retrieve a {@link BufferedMutator} for performing client-side buffering of writes. The
* {@link BufferedMutator} returned by this method is thread-safe. This object can be used for
* long lived table operations. If user passes ThreadPool in BufferedMutatorParams then we will
* use that otherwise we will create for the user. For user specified ThreadPool, it is the user's
* responsibility to shutdown. For ThreadPool created by us, we will shutdown when user calls
* {@link BufferedMutator#close()}. The caller is responsible for calling
* {@link BufferedMutator#close()} on the returned {@link BufferedMutator} instance.
*
* @param params details on how to instantiate the {@code BufferedMutator}.
* @return a {@link BufferedMutator} for the supplied tableName.
*/
BufferedMutator getBufferedMutator(BufferedMutatorParams params) throws IOException;
/**
* Retrieve a RegionLocator implementation to inspect region information on a table. The returned
* RegionLocator is not thread-safe, so a new instance should be created for each using thread.
*
* This is a lightweight operation. Pooling or caching of the returned RegionLocator is neither
* required nor desired.
*
* The caller is responsible for calling {@link RegionLocator#close()} on the returned
* RegionLocator instance.
*
* RegionLocator needs to be unmanaged
*
* @param tableName Name of the table who's region is to be examined
* @return A RegionLocator instance
*/
RegionLocator getRegionLocator(TableName tableName) throws IOException;
/**
* Clear all the entries in the region location cache, for all the tables.
*
* If you only want to clear the cache for a specific table, use
* {@link RegionLocator#clearRegionLocationCache()}.
*
* This may cause performance issue so use it with caution.
*/
void clearRegionLocationCache();
/**
* Retrieve an Admin implementation to administer an HBase cluster.
* The returned Admin is not guaranteed to be thread-safe. A new instance should be created for
* each using thread. This is a lightweight operation. Pooling or caching of the returned
* Admin is not recommended.
*
* The caller is responsible for calling {@link Admin#close()} on the returned
* Admin instance.
*
* @return an Admin instance for cluster administration
*/
Admin getAdmin() throws IOException;
@Override
void close() throws IOException;
/**
* Returns whether the connection is closed or not.
* @return true if this connection is closed
*/
boolean isClosed();
/**
* Returns an {@link TableBuilder} for creating {@link Table}.
* @param tableName the name of the table
* @param pool the thread pool to use for requests like batch and scan
*/
TableBuilder getTableBuilder(TableName tableName, ExecutorService pool);
/**
* Retrieve an Hbck implementation to fix an HBase cluster.
* The returned Hbck is not guaranteed to be thread-safe. A new instance should be created by
* each thread. This is a lightweight operation. Pooling or caching of the returned Hbck instance
* is not recommended.
*
* The caller is responsible for calling {@link Hbck#close()} on the returned Hbck instance.
*
* This will be used mostly by hbck tool.
*
* @return an Hbck instance for active master. Active master is fetched from the zookeeper.
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.HBCK)
default Hbck getHbck() throws IOException {
throw new UnsupportedOperationException("Not implemented");
}
/**
* Retrieve an Hbck implementation to fix an HBase cluster.
* The returned Hbck is not guaranteed to be thread-safe. A new instance should be created by
* each thread. This is a lightweight operation. Pooling or caching of the returned Hbck instance
* is not recommended.
*
* The caller is responsible for calling {@link Hbck#close()} on the returned Hbck instance.
*
* This will be used mostly by hbck tool. This may only be used to by pass getting
* registered master from ZK. In situations where ZK is not available or active master is not
* registered with ZK and user can get master address by other means, master can be explicitly
* specified.
*
* @param masterServer explicit {@link ServerName} for master server
* @return an Hbck instance for a specified master server
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.HBCK)
default Hbck getHbck(ServerName masterServer) throws IOException {
throw new UnsupportedOperationException("Not implemented");
}
}