org.apache.hadoop.hbase.client.CoprocessorHConnection 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.IOException;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.CoprocessorEnvironment;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.client.ConnectionManager.HConnectionImplementation;
import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
import org.apache.hadoop.hbase.regionserver.HRegionServer;
import org.apache.hadoop.hbase.regionserver.RegionServerServices;
import org.apache.hadoop.hbase.security.UserProvider;
/**
* Connection to an HTable from within a Coprocessor. We can do some nice tricks since we know we
* are on a regionserver, for instance skipping the full serialization/deserialization of objects
* when talking to the server.
*
* You should not use this class from any client - its an internal class meant for use by the
* coprocessor framework.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class CoprocessorHConnection extends HConnectionImplementation {
private static final NonceGenerator NO_NONCE_GEN = new ConnectionManager.NoNonceGenerator();
/**
* Create an unmanaged {@link HConnection} based on the environment in which we are running the
* coprocessor. The {@link HConnection} must be externally cleaned up (we bypass the usual HTable
* cleanup mechanisms since we own everything).
* @param env environment hosting the {@link HConnection}
* @return an unmanaged {@link HConnection}.
* @throws IOException if we cannot create the connection
*/
public static ClusterConnection getConnectionForEnvironment(CoprocessorEnvironment env)
throws IOException {
// this bit is a little hacky - just trying to get it going for the moment
if (env instanceof RegionCoprocessorEnvironment) {
RegionCoprocessorEnvironment e = (RegionCoprocessorEnvironment) env;
RegionServerServices services = e.getRegionServerServices();
if (services instanceof HRegionServer) {
return new CoprocessorHConnection((HRegionServer) services);
}
}
return ConnectionManager.createConnectionInternal(env.getConfiguration());
}
private final ServerName serverName;
private final HRegionServer server;
/**
* Legacy constructor
* @param delegate
* @param server
* @throws IOException if we cannot create the connection
* @deprecated delegate is not used
*/
@Deprecated
public CoprocessorHConnection(ClusterConnection delegate, HRegionServer server)
throws IOException {
this(server);
}
/**
* Constructor that uses server configuration
* @param server
* @throws IOException if we cannot create the connection
*/
public CoprocessorHConnection(HRegionServer server) throws IOException {
this(server.getConfiguration(), server);
}
/**
* Constructor that accepts custom configuration
* @param conf
* @param server
* @throws IOException if we cannot create the connection
*/
public CoprocessorHConnection(Configuration conf, HRegionServer server) throws IOException {
super(conf, false, null, UserProvider.instantiate(conf).getCurrent(), server.getClusterId());
this.server = server;
this.serverName = server.getServerName();
}
@Override
public org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ClientService.BlockingInterface
getClient(ServerName serverName) throws IOException {
// client is trying to reach off-server, so we can't do anything special
if (!this.serverName.equals(serverName)) {
return super.getClient(serverName);
}
// the client is attempting to write to the same regionserver, we can short-circuit to our
// local regionserver
return server.getRSRpcServices();
}
@Override
public NonceGenerator getNonceGenerator() {
return NO_NONCE_GEN; // don't use nonces for coprocessor connection
}
}