/**
* 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.replication;
import java.io.IOException;
import java.util.List;
import java.util.UUID;
import org.apache.hadoop.hbase.Abortable;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.TableDescriptors;
import org.apache.hadoop.hbase.wal.WAL.Entry;
import org.apache.hadoop.hbase.replication.regionserver.MetricsSource;
import com.google.common.util.concurrent.Service;
/**
* ReplicationEndpoint is a plugin which implements replication
* to other HBase clusters, or other systems. ReplicationEndpoint implementation
* can be specified at the peer creation time by specifying it
* in the {@link ReplicationPeerConfig}. A ReplicationEndpoint is run in a thread
* in each region server in the same process.
* <p>
* ReplicationEndpoint is closely tied to ReplicationSource in a producer-consumer
* relation. ReplicationSource is an HBase-private class which tails the logs and manages
* the queue of logs plus management and persistence of all the state for replication.
* ReplicationEndpoint on the other hand is responsible for doing the actual shipping
* and persisting of the WAL entries in the other cluster.
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)
public interface ReplicationEndpoint extends Service, ReplicationPeerConfigListener {
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)
class Context {
private final Configuration conf;
private final FileSystem fs;
private final TableDescriptors tableDescriptors;
private final ReplicationPeer replicationPeer;
private final String peerId;
private final UUID clusterId;
private final MetricsSource metrics;
private final Abortable abortable;
@InterfaceAudience.Private
public Context(
final Configuration conf,
final FileSystem fs,
final String peerId,
final UUID clusterId,
final ReplicationPeer replicationPeer,
final MetricsSource metrics,
final TableDescriptors tableDescriptors,
final Abortable abortable) {
this.conf = conf;
this.fs = fs;
this.clusterId = clusterId;
this.peerId = peerId;
this.replicationPeer = replicationPeer;
this.metrics = metrics;
this.tableDescriptors = tableDescriptors;
this.abortable = abortable;
}
public Configuration getConfiguration() {
return conf;
}
public FileSystem getFilesystem() {
return fs;
}
public UUID getClusterId() {
return clusterId;
}
public String getPeerId() {
return peerId;
}
public ReplicationPeerConfig getPeerConfig() {
return replicationPeer.getPeerConfig();
}
public ReplicationPeer getReplicationPeer() {
return replicationPeer;
}
public MetricsSource getMetrics() {
return metrics;
}
public TableDescriptors getTableDescriptors() {
return tableDescriptors;
}
public Abortable getAbortable() { return abortable; }
}
/**
* Initialize the replication endpoint with the given context.
* @param context replication context
* @throws IOException
*/
void init(Context context) throws IOException;
/** Whether or not, the replication endpoint can replicate to it's source cluster with the same
* UUID */
boolean canReplicateToSameCluster();
/**
* Returns a UUID of the provided peer id. Every HBase cluster instance has a persisted
* associated UUID. If the replication is not performed to an actual HBase cluster (but
* some other system), the UUID returned has to uniquely identify the connected target system.
* @return a UUID or null if the peer cluster does not exist or is not connected.
*/
UUID getPeerUUID();
/**
* Returns a WALEntryFilter to use for filtering out WALEntries from the log. Replication
* infrastructure will call this filter before sending the edits to shipEdits().
* @return a {@link WALEntryFilter} or null.
*/
WALEntryFilter getWALEntryfilter();
/**
* A context for {@link ReplicationEndpoint#replicate(ReplicateContext)} method.
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)
static class ReplicateContext {
List<Entry> entries;
int size;
String walGroupId;
@InterfaceAudience.Private
public ReplicateContext() {
}
public ReplicateContext setEntries(List<Entry> entries) {
this.entries = entries;
return this;
}
public ReplicateContext setSize(int size) {
this.size = size;
return this;
}
public ReplicateContext setWalGroupId(String walGroupId) {
this.walGroupId = walGroupId;
return this;
}
public List<Entry> getEntries() {
return entries;
}
public int getSize() {
return size;
}
public String getWalGroupId(){
return walGroupId;
}
}
/**
* Replicate the given set of entries (in the context) to the other cluster.
* Can block until all the given entries are replicated. Upon this method is returned,
* all entries that were passed in the context are assumed to be persisted in the
* target cluster.
* @param replicateContext a context where WAL entries and other
* parameters can be obtained.
*/
boolean replicate(ReplicateContext replicateContext);
}