/*
*
* 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.regionserver;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellScanner;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.KeyValueUtil;
import org.apache.hadoop.hbase.Stoppable;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Row;
import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.WALEntry;
import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
/**
* This class is responsible for replicating the edits coming
* from another cluster.
* <p/>
* This replication process is currently waiting for the edits to be applied
* before the method can return. This means that the replication of edits
* is synchronized (after reading from HLogs in ReplicationSource) and that a
* single region server cannot receive edits from two sources at the same time
* <p/>
* This class uses the native HBase client in order to replicate entries.
* <p/>
*
* TODO make this class more like ReplicationSource wrt log handling
*/
@InterfaceAudience.Private
public class ReplicationSink {
private static final Log LOG = LogFactory.getLog(ReplicationSink.class);
private final Configuration conf;
private final HConnection sharedHtableCon;
private final MetricsSink metrics;
private final AtomicLong totalReplicatedEdits = new AtomicLong();
/**
* Create a sink for replication
*
* @param conf conf object
* @param stopper boolean to tell this thread to stop
* @throws IOException thrown when HDFS goes bad or bad file name
*/
public ReplicationSink(Configuration conf, Stoppable stopper)
throws IOException {
this.conf = HBaseConfiguration.create(conf);
decorateConf();
this.metrics = new MetricsSink();
this.sharedHtableCon = HConnectionManager.createConnection(this.conf);
}
/**
* decorate the Configuration object to make replication more receptive to delays:
* lessen the timeout and numTries.
*/
private void decorateConf() {
this.conf.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER,
this.conf.getInt("replication.sink.client.retries.number", 4));
this.conf.setInt(HConstants.HBASE_CLIENT_OPERATION_TIMEOUT,
this.conf.getInt("replication.sink.client.ops.timeout", 10000));
String replicationCodec = this.conf.get(HConstants.REPLICATION_CODEC_CONF_KEY);
if (StringUtils.isNotEmpty(replicationCodec)) {
this.conf.set(HConstants.RPC_CODEC_CONF_KEY, replicationCodec);
}
}
/**
* Replicate this array of entries directly into the local cluster using the native client. Only
* operates against raw protobuf type saving on a conversion from pb to pojo.
* @param entries
* @param cells
* @throws IOException
*/
public void replicateEntries(List<WALEntry> entries, final CellScanner cells) throws IOException {
if (entries.isEmpty()) return;
if (cells == null) throw new NullPointerException("TODO: Add handling of null CellScanner");
// Very simple optimization where we batch sequences of rows going
// to the same table.
try {
long totalReplicated = 0;
// Map of table => list of Rows, grouped by cluster id, we only want to flushCommits once per
// invocation of this method per table and cluster id.
Map<TableName, Map<List<UUID>, List<Row>>> rowMap =
new TreeMap<TableName, Map<List<UUID>, List<Row>>>();
for (WALEntry entry : entries) {
TableName table =
TableName.valueOf(entry.getKey().getTableName().toByteArray());
Cell previousCell = null;
Mutation m = null;
int count = entry.getAssociatedCellCount();
for (int i = 0; i < count; i++) {
// Throw index out of bounds if our cell count is off
if (!cells.advance()) {
throw new ArrayIndexOutOfBoundsException("Expected=" + count + ", index=" + i);
}
Cell cell = cells.current();
if (isNewRowOrType(previousCell, cell)) {
// Create new mutation
m = CellUtil.isDelete(cell)?
new Delete(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength()):
new Put(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength());
List<UUID> clusterIds = new ArrayList<UUID>();
for(HBaseProtos.UUID clusterId : entry.getKey().getClusterIdsList()){
clusterIds.add(toUUID(clusterId));
}
m.setClusterIds(clusterIds);
addToHashMultiMap(rowMap, table, clusterIds, m);
}
if (CellUtil.isDelete(cell)) {
((Delete)m).addDeleteMarker(KeyValueUtil.ensureKeyValue(cell));
} else {
((Put)m).add(KeyValueUtil.ensureKeyValue(cell));
}
previousCell = cell;
}
totalReplicated++;
}
for (Entry<TableName, Map<List<UUID>,List<Row>>> entry : rowMap.entrySet()) {
batch(entry.getKey(), entry.getValue().values());
}
int size = entries.size();
this.metrics.setAgeOfLastAppliedOp(entries.get(size - 1).getKey().getWriteTime());
this.metrics.applyBatch(size);
this.totalReplicatedEdits.addAndGet(totalReplicated);
} catch (IOException ex) {
LOG.error("Unable to accept edit because:", ex);
throw ex;
}
}
/**
* @param previousCell
* @param cell
* @return True if we have crossed over onto a new row or type
*/
private boolean isNewRowOrType(final Cell previousCell, final Cell cell) {
return previousCell == null || previousCell.getTypeByte() != cell.getTypeByte() ||
!CellUtil.matchingRow(previousCell, cell);
}
private java.util.UUID toUUID(final HBaseProtos.UUID uuid) {
return new java.util.UUID(uuid.getMostSigBits(), uuid.getLeastSigBits());
}
/**
* Simple helper to a map from key to (a list of) values
* TODO: Make a general utility method
* @param map
* @param key1
* @param key2
* @param value
* @return the list of values corresponding to key1 and key2
*/
private <K1, K2, V> List<V> addToHashMultiMap(Map<K1, Map<K2,List<V>>> map, K1 key1, K2 key2, V value) {
Map<K2,List<V>> innerMap = map.get(key1);
if (innerMap == null) {
innerMap = new HashMap<K2, List<V>>();
map.put(key1, innerMap);
}
List<V> values = innerMap.get(key2);
if (values == null) {
values = new ArrayList<V>();
innerMap.put(key2, values);
}
values.add(value);
return values;
}
/**
* stop the thread pool executor. It is called when the regionserver is stopped.
*/
public void stopReplicationSinkServices() {
try {
this.sharedHtableCon.close();
} catch (IOException e) {
LOG.warn("IOException while closing the connection", e); // ignoring as we are closing.
}
}
/**
* Do the changes and handle the pool
* @param tableName table to insert into
* @param allRows list of actions
* @throws IOException
*/
protected void batch(TableName tableName, Collection<List<Row>> allRows) throws IOException {
if (allRows.isEmpty()) {
return;
}
HTableInterface table = null;
try {
table = this.sharedHtableCon.getTable(tableName);
for (List<Row> rows : allRows) {
table.batch(rows);
}
} catch (InterruptedException ix) {
throw (InterruptedIOException)new InterruptedIOException().initCause(ix);
} finally {
if (table != null) {
table.close();
}
}
}
/**
* Get a string representation of this sink's metrics
* @return string with the total replicated edits count and the date
* of the last edit that was applied
*/
public String getStats() {
return this.totalReplicatedEdits.get() == 0 ? "" : "Sink: " +
"age in ms of last applied edit: " + this.metrics.refreshAgeOfLastAppliedOp() +
", total replicated edits: " + this.totalReplicatedEdits;
}
}