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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;
import java.io.IOException;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.exceptions.DeserializationException;
import org.apache.hadoop.hbase.MetaTableAccessor.Visitor;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.util.Bytes;
/**
* A tool to migrate the data stored in hbase:meta table to pbuf serialization.
* Supports migrating from 0.92.x and 0.94.x to 0.96.x for the catalog table.
* @deprecated will be removed for the major release after 0.96.
*/
@Deprecated
public class MetaMigrationConvertingToPB {
private static final Log LOG = LogFactory.getLog(MetaMigrationConvertingToPB.class);
private static class ConvertToPBMetaVisitor implements Visitor {
private final MasterServices services;
private long numMigratedRows;
public ConvertToPBMetaVisitor(MasterServices services) {
this.services = services;
numMigratedRows = 0;
}
@Override
public boolean visit(Result r) throws IOException {
if (r == null || r.isEmpty()) return true;
// Check info:regioninfo, info:splitA, and info:splitB. Make sure all
// have migrated HRegionInfos.
byte [] hriBytes = getBytes(r, HConstants.REGIONINFO_QUALIFIER);
// Presumes that an edit updating all three cells either succeeds or
// doesn't -- that we don't have case of info:regioninfo migrated but not
// info:splitA.
if (isMigrated(hriBytes)) return true;
// OK. Need to migrate this row in meta.
//This will 'migrate' the HRI from 092.x and 0.94.x to 0.96+ by reading the
//writable serialization
HRegionInfo hri = parseFrom(hriBytes);
// Now make a put to write back to meta.
Put p = MetaTableAccessor.makePutFromRegionInfo(hri);
// Now migrate info:splitA and info:splitB if they are not null
migrateSplitIfNecessary(r, p, HConstants.SPLITA_QUALIFIER);
migrateSplitIfNecessary(r, p, HConstants.SPLITB_QUALIFIER);
MetaTableAccessor.putToMetaTable(this.services.getConnection(), p);
if (LOG.isDebugEnabled()) {
LOG.debug("Migrated " + Bytes.toString(p.getRow()));
}
numMigratedRows++;
return true;
}
}
static void migrateSplitIfNecessary(final Result r, final Put p, final byte [] which)
throws IOException {
byte [] hriSplitBytes = getBytes(r, which);
if (!isMigrated(hriSplitBytes)) {
//This will 'migrate' the HRI from 092.x and 0.94.x to 0.96+ by reading the
//writable serialization
HRegionInfo hri = parseFrom(hriSplitBytes);
p.addImmutable(HConstants.CATALOG_FAMILY, which, hri.toByteArray());
}
}
static HRegionInfo parseFrom(byte[] hriBytes) throws IOException {
try {
return HRegionInfo.parseFrom(hriBytes);
} catch (DeserializationException ex) {
throw new IOException(ex);
}
}
/**
* @param r Result to dig in.
* @param qualifier Qualifier to look at in the passed r.
* @return Bytes for an HRegionInfo or null if no bytes or empty bytes found.
*/
static byte [] getBytes(final Result r, final byte [] qualifier) {
byte [] hriBytes = r.getValue(HConstants.CATALOG_FAMILY, qualifier);
if (hriBytes == null || hriBytes.length <= 0) return null;
return hriBytes;
}
static boolean isMigrated(final byte [] hriBytes) {
if (hriBytes == null || hriBytes.length <= 0) return true;
return ProtobufUtil.isPBMagicPrefix(hriBytes);
}
/**
* Converting writable serialization to PB, if it is needed.
* @param services MasterServices to get a handle on master
* @return num migrated rows
* @throws IOException or RuntimeException if something goes wrong
*/
public static long updateMetaIfNecessary(final MasterServices services)
throws IOException {
if (isMetaTableUpdated(services.getConnection())) {
LOG.info("META already up-to date with PB serialization");
return 0;
}
LOG.info("META has Writable serializations, migrating hbase:meta to PB serialization");
try {
long rows = updateMeta(services);
LOG.info("META updated with PB serialization. Total rows updated: " + rows);
return rows;
} catch (IOException e) {
LOG.warn("Update hbase:meta with PB serialization failed." + "Master startup aborted.");
throw e;
}
}
/**
* Update hbase:meta rows, converting writable serialization to PB
* @return num migrated rows
*/
static long updateMeta(final MasterServices masterServices) throws IOException {
LOG.info("Starting update of META");
ConvertToPBMetaVisitor v = new ConvertToPBMetaVisitor(masterServices);
MetaTableAccessor.fullScan(masterServices.getConnection(), v);
LOG.info("Finished update of META. Total rows updated:" + v.numMigratedRows);
return v.numMigratedRows;
}
/**
* @param hConnection connection to be used
* @return True if the meta table has been migrated.
* @throws IOException
*/
static boolean isMetaTableUpdated(final HConnection hConnection) throws IOException {
List results = MetaTableAccessor.fullScanOfMeta(hConnection);
if (results == null || results.isEmpty()) {
LOG.info("hbase:meta doesn't have any entries to update.");
return true;
}
for (Result r : results) {
byte[] value = r.getValue(HConstants.CATALOG_FAMILY, HConstants.REGIONINFO_QUALIFIER);
if (!isMigrated(value)) {
return false;
}
}
return true;
}
}