/** * 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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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 com.google.common.annotations.VisibleForTesting; import com.google.protobuf.ServiceException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.classification.InterfaceAudience; import org.apache.hadoop.hbase.client.ClusterConnection; import org.apache.hadoop.hbase.client.Connection; import org.apache.hadoop.hbase.client.ConnectionFactory; import org.apache.hadoop.hbase.client.Delete; import org.apache.hadoop.hbase.client.Get; import org.apache.hadoop.hbase.client.HTable; import org.apache.hadoop.hbase.client.Mutation; import org.apache.hadoop.hbase.client.Put; import org.apache.hadoop.hbase.client.RegionLocator; import org.apache.hadoop.hbase.client.RegionReplicaUtil; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.client.ResultScanner; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.client.Table; import org.apache.hadoop.hbase.exception.SchemaNotFoundException; import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel; import org.apache.hadoop.hbase.protobuf.ProtobufUtil; import org.apache.hadoop.hbase.protobuf.generated.ClientProtos; import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutationProtos; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.hbase.util.EnvironmentEdgeManager; import org.apache.hadoop.hbase.util.Pair; import org.apache.hadoop.hbase.util.PairOfSameType; import org.apache.hadoop.hbase.util.Threads; import org.apache.hadoop.hbase.zookeeper.MetaTableLocator; import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher; import java.io.IOException; import java.io.InterruptedIOException; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.NavigableMap; import java.util.Set; import java.util.SortedMap; import java.util.TreeMap; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Read/write operations on region and assignment information store in * <code>hbase:meta</code>. * * Some of the methods of this class take ZooKeeperWatcher as a param. The only reason * for this is because when used on client-side (like from HBaseAdmin), we want to use * short-living connection (opened before each operation, closed right after), while * when used on HM or HRS (like in AssignmentManager) we want permanent connection. */ @InterfaceAudience.Private public class MetaTableAccessor { /* * HBASE-10070 adds a replicaId to HRI, meaning more than one HRI can be defined for the * same table range (table, startKey, endKey). For every range, there will be at least one * HRI defined which is called default replica. * * Meta layout (as of 0.98 + HBASE-10070) is like: * For each table range, there is a single row, formatted like: * <tableName>,<startKey>,<regionId>,<encodedRegionName>. This row corresponds to the regionName * of the default region replica. * Columns are: * info:regioninfo => contains serialized HRI for the default region replica * info:server => contains hostname:port (in string form) for the server hosting * the default regionInfo replica * info:server_<replicaId> => contains hostname:port (in string form) for the server hosting the * regionInfo replica with replicaId * info:serverstartcode => contains server start code (in binary long form) for the server * hosting the default regionInfo replica * info:serverstartcode_<replicaId> => contains server start code (in binary long form) for the * server hosting the regionInfo replica with replicaId * info:seqnumDuringOpen => contains seqNum (in binary long form) for the region at the time * the server opened the region with default replicaId * info:seqnumDuringOpen_<replicaId> => contains seqNum (in binary long form) for the region at * the time the server opened the region with replicaId * info:splitA => contains a serialized HRI for the first daughter region if the * region is split * info:splitB => contains a serialized HRI for the second daughter region if the * region is split * info:mergeA => contains a serialized HRI for the first parent region if the * region is the result of a merge * info:mergeB => contains a serialized HRI for the second parent region if the * region is the result of a merge * * The actual layout of meta should be encapsulated inside MetaTableAccessor methods, * and should not leak out of it (through Result objects, etc) */ private static final Log LOG = LogFactory.getLog(MetaTableAccessor.class); static final byte[] META_REGION_PREFIX; static { // Copy the prefix from FIRST_META_REGIONINFO into META_REGION_PREFIX. // FIRST_META_REGIONINFO == 'hbase:meta,,1'. META_REGION_PREFIX == 'hbase:meta,' int len = HRegionInfo.FIRST_META_REGIONINFO.getRegionName().length - 2; META_REGION_PREFIX = new byte[len]; System.arraycopy(HRegionInfo.FIRST_META_REGIONINFO.getRegionName(), 0, META_REGION_PREFIX, 0, len); } /** The delimiter for meta columns for replicaIds > 0 */ protected static final char META_REPLICA_ID_DELIMITER = '_'; /** A regex for parsing server columns from meta. See above javadoc for meta layout */ private static final Pattern SERVER_COLUMN_PATTERN = Pattern.compile("^server(_[0-9a-fA-F]{4})?$"); //////////////////////// // Reading operations // //////////////////////// /** * Performs a full scan of a <code>hbase:meta</code> table. * @return List of {@link org.apache.hadoop.hbase.client.Result} * @throws IOException */ public static List<Result> fullScanOfMeta(Connection connection) throws IOException { CollectAllVisitor v = new CollectAllVisitor(); fullScan(connection, v, null); return v.getResults(); } /** * Performs a full scan of <code>hbase:meta</code>. * @param connection connection we're using * @param visitor Visitor invoked against each row. * @throws IOException */ public static void fullScan(Connection connection, final Visitor visitor) throws IOException { fullScan(connection, visitor, null); } /** * Performs a full scan of <code>hbase:meta</code>. * @param connection connection we're using * @return List of {@link Result} * @throws IOException */ public static List<Result> fullScan(Connection connection) throws IOException { CollectAllVisitor v = new CollectAllVisitor(); fullScan(connection, v, null); return v.getResults(); } /** * Callers should call close on the returned {@link Table} instance. * @param connection connection we're using to access Meta * @return An {@link Table} for <code>hbase:meta</code> * @throws IOException */ static Table getMetaHTable(final Connection connection) throws IOException { // We used to pass whole CatalogTracker in here, now we just pass in Connection if (connection == null || connection.isClosed()) { throw new NullPointerException("No connection"); } // If the passed in 'connection' is 'managed' -- i.e. every second test uses // a Table or an HBaseAdmin with managed connections -- then doing // connection.getTable will throw an exception saying you are NOT to use // managed connections getting tables. Leaving this as it is for now. Will // revisit when inclined to change all tests. User code probaby makes use of // managed connections too so don't change it till post hbase 1.0. // // There should still be a way to use this method with an unmanaged connection. if (connection instanceof ClusterConnection) { if (((ClusterConnection) connection).isManaged()) { return new HTable(TableName.META_TABLE_NAME, (ClusterConnection) connection); } } return connection.getTable(TableName.META_TABLE_NAME); } /** * @param t Table to use (will be closed when done). * @param g Get to run * @throws IOException */ private static Result get(final Table t, final Get g) throws IOException { try { return t.get(g); } finally { t.close(); } } /** * Gets the region info and assignment for the specified region. * @param connection connection we're using * @param regionName Region to lookup. * @return Location and HRegionInfo for <code>regionName</code> * @throws IOException * @deprecated use {@link #getRegionLocation(Connection, byte[])} instead */ @Deprecated public static Pair<HRegionInfo, ServerName> getRegion(Connection connection, byte[] regionName) throws IOException { HRegionLocation location = getRegionLocation(connection, regionName); return location == null ? null : new Pair<HRegionInfo, ServerName>(location.getRegionInfo(), location.getServerName()); } /** * Returns the HRegionLocation from meta for the given region * @param connection connection we're using * @param regionName region we're looking for * @return HRegionLocation for the given region * @throws IOException */ public static HRegionLocation getRegionLocation(Connection connection, byte[] regionName) throws IOException { byte[] row = regionName; HRegionInfo parsedInfo = null; try { parsedInfo = parseRegionInfoFromRegionName(regionName); row = getMetaKeyForRegion(parsedInfo); } catch (Exception parseEx) { // Ignore. This is used with tableName passed as regionName. } Get get = new Get(row); get.addFamily(HConstants.CATALOG_FAMILY); Result r = get(getMetaHTable(connection), get); RegionLocations locations = getRegionLocations(r); return locations == null ? null : locations.getRegionLocation(parsedInfo == null ? 0 : parsedInfo.getReplicaId()); } /** * Returns the HRegionLocation from meta for the given region * @param connection connection we're using * @param regionInfo region information * @return HRegionLocation for the given region * @throws IOException */ public static HRegionLocation getRegionLocation(Connection connection, HRegionInfo regionInfo) throws IOException { byte[] row = getMetaKeyForRegion(regionInfo); Get get = new Get(row); get.addFamily(HConstants.CATALOG_FAMILY); Result r = get(getMetaHTable(connection), get); return getRegionLocation(r, regionInfo, regionInfo.getReplicaId()); } /** Returns the row key to use for this regionInfo */ public static byte[] getMetaKeyForRegion(HRegionInfo regionInfo) { return RegionReplicaUtil.getRegionInfoForDefaultReplica(regionInfo).getRegionName(); } /** Returns an HRI parsed from this regionName. Not all the fields of the HRI * is stored in the name, so the returned object should only be used for the fields * in the regionName. */ protected static HRegionInfo parseRegionInfoFromRegionName(byte[] regionName) throws IOException { byte[][] fields = HRegionInfo.parseRegionName(regionName); long regionId = Long.parseLong(Bytes.toString(fields[2])); int replicaId = fields.length > 3 ? Integer.parseInt(Bytes.toString(fields[3]), 16) : 0; return new HRegionInfo( TableName.valueOf(fields[0]), fields[1], fields[1], false, regionId, replicaId); } /** * Gets the result in hbase:meta for the specified region. * @param connection connection we're using * @param regionName region we're looking for * @return result of the specified region * @throws IOException */ public static Result getRegionResult(Connection connection, byte[] regionName) throws IOException { Get get = new Get(regionName); get.addFamily(HConstants.CATALOG_FAMILY); return get(getMetaHTable(connection), get); } /** * Get regions from the merge qualifier of the specified merged region * @return null if it doesn't contain merge qualifier, else two merge regions * @throws IOException */ public static Pair<HRegionInfo, HRegionInfo> getRegionsFromMergeQualifier( Connection connection, byte[] regionName) throws IOException { Result result = getRegionResult(connection, regionName); HRegionInfo mergeA = getHRegionInfo(result, HConstants.MERGEA_QUALIFIER); HRegionInfo mergeB = getHRegionInfo(result, HConstants.MERGEB_QUALIFIER); if (mergeA == null && mergeB == null) { return null; } return new Pair<HRegionInfo, HRegionInfo>(mergeA, mergeB); } /** * Checks if the specified table exists. Looks at the hbase:meta table hosted on * the specified server. * @param connection connection we're using * @param tableName table to check * @return true if the table exists in meta, false if not * @throws IOException */ public static boolean tableExists(Connection connection, final TableName tableName) throws IOException { if (tableName.equals(TableName.META_TABLE_NAME)) { // Catalog tables always exist. return true; } // Make a version of ResultCollectingVisitor that only collects the first CollectingVisitor<HRegionInfo> visitor = new CollectingVisitor<HRegionInfo>() { private HRegionInfo current = null; @Override public boolean visit(Result r) throws IOException { RegionLocations locations = getRegionLocations(r); if (locations == null || locations.getRegionLocation().getRegionInfo() == null) { LOG.warn("No serialized HRegionInfo in " + r); return true; } this.current = locations.getRegionLocation().getRegionInfo(); if (this.current == null) { LOG.warn("No serialized HRegionInfo in " + r); return true; } if (!isInsideTable(this.current, tableName)) return false; // Else call super and add this Result to the collection. super.visit(r); // Stop collecting regions from table after we get one. return false; } @Override void add(Result r) { // Add the current HRI. this.results.add(this.current); } }; fullScan(connection, visitor, getTableStartRowForMeta(tableName)); // If visitor has results >= 1 then table exists. return visitor.getResults().size() >= 1; } /** * Gets all of the regions of the specified table. * @param zkw zookeeper connection to access meta table * @param connection connection we're using * @param tableName table we're looking for * @return Ordered list of {@link HRegionInfo}. * @throws IOException */ public static List<HRegionInfo> getTableRegions(ZooKeeperWatcher zkw, Connection connection, TableName tableName) throws IOException { return getTableRegions(zkw, connection, tableName, false); } /** * Gets all of the regions of the specified table. * @param zkw zookeeper connection to access meta table * @param connection connection we're using * @param tableName table we're looking for * @param excludeOfflinedSplitParents If true, do not include offlined split * parents in the return. * @return Ordered list of {@link HRegionInfo}. * @throws IOException */ public static List<HRegionInfo> getTableRegions(ZooKeeperWatcher zkw, Connection connection, TableName tableName, final boolean excludeOfflinedSplitParents) throws IOException { List<Pair<HRegionInfo, ServerName>> result = null; result = getTableRegionsAndLocations(zkw, connection, tableName, excludeOfflinedSplitParents); return getListOfHRegionInfos(result); } static List<HRegionInfo> getListOfHRegionInfos(final List<Pair<HRegionInfo, ServerName>> pairs) { if (pairs == null || pairs.isEmpty()) return null; List<HRegionInfo> result = new ArrayList<HRegionInfo>(pairs.size()); for (Pair<HRegionInfo, ServerName> pair : pairs) { result.add(pair.getFirst()); } return result; } /** * @param current region of current table we're working with * @param tableName table we're checking against * @return True if <code>current</code> tablename is equal to * <code>tableName</code> */ static boolean isInsideTable(final HRegionInfo current, final TableName tableName) { return tableName.equals(current.getTable()); } /** * @param tableName table we're working with * @return Place to start Scan in <code>hbase:meta</code> when passed a * <code>tableName</code>; returns <tableName&rt; <,&rt; <,&rt; */ static byte[] getTableStartRowForMeta(TableName tableName) { byte[] startRow = new byte[tableName.getName().length + 2]; System.arraycopy(tableName.getName(), 0, startRow, 0, tableName.getName().length); startRow[startRow.length - 2] = HConstants.DELIMITER; startRow[startRow.length - 1] = HConstants.DELIMITER; return startRow; } /** * This method creates a Scan object that will only scan catalog rows that * belong to the specified table. It doesn't specify any columns. * This is a better alternative to just using a start row and scan until * it hits a new table since that requires parsing the HRI to get the table * name. * @param tableName bytes of table's name * @return configured Scan object */ public static Scan getScanForTableName(TableName tableName) { String strName = tableName.getNameAsString(); // Start key is just the table name with delimiters byte[] startKey = Bytes.toBytes(strName + ",,"); // Stop key appends the smallest possible char to the table name byte[] stopKey = Bytes.toBytes(strName + " ,,"); Scan scan = new Scan(startKey); scan.setStopRow(stopKey); return scan; } /** * @param zkw zookeeper connection to access meta table * @param connection connection we're using * @param tableName table we're looking for * @return Return list of regioninfos and server. * @throws IOException */ public static List<Pair<HRegionInfo, ServerName>> getTableRegionsAndLocations(ZooKeeperWatcher zkw, Connection connection, TableName tableName) throws IOException { return getTableRegionsAndLocations(zkw, connection, tableName, true); } /** * @param zkw ZooKeeperWatcher instance we're using to get hbase:meta location * @param connection connection we're using * @param tableName table to work with * @return Return list of regioninfos and server addresses. * @throws IOException */ public static List<Pair<HRegionInfo, ServerName>> getTableRegionsAndLocations( ZooKeeperWatcher zkw, Connection connection, final TableName tableName, final boolean excludeOfflinedSplitParents) throws IOException { if (tableName.equals(TableName.META_TABLE_NAME)) { // If meta, do a bit of special handling. ServerName serverName = new MetaTableLocator().getMetaRegionLocation(zkw); List<Pair<HRegionInfo, ServerName>> list = new ArrayList<Pair<HRegionInfo, ServerName>>(); list.add(new Pair<HRegionInfo, ServerName>(HRegionInfo.FIRST_META_REGIONINFO, serverName)); return list; } // Make a version of CollectingVisitor that collects HRegionInfo and ServerAddress CollectingVisitor<Pair<HRegionInfo, ServerName>> visitor = new CollectingVisitor<Pair<HRegionInfo, ServerName>>() { private RegionLocations current = null; @Override public boolean visit(Result r) throws IOException { current = getRegionLocations(r); if (current == null || current.getRegionLocation().getRegionInfo() == null) { LOG.warn("No serialized HRegionInfo in " + r); return true; } HRegionInfo hri = current.getRegionLocation().getRegionInfo(); if (!isInsideTable(hri, tableName)) return false; if (excludeOfflinedSplitParents && hri.isSplitParent()) return true; // Else call super and add this Result to the collection. return super.visit(r); } @Override void add(Result r) { if (current == null) { return; } for (HRegionLocation loc : current.getRegionLocations()) { if (loc != null) { this.results.add(new Pair<HRegionInfo, ServerName>( loc.getRegionInfo(), loc.getServerName())); } } } }; fullScan(connection, visitor, getTableStartRowForMeta(tableName)); return visitor.getResults(); } /** * @param connection connection we're using * @param serverName server whose regions we're interested in * @return List of user regions installed on this server (does not include * catalog regions). * @throws IOException */ public static NavigableMap<HRegionInfo, Result> getServerUserRegions(Connection connection, final ServerName serverName) throws IOException { final NavigableMap<HRegionInfo, Result> hris = new TreeMap<HRegionInfo, Result>(); // Fill the above hris map with entries from hbase:meta that have the passed // servername. CollectingVisitor<Result> v = new CollectingVisitor<Result>() { @Override void add(Result r) { if (r == null || r.isEmpty()) return; RegionLocations locations = getRegionLocations(r); if (locations == null) return; for (HRegionLocation loc : locations.getRegionLocations()) { if (loc != null) { if (loc.getServerName() != null && loc.getServerName().equals(serverName)) { hris.put(loc.getRegionInfo(), r); } } } } }; fullScan(connection, v); return hris; } public static void fullScanMetaAndPrint(Connection connection) throws IOException { Visitor v = new Visitor() { @Override public boolean visit(Result r) throws IOException { if (r == null || r.isEmpty()) return true; LOG.info("fullScanMetaAndPrint.Current Meta Row: " + r); RegionLocations locations = getRegionLocations(r); if (locations == null) return true; for (HRegionLocation loc : locations.getRegionLocations()) { if (loc != null) { LOG.info("fullScanMetaAndPrint.HRI Print= " + loc.getRegionInfo()); } } return true; } }; fullScan(connection, v); } /** * Performs a full scan of a catalog table. * @param connection connection we're using * @param visitor Visitor invoked against each row. * @param startrow Where to start the scan. Pass null if want to begin scan * at first row. * <code>hbase:meta</code>, the default (pass false to scan hbase:meta) * @throws IOException */ public static void fullScan(Connection connection, final Visitor visitor, final byte[] startrow) throws IOException { Scan scan = new Scan(); if (startrow != null) scan.setStartRow(startrow); if (startrow == null) { int caching = connection.getConfiguration() .getInt(HConstants.HBASE_META_SCANNER_CACHING, 100); scan.setCaching(caching); } scan.addFamily(HConstants.CATALOG_FAMILY); Table metaTable = getMetaHTable(connection); ResultScanner scanner = null; try { scanner = metaTable.getScanner(scan); Result data; while ((data = scanner.next()) != null) { if (data.isEmpty()) continue; // Break if visit returns false. if (!visitor.visit(data)) break; } } finally { if (scanner != null) scanner.close(); metaTable.close(); } } /** * Returns the column family used for meta columns. * @return HConstants.CATALOG_FAMILY. */ protected static byte[] getFamily() { return HConstants.CATALOG_FAMILY; } /** * Returns the column qualifier for serialized region info * @return HConstants.REGIONINFO_QUALIFIER */ protected static byte[] getRegionInfoColumn() { return HConstants.REGIONINFO_QUALIFIER; } /** * Returns the column qualifier for server column for replicaId * @param replicaId the replicaId of the region * @return a byte[] for server column qualifier */ @VisibleForTesting public static byte[] getServerColumn(int replicaId) { return replicaId == 0 ? HConstants.SERVER_QUALIFIER : Bytes.toBytes(HConstants.SERVER_QUALIFIER_STR + META_REPLICA_ID_DELIMITER + String.format(HRegionInfo.REPLICA_ID_FORMAT, replicaId)); } /** * Returns the column qualifier for server start code column for replicaId * @param replicaId the replicaId of the region * @return a byte[] for server start code column qualifier */ @VisibleForTesting public static byte[] getStartCodeColumn(int replicaId) { return replicaId == 0 ? HConstants.STARTCODE_QUALIFIER : Bytes.toBytes(HConstants.STARTCODE_QUALIFIER_STR + META_REPLICA_ID_DELIMITER + String.format(HRegionInfo.REPLICA_ID_FORMAT, replicaId)); } /** * Returns the column qualifier for seqNum column for replicaId * @param replicaId the replicaId of the region * @return a byte[] for seqNum column qualifier */ @VisibleForTesting public static byte[] getSeqNumColumn(int replicaId) { return replicaId == 0 ? HConstants.SEQNUM_QUALIFIER : Bytes.toBytes(HConstants.SEQNUM_QUALIFIER_STR + META_REPLICA_ID_DELIMITER + String.format(HRegionInfo.REPLICA_ID_FORMAT, replicaId)); } /** * Parses the replicaId from the server column qualifier. See top of the class javadoc * for the actual meta layout * @param serverColumn the column qualifier * @return an int for the replicaId */ @VisibleForTesting static int parseReplicaIdFromServerColumn(byte[] serverColumn) { String serverStr = Bytes.toString(serverColumn); Matcher matcher = SERVER_COLUMN_PATTERN.matcher(serverStr); if (matcher.matches() && matcher.groupCount() > 0) { String group = matcher.group(1); if (group != null && group.length() > 0) { return Integer.parseInt(group.substring(1), 16); } else { return 0; } } return -1; } /** * Returns a {@link ServerName} from catalog table {@link Result}. * @param r Result to pull from * @return A ServerName instance or null if necessary fields not found or empty. */ private static ServerName getServerName(final Result r, final int replicaId) { byte[] serverColumn = getServerColumn(replicaId); Cell cell = r.getColumnLatestCell(getFamily(), serverColumn); if (cell == null || cell.getValueLength() == 0) return null; String hostAndPort = Bytes.toString( cell.getValueArray(), cell.getValueOffset(), cell.getValueLength()); byte[] startcodeColumn = getStartCodeColumn(replicaId); cell = r.getColumnLatestCell(getFamily(), startcodeColumn); if (cell == null || cell.getValueLength() == 0) return null; return ServerName.valueOf(hostAndPort, Bytes.toLong(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength())); } /** * The latest seqnum that the server writing to meta observed when opening the region. * E.g. the seqNum when the result of {@link #getServerName(Result, int)} was written. * @param r Result to pull the seqNum from * @return SeqNum, or HConstants.NO_SEQNUM if there's no value written. */ private static long getSeqNumDuringOpen(final Result r, final int replicaId) { Cell cell = r.getColumnLatestCell(getFamily(), getSeqNumColumn(replicaId)); if (cell == null || cell.getValueLength() == 0) return HConstants.NO_SEQNUM; return Bytes.toLong(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength()); } /** * Returns an HRegionLocationList extracted from the result. * @return an HRegionLocationList containing all locations for the region range or null if * we can't deserialize the result. */ public static RegionLocations getRegionLocations(final Result r) { if (r == null) return null; HRegionInfo regionInfo = getHRegionInfo(r, getRegionInfoColumn()); if (regionInfo == null) return null; List<HRegionLocation> locations = new ArrayList<HRegionLocation>(1); NavigableMap<byte[], NavigableMap<byte[], byte[]>> familyMap = r.getNoVersionMap(); locations.add(getRegionLocation(r, regionInfo, 0)); NavigableMap<byte[], byte[]> infoMap = familyMap.get(getFamily()); if (infoMap == null) return new RegionLocations(locations); // iterate until all serverName columns are seen int replicaId = 0; byte[] serverColumn = getServerColumn(replicaId); SortedMap<byte[], byte[]> serverMap = infoMap.tailMap(serverColumn, false); if (serverMap.isEmpty()) return new RegionLocations(locations); for (Map.Entry<byte[], byte[]> entry : serverMap.entrySet()) { replicaId = parseReplicaIdFromServerColumn(entry.getKey()); if (replicaId < 0) { break; } locations.add(getRegionLocation(r, regionInfo, replicaId)); } return new RegionLocations(locations); } /** * Returns the HRegionLocation parsed from the given meta row Result * for the given regionInfo and replicaId. The regionInfo can be the default region info * for the replica. * @param r the meta row result * @param regionInfo RegionInfo for default replica * @param replicaId the replicaId for the HRegionLocation * @return HRegionLocation parsed from the given meta row Result for the given replicaId */ private static HRegionLocation getRegionLocation(final Result r, final HRegionInfo regionInfo, final int replicaId) { ServerName serverName = getServerName(r, replicaId); long seqNum = getSeqNumDuringOpen(r, replicaId); HRegionInfo replicaInfo = RegionReplicaUtil.getRegionInfoForReplica(regionInfo, replicaId); return new HRegionLocation(replicaInfo, serverName, seqNum); } /** * Returns HRegionInfo object from the column * HConstants.CATALOG_FAMILY:HConstants.REGIONINFO_QUALIFIER of the catalog * table Result. * @param data a Result object from the catalog table scan * @return HRegionInfo or null */ public static HRegionInfo getHRegionInfo(Result data) { return getHRegionInfo(data, HConstants.REGIONINFO_QUALIFIER); } /** * Returns the HRegionInfo object from the column {@link HConstants#CATALOG_FAMILY} and * <code>qualifier</code> of the catalog table result. * @param r a Result object from the catalog table scan * @param qualifier Column family qualifier * @return An HRegionInfo instance or null. */ private static HRegionInfo getHRegionInfo(final Result r, byte[] qualifier) { Cell cell = r.getColumnLatestCell(getFamily(), qualifier); if (cell == null) return null; return HRegionInfo.parseFromOrNull(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength()); } /** * Returns the daughter regions by reading the corresponding columns of the catalog table * Result. * @param data a Result object from the catalog table scan * @return a pair of HRegionInfo or PairOfSameType(null, null) if the region is not a split * parent */ public static PairOfSameType<HRegionInfo> getDaughterRegions(Result data) { HRegionInfo splitA = getHRegionInfo(data, HConstants.SPLITA_QUALIFIER); HRegionInfo splitB = getHRegionInfo(data, HConstants.SPLITB_QUALIFIER); return new PairOfSameType<HRegionInfo>(splitA, splitB); } /** * Returns the merge regions by reading the corresponding columns of the catalog table * Result. * @param data a Result object from the catalog table scan * @return a pair of HRegionInfo or PairOfSameType(null, null) if the region is not a split * parent */ public static PairOfSameType<HRegionInfo> getMergeRegions(Result data) { HRegionInfo mergeA = getHRegionInfo(data, HConstants.MERGEA_QUALIFIER); HRegionInfo mergeB = getHRegionInfo(data, HConstants.MERGEB_QUALIFIER); return new PairOfSameType<HRegionInfo>(mergeA, mergeB); } /** * Implementations 'visit' a catalog table row. */ public interface Visitor { /** * Visit the catalog table row. * @param r A row from catalog table * @return True if we are to proceed scanning the table, else false if * we are to stop now. */ boolean visit(final Result r) throws IOException; } /** * A {@link Visitor} that collects content out of passed {@link Result}. */ static abstract class CollectingVisitor<T> implements Visitor { final List<T> results = new ArrayList<T>(); @Override public boolean visit(Result r) throws IOException { if (r == null || r.isEmpty()) return true; add(r); return true; } abstract void add(Result r); /** * @return Collected results; wait till visits complete to collect all * possible results */ List<T> getResults() { return this.results; } } /** * Collects all returned. */ static class CollectAllVisitor extends CollectingVisitor<Result> { @Override void add(Result r) { this.results.add(r); } } /** * Count regions in <code>hbase:meta</code> for passed table. * @param c Configuration object * @param tableName table name to count regions for * @return Count or regions in table <code>tableName</code> * @throws IOException */ @Deprecated public static int getRegionCount(final Configuration c, final String tableName) throws IOException { return getRegionCount(c, TableName.valueOf(tableName)); } /** * Count regions in <code>hbase:meta</code> for passed table. * @param c Configuration object * @param tableName table name to count regions for * @return Count or regions in table <code>tableName</code> * @throws IOException */ public static int getRegionCount(final Configuration c, final TableName tableName) throws IOException { try (Connection connection = ConnectionFactory.createConnection(c)) { return getRegionCount(connection, tableName); } } /** * Count regions in <code>hbase:meta</code> for passed table. * @param connection Connection object * @param tableName table name to count regions for * @return Count or regions in table <code>tableName</code> * @throws IOException */ public static int getRegionCount(final Connection connection, final TableName tableName) throws IOException { try (RegionLocator locator = connection.getRegionLocator(tableName)) { List<HRegionLocation> locations = locator.getAllRegionLocations(); return locations == null ? 0 : locations.size(); } } //////////////////////// // Editing operations // //////////////////////// /** * Generates and returns a Put containing the region into for the catalog table */ public static Put makePutFromRegionInfo(HRegionInfo regionInfo) throws IOException { Put put = new Put(regionInfo.getRegionName()); addRegionInfo(put, regionInfo); return put; } /** * Generates and returns a Delete containing the region info for the catalog * table */ public static Delete makeDeleteFromRegionInfo(HRegionInfo regionInfo) { if (regionInfo == null) { throw new IllegalArgumentException("Can't make a delete for null region"); } Delete delete = new Delete(regionInfo.getRegionName()); return delete; } /** * Adds split daughters to the Put */ public static Put addDaughtersToPut(Put put, HRegionInfo splitA, HRegionInfo splitB) { if (splitA != null) { put.addImmutable( HConstants.CATALOG_FAMILY, HConstants.SPLITA_QUALIFIER, splitA.toByteArray()); } if (splitB != null) { put.addImmutable( HConstants.CATALOG_FAMILY, HConstants.SPLITB_QUALIFIER, splitB.toByteArray()); } return put; } /** * Put the passed <code>p</code> to the <code>hbase:meta</code> table. * @param connection connection we're using * @param p Put to add to hbase:meta * @throws IOException */ static void putToMetaTable(final Connection connection, final Put p) throws IOException { put(getMetaHTable(connection), p); } /** * @param t Table to use (will be closed when done). * @param p put to make * @throws IOException */ private static void put(final Table t, final Put p) throws IOException { try { t.put(p); } finally { t.close(); } } /** * Put the passed <code>ps</code> to the <code>hbase:meta</code> table. * @param connection connection we're using * @param ps Put to add to hbase:meta * @throws IOException */ public static void putsToMetaTable(final Connection connection, final List<Put> ps) throws IOException { Table t = getMetaHTable(connection); try { t.put(ps); } finally { t.close(); } } /** * Delete the passed <code>d</code> from the <code>hbase:meta</code> table. * @param connection connection we're using * @param d Delete to add to hbase:meta * @throws IOException */ static void deleteFromMetaTable(final Connection connection, final Delete d) throws IOException { List<Delete> dels = new ArrayList<Delete>(1); dels.add(d); deleteFromMetaTable(connection, dels); } /** * Delete the passed <code>deletes</code> from the <code>hbase:meta</code> table. * @param connection connection we're using * @param deletes Deletes to add to hbase:meta This list should support #remove. * @throws IOException */ public static void deleteFromMetaTable(final Connection connection, final List<Delete> deletes) throws IOException { Table t = getMetaHTable(connection); try { t.delete(deletes); } finally { t.close(); } } /** * Deletes some replica columns corresponding to replicas for the passed rows * @param metaRows rows in hbase:meta * @param replicaIndexToDeleteFrom the replica ID we would start deleting from * @param numReplicasToRemove how many replicas to remove * @param connection connection we're using to access meta table * @throws IOException */ public static void removeRegionReplicasFromMeta(Set<byte[]> metaRows, int replicaIndexToDeleteFrom, int numReplicasToRemove, Connection connection) throws IOException { int absoluteIndex = replicaIndexToDeleteFrom + numReplicasToRemove; for (byte[] row : metaRows) { Delete deleteReplicaLocations = new Delete(row); for (int i = replicaIndexToDeleteFrom; i < absoluteIndex; i++) { deleteReplicaLocations.deleteColumns(HConstants.CATALOG_FAMILY, getServerColumn(i)); deleteReplicaLocations.deleteColumns(HConstants.CATALOG_FAMILY, getSeqNumColumn(i)); deleteReplicaLocations.deleteColumns(HConstants.CATALOG_FAMILY, getStartCodeColumn(i)); } deleteFromMetaTable(connection, deleteReplicaLocations); } } /** * Execute the passed <code>mutations</code> against <code>hbase:meta</code> table. * @param connection connection we're using * @param mutations Puts and Deletes to execute on hbase:meta * @throws IOException */ public static void mutateMetaTable(final Connection connection, final List<Mutation> mutations) throws IOException { Table t = getMetaHTable(connection); try { t.batch(mutations); } catch (InterruptedException e) { InterruptedIOException ie = new InterruptedIOException(e.getMessage()); ie.initCause(e); throw ie; } finally { t.close(); } } /** * Adds a hbase:meta row for the specified new region. * @param connection connection we're using * @param regionInfo region information * @throws IOException if problem connecting or updating meta */ public static void addRegionToMeta(Connection connection, HRegionInfo regionInfo) throws IOException { putToMetaTable(connection, makePutFromRegionInfo(regionInfo)); LOG.info("Added " + regionInfo.getRegionNameAsString()); } /** * Adds a hbase:meta row for the specified new region to the given catalog table. The * Table is not flushed or closed. * @param meta the Table for META * @param regionInfo region information * @throws IOException if problem connecting or updating meta */ public static void addRegionToMeta(Table meta, HRegionInfo regionInfo) throws IOException { addRegionToMeta(meta, regionInfo, null, null); } /** * Adds a (single) hbase:meta row for the specified new region and its daughters. Note that this * does not add its daughter's as different rows, but adds information about the daughters * in the same row as the parent. Use * {@link #splitRegion(org.apache.hadoop.hbase.client.Connection, * HRegionInfo, HRegionInfo, HRegionInfo, ServerName)} * if you want to do that. * @param meta the Table for META * @param regionInfo region information * @param splitA first split daughter of the parent regionInfo * @param splitB second split daughter of the parent regionInfo * @throws IOException if problem connecting or updating meta */ public static void addRegionToMeta(Table meta, HRegionInfo regionInfo, HRegionInfo splitA, HRegionInfo splitB) throws IOException { Put put = makePutFromRegionInfo(regionInfo); addDaughtersToPut(put, splitA, splitB); meta.put(put); if (LOG.isDebugEnabled()) { LOG.debug("Added " + regionInfo.getRegionNameAsString()); } } /** * Adds a (single) hbase:meta row for the specified new region and its daughters. Note that this * does not add its daughter's as different rows, but adds information about the daughters * in the same row as the parent. Use * {@link #splitRegion(Connection, HRegionInfo, HRegionInfo, HRegionInfo, ServerName)} * if you want to do that. * @param connection connection we're using * @param regionInfo region information * @param splitA first split daughter of the parent regionInfo * @param splitB second split daughter of the parent regionInfo * @throws IOException if problem connecting or updating meta */ public static void addRegionToMeta(Connection connection, HRegionInfo regionInfo, HRegionInfo splitA, HRegionInfo splitB) throws IOException { Table meta = getMetaHTable(connection); try { addRegionToMeta(meta, regionInfo, splitA, splitB); } finally { meta.close(); } } /** * Adds a hbase:meta row for each of the specified new regions. * @param connection connection we're using * @param regionInfos region information list * @throws IOException if problem connecting or updating meta */ public static void addRegionsToMeta(Connection connection, List<HRegionInfo> regionInfos) throws IOException { List<Put> puts = new ArrayList<Put>(); for (HRegionInfo regionInfo : regionInfos) { if (RegionReplicaUtil.isDefaultReplica(regionInfo)) { puts.add(makePutFromRegionInfo(regionInfo)); } } putsToMetaTable(connection, puts); LOG.info("Added " + puts.size()); } /** * Adds a daughter region entry to meta. * @param regionInfo the region to put * @param sn the location of the region * @param openSeqNum the latest sequence number obtained when the region was open */ public static void addDaughter(final Connection connection, final HRegionInfo regionInfo, final ServerName sn, final long openSeqNum) throws NotAllMetaRegionsOnlineException, IOException { Put put = new Put(regionInfo.getRegionName()); addRegionInfo(put, regionInfo); if (sn != null) { addLocation(put, sn, openSeqNum, regionInfo.getReplicaId()); } putToMetaTable(connection, put); LOG.info("Added daughter " + regionInfo.getEncodedName() + (sn == null ? ", serverName=null" : ", serverName=" + sn.toString())); } /** * Merge the two regions into one in an atomic operation. Deletes the two * merging regions in hbase:meta and adds the merged region with the information of * two merging regions. * @param connection connection we're using * @param mergedRegion the merged region * @param regionA * @param regionB * @param sn the location of the region * @throws IOException */ public static void mergeRegions(final Connection connection, HRegionInfo mergedRegion, HRegionInfo regionA, HRegionInfo regionB, ServerName sn) throws IOException { Table meta = getMetaHTable(connection); try { HRegionInfo copyOfMerged = new HRegionInfo(mergedRegion); // Put for parent Put putOfMerged = makePutFromRegionInfo(copyOfMerged); putOfMerged.addImmutable(HConstants.CATALOG_FAMILY, HConstants.MERGEA_QUALIFIER, regionA.toByteArray()); putOfMerged.addImmutable(HConstants.CATALOG_FAMILY, HConstants.MERGEB_QUALIFIER, regionB.toByteArray()); // Deletes for merging regions Delete deleteA = makeDeleteFromRegionInfo(regionA); Delete deleteB = makeDeleteFromRegionInfo(regionB); // The merged is a new region, openSeqNum = 1 is fine. addLocation(putOfMerged, sn, 1, mergedRegion.getReplicaId()); byte[] tableRow = Bytes.toBytes(mergedRegion.getRegionNameAsString() + HConstants.DELIMITER); multiMutate(meta, tableRow, putOfMerged, deleteA, deleteB); } finally { meta.close(); } } /** * Splits the region into two in an atomic operation. Offlines the parent * region with the information that it is split into two, and also adds * the daughter regions. Does not add the location information to the daughter * regions since they are not open yet. * @param connection connection we're using * @param parent the parent region which is split * @param splitA Split daughter region A * @param splitB Split daughter region A * @param sn the location of the region */ public static void splitRegion(final Connection connection, HRegionInfo parent, HRegionInfo splitA, HRegionInfo splitB, ServerName sn) throws IOException { Table meta = getMetaHTable(connection); try { HRegionInfo copyOfParent = new HRegionInfo(parent); copyOfParent.setOffline(true); copyOfParent.setSplit(true); //Put for parent Put putParent = makePutFromRegionInfo(copyOfParent); addDaughtersToPut(putParent, splitA, splitB); //Puts for daughters Put putA = makePutFromRegionInfo(splitA); Put putB = makePutFromRegionInfo(splitB); addLocation(putA, sn, 1, splitA.getReplicaId()); //new regions, openSeqNum = 1 is fine. addLocation(putB, sn, 1, splitB.getReplicaId()); byte[] tableRow = Bytes.toBytes(parent.getRegionNameAsString() + HConstants.DELIMITER); multiMutate(meta, tableRow, putParent, putA, putB); } finally { meta.close(); } } /** * Performs an atomic multi-Mutate operation against the given table. */ private static void multiMutate(Table table, byte[] row, Mutation... mutations) throws IOException { CoprocessorRpcChannel channel = table.coprocessorService(row); MultiRowMutationProtos.MutateRowsRequest.Builder mmrBuilder = MultiRowMutationProtos.MutateRowsRequest.newBuilder(); for (Mutation mutation : mutations) { if (mutation instanceof Put) { mmrBuilder.addMutationRequest(ProtobufUtil.toMutation( ClientProtos.MutationProto.MutationType.PUT, mutation)); } else if (mutation instanceof Delete) { mmrBuilder.addMutationRequest(ProtobufUtil.toMutation( ClientProtos.MutationProto.MutationType.DELETE, mutation)); } else { throw new DoNotRetryIOException("multi in MetaEditor doesn't support " + mutation.getClass().getName()); } } MultiRowMutationProtos.MultiRowMutationService.BlockingInterface service = MultiRowMutationProtos.MultiRowMutationService.newBlockingStub(channel); try { service.mutateRows(null, mmrBuilder.build()); } catch (ServiceException ex) { ProtobufUtil.toIOException(ex); } } /** * Updates the location of the specified region in hbase:meta to be the specified * server hostname and startcode. * <p> * Uses passed catalog tracker to get a connection to the server hosting * hbase:meta and makes edits to that region. * * @param connection connection we're using * @param regionInfo region to update location of * @param sn Server name * @throws IOException */ public static void updateRegionLocation(Connection connection, HRegionInfo regionInfo, ServerName sn, long updateSeqNum) throws IOException { updateLocation(connection, regionInfo, sn, updateSeqNum); } /** * Updates the location of the specified region to be the specified server. * <p> * Connects to the specified server which should be hosting the specified * catalog region name to perform the edit. * * @param connection connection we're using * @param regionInfo region to update location of * @param sn Server name * @param openSeqNum the latest sequence number obtained when the region was open * @throws IOException In particular could throw {@link java.net.ConnectException} * if the server is down on other end. */ private static void updateLocation(final Connection connection, HRegionInfo regionInfo, ServerName sn, long openSeqNum) throws IOException { // region replicas are kept in the primary region's row Put put = new Put(getMetaKeyForRegion(regionInfo)); addLocation(put, sn, openSeqNum, regionInfo.getReplicaId()); putToMetaTable(connection, put); LOG.info("Updated row " + regionInfo.getRegionNameAsString() + " with server=" + sn); } /** * Deletes the specified region from META. * @param connection connection we're using * @param regionInfo region to be deleted from META * @throws IOException */ public static void deleteRegion(Connection connection, HRegionInfo regionInfo) throws IOException { Delete delete = new Delete(regionInfo.getRegionName()); deleteFromMetaTable(connection, delete); LOG.info("Deleted " + regionInfo.getRegionNameAsString()); } /** * Deletes the specified regions from META. * @param connection connection we're using * @param regionsInfo list of regions to be deleted from META * @throws IOException */ public static void deleteRegions(Connection connection, List<HRegionInfo> regionsInfo) throws IOException { List<Delete> deletes = new ArrayList<Delete>(regionsInfo.size()); for (HRegionInfo hri : regionsInfo) { deletes.add(new Delete(hri.getRegionName())); } deleteFromMetaTable(connection, deletes); LOG.info("Deleted " + regionsInfo); } /** * Adds and Removes the specified regions from hbase:meta * @param connection connection we're using * @param regionsToRemove list of regions to be deleted from META * @param regionsToAdd list of regions to be added to META * @throws IOException */ public static void mutateRegions(Connection connection, final List<HRegionInfo> regionsToRemove, final List<HRegionInfo> regionsToAdd) throws IOException { List<Mutation> mutation = new ArrayList<Mutation>(); if (regionsToRemove != null) { for (HRegionInfo hri : regionsToRemove) { mutation.add(new Delete(hri.getRegionName())); } } if (regionsToAdd != null) { for (HRegionInfo hri : regionsToAdd) { mutation.add(makePutFromRegionInfo(hri)); } } mutateMetaTable(connection, mutation); if (regionsToRemove != null && regionsToRemove.size() > 0) { LOG.debug("Deleted " + regionsToRemove); } if (regionsToAdd != null && regionsToAdd.size() > 0) { LOG.debug("Added " + regionsToAdd); } } /** * Overwrites the specified regions from hbase:meta * @param connection connection we're using * @param regionInfos list of regions to be added to META * @throws IOException */ public static void overwriteRegions(Connection connection, List<HRegionInfo> regionInfos) throws IOException { deleteRegions(connection, regionInfos); // Why sleep? This is the easiest way to ensure that the previous deletes does not // eclipse the following puts, that might happen in the same ts from the server. // See HBASE-9906, and HBASE-9879. Once either HBASE-9879, HBASE-8770 is fixed, // or HBASE-9905 is fixed and meta uses seqIds, we do not need the sleep. Threads.sleep(20); addRegionsToMeta(connection, regionInfos); LOG.info("Overwritten " + regionInfos); } /** * Deletes merge qualifiers for the specified merged region. * @param connection connection we're using * @param mergedRegion * @throws IOException */ public static void deleteMergeQualifiers(Connection connection, final HRegionInfo mergedRegion) throws IOException { Delete delete = new Delete(mergedRegion.getRegionName()); delete.deleteColumns(HConstants.CATALOG_FAMILY, HConstants.MERGEA_QUALIFIER); delete.deleteColumns(HConstants.CATALOG_FAMILY, HConstants.MERGEB_QUALIFIER); deleteFromMetaTable(connection, delete); LOG.info("Deleted references in merged region " + mergedRegion.getRegionNameAsString() + ", qualifier=" + Bytes.toStringBinary(HConstants.MERGEA_QUALIFIER) + " and qualifier=" + Bytes.toStringBinary(HConstants.MERGEB_QUALIFIER)); } private static Put addRegionInfo(final Put p, final HRegionInfo hri) throws IOException { p.addImmutable(HConstants.CATALOG_FAMILY, HConstants.REGIONINFO_QUALIFIER, hri.toByteArray()); //String schema = new String();//add the schema of table this hregion holds //p.addImmutable(HConstants.CATALOG_FAMILY, HConstants.SCHEMA_QUALIFIER, Bytes.toBytes(schema)); return p; } public static Put addLocation(final Put p, final ServerName sn, long openSeqNum, int replicaId) { // using regionserver's local time as the timestamp of Put. // See: HBASE-11536 long now = EnvironmentEdgeManager.currentTime(); p.addImmutable(HConstants.CATALOG_FAMILY, getServerColumn(replicaId), now, Bytes.toBytes(sn.getHostAndPort())); p.addImmutable(HConstants.CATALOG_FAMILY, getStartCodeColumn(replicaId), now, Bytes.toBytes(sn.getStartcode())); p.addImmutable(HConstants.CATALOG_FAMILY, getSeqNumColumn(replicaId), now, Bytes.toBytes(openSeqNum)); return p; } /**######################### functions for parquet ###############################*/ /** * Generates and returns a Put containing the region into for the catalog table * @param schema table schema info * @author Wang Xiaoyi */ public static Put makePutFromRegionInfo(HRegionInfo regionInfo, String schema) throws IOException { Put put = new Put(regionInfo.getRegionName()); addRegionInfo(put, regionInfo, schema); return put; } /** * @author Wang Xiaoyi * Adds a hbase:meta row for each of the specified new regions. * @param connection connection we're using * @param regionInfos region information list * @param schema schema of table this region belongs to * @throws IOException */ public static void addRegionsToMeta(Connection connection, List<HRegionInfo> regionInfos, String schema) throws IOException{ List<Put> puts = new ArrayList<Put>(); for (HRegionInfo regionInfo : regionInfos) { if (RegionReplicaUtil.isDefaultReplica(regionInfo)) { puts.add(makePutFromRegionInfo(regionInfo, schema)); } } putsToMetaTable(connection, puts); LOG.info("Added " + puts.size()); } /** * add region info to meta encapusulated in put * @author Wang Xiaoyi * @param p * @param hri * @param schema table schema * @return * @throws IOException */ private static Put addRegionInfo(final Put p, final HRegionInfo hri, String schema) throws IOException { p.addImmutable(HConstants.CATALOG_FAMILY, HConstants.REGIONINFO_QUALIFIER, hri.toByteArray()); p.addImmutable(HConstants.CATALOG_FAMILY, HConstants.SCHEMA_QUALIFIER, Bytes.toBytes(schema)); return p; } public static String getTableSchema(TableName tableName){ String schema = null; //Get get = new Get(); return schema; } /** * get schema for region * @param hri * @param connection * @return * @throws IOException * @throws SchemaNotFoundException */ public static String getSchemaForRegion(final HRegionInfo hri, final Connection connection) throws IOException, SchemaNotFoundException{ String schema = null; Get get = new Get(hri.getRegionName()); Result rs = get(connection.getTable(hri.getTable()), get); List<Cell> cells = rs.getColumnCells(HConstants.CATALOG_FAMILY, HConstants.SCHEMA_QUALIFIER); if(cells.size() > 0){ schema = Bytes.toString(cells.get(cells.size() - 1).getValueArray()); }else { LOG.error(hri.getRegionName()+" region schema not found!"); throw new SchemaNotFoundException(); } return schema; } }