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    private static final Logger logger = LoggerFactory.getLogger(ConnectionQueryServicesImpl.class);

    private static final int INITIAL_CHILD_SERVICES_CAPACITY = 100;

    private static final int DEFAULT_OUT_OF_ORDER_MUTATIONS_WAIT_TIME_MS = 1000;

    protected final Configuration config;

    // Copy of config.getProps(), but read-only to prevent synchronization that we

    // don't need.

    private final ReadOnlyProps props;

    private final HConnection connection;

    private final StatsManager statsManager;

    private final ConcurrentHashMap<ImmutableBytesWritable,ConnectionQueryServices> childServices;

    // Cache the latest meta data here for future connections

    private volatile PMetaData latestMetaData = PMetaDataImpl.EMPTY_META_DATA;

    private final Object latestMetaDataLock = new Object();

    // Lowest HBase version on the cluster.

    private int lowestClusterHBaseVersion = Integer.MAX_VALUE;

    private boolean hasInvalidIndexConfiguration = false;

    private int connectionCount = 0;

   

    private ConcurrentMap<SequenceKey,Sequence> sequenceMap = Maps.newConcurrentMap();

    private KeyValueBuilder kvBuilder;

    /**

     * Construct a ConnectionQueryServicesImpl that represents a connection to an HBase

     * cluster.

     * @param services base services from where we derive our default configuration

     * @param connectionInfo to provide connection information

     * @throws SQLException

     */

    public ConnectionQueryServicesImpl(QueryServices services, ConnectionInfo connectionInfo) throws SQLException {

        super(services);

        Configuration config = HBaseFactoryProvider.getConfigurationFactory().getConfiguration();

        for (Entry<String,String> entry : services.getProps()) {

            config.set(entry.getKey(), entry.getValue());

        }

        for (Entry<String,String> entry : connectionInfo.asProps()) {

            config.set(entry.getKey(), entry.getValue());

        }

        // Without making a copy of the configuration we cons up, we lose some of our properties

        // on the server side during testing.

        this.config = HBaseConfiguration.create(config);

        this.props = new ReadOnlyProps(this.config.iterator());

        try {

            this.connection = HBaseFactoryProvider.getHConnectionFactory().createConnection(this.config);

        } catch (ZooKeeperConnectionException e) {

            throw new SQLExceptionInfo.Builder(SQLExceptionCode.CANNOT_ESTABLISH_CONNECTION)

                .setRootCause(e).build().buildException();

        }

        if (this.connection.isClosed()) { // TODO: why the heck doesn't this throw above?

            throw new SQLExceptionInfo.Builder(SQLExceptionCode.CANNOT_ESTABLISH_CONNECTION).build().buildException();

        }

        // TODO: should we track connection wide memory usage or just org-wide usage?

        // If connection-wide, create a MemoryManager here, otherwise just use the one from the delegate

        this.childServices = new ConcurrentHashMap<ImmutableBytesWritable,ConnectionQueryServices>(INITIAL_CHILD_SERVICES_CAPACITY);

        int statsUpdateFrequencyMs = this.getProps().getInt(QueryServices.STATS_UPDATE_FREQ_MS_ATTRIB, QueryServicesOptions.DEFAULT_STATS_UPDATE_FREQ_MS);

        int maxStatsAgeMs = this.getProps().getInt(QueryServices.MAX_STATS_AGE_MS_ATTRIB, QueryServicesOptions.DEFAULT_MAX_STATS_AGE_MS);

        this.statsManager = new StatsManagerImpl(this, statsUpdateFrequencyMs, maxStatsAgeMs);

        // find the HBase version and use that to determine the KeyValueBuilder that should be used

        String hbaseVersion = VersionInfo.getVersion();

        this.kvBuilder = KeyValueBuilder.get(hbaseVersion);

    }

    @Override

    public StatsManager getStatsManager() {

        return this.statsManager;

    }

   

    @Override

    public HTableInterface getTable(byte[] tableName) throws SQLException {

        try {

            return HBaseFactoryProvider.getHTableFactory().getTable(tableName, connection, getExecutor());

        } catch (org.apache.hadoop.hbase.TableNotFoundException e) {

            byte[][] schemaAndTableName = new byte[2][];

            SchemaUtil.getVarChars(tableName, schemaAndTableName);

            throw new TableNotFoundException(Bytes.toString(schemaAndTableName[0]), Bytes.toString(schemaAndTableName[1]));

        } catch (IOException e) {

            throw new RuntimeException(e);

        }

    }

   

    @Override

    public HTableDescriptor getTableDescriptor(byte[] tableName) throws SQLException {

        try {

            return getTable(tableName).getTableDescriptor();

        } catch (IOException e) {

            throw new RuntimeException(e);

        }

    }

    @Override

    public ReadOnlyProps getProps() {

        return props;

    }

    /**

     * Closes the underlying connection to zookeeper. The QueryServices

     * may not be used after that point. When a Connection is closed,

     * this is not called, since these instances are pooled by the

     * Driver. Instead, the Driver should call this if the QueryServices

     * is ever removed from the pool

     */

    @Override

    public void close() throws SQLException {

        SQLException sqlE = null;

        try {

            // Clear Phoenix metadata cache before closing HConnection

            clearCache();

        } catch (SQLException e) {

            sqlE = e;

        } finally {

            try {

                connection.close();

            } catch (IOException e) {

                if (sqlE == null) {

                    sqlE = ServerUtil.parseServerException(e);

                } else {

                    sqlE.setNextException(ServerUtil.parseServerException(e));

                }

                throw sqlE;

            } finally {

                super.close();

            }

        }

    }   

    protected ConnectionQueryServices newChildQueryService() {

        return new ChildQueryServices(this);

    }

    /**

     * Get (and create if necessary) a child QueryService for a given tenantId.

     * The QueryService will be cached for the lifetime of the parent QueryService

     * @param tenantId the tenant ID

     * @return the child QueryService

     */

    @Override

    public ConnectionQueryServices getChildQueryServices(ImmutableBytesWritable tenantId) {

        ConnectionQueryServices childQueryService = childServices.get(tenantId);

        if (childQueryService == null) {

            childQueryService = newChildQueryService();

            ConnectionQueryServices prevQueryService = childServices.putIfAbsent(tenantId, childQueryService);

            return prevQueryService == null ? childQueryService : prevQueryService;

        }

        return childQueryService;

    }

    @Override

    public void clearTableRegionCache(byte[] tableName) throws SQLException {

        connection.clearRegionCache(tableName);

    }

   

    @Override

    public List<HRegionLocation> getAllTableRegions(byte[] tableName) throws SQLException {

        /*

         * Use HConnection.getRegionLocation as it uses the cache in HConnection, while getting

         * all region locations from the HTable doesn't.

         */

        int retryCount = 0, maxRetryCount = 1;

        boolean reload =false;

        while (true) {

            try {

                // We could surface the package projected HConnectionImplementation.getNumberOfCachedRegionLocations

                // to get the sizing info we need, but this would require a new class in the same package and a cast

                // to this implementation class, so it's probably not worth it.

                List<HRegionLocation> locations = Lists.newArrayList();

                byte[] currentKey = HConstants.EMPTY_START_ROW;

                do {

                  HRegionLocation regionLocation = connection.getRegionLocation(tableName, currentKey, reload);

                  locations.add(regionLocation);

                  currentKey = regionLocation.getRegionInfo().getEndKey();

                } while (!Bytes.equals(currentKey, HConstants.EMPTY_END_ROW));

                return locations;

            } catch (IOException e) {

                if (retryCount++ < maxRetryCount) { // One retry, in case split occurs while navigating

                    reload = true;

                    continue;

                }

                throw new SQLExceptionInfo.Builder(SQLExceptionCode.GET_TABLE_REGIONS_FAIL)

                    .setRootCause(e).build().buildException();

            }

        }

    }

    @Override

    public PMetaData addTable(PTable table) throws SQLException {

        try {

            // If existing table isn't older than new table, don't replace

            // If a client opens a connection at an earlier timestamp, this can happen

            PTable existingTable = latestMetaData.getTable(table.getName().getString());

            if (existingTable.getTimeStamp() >= table.getTimeStamp()) {

                return latestMetaData;

            }

        } catch (TableNotFoundException e) {

        }

        synchronized(latestMetaDataLock) {

            latestMetaData = latestMetaData.addTable(table);

            latestMetaDataLock.notifyAll();

            return latestMetaData;

        }

    }

    private static interface Mutator {

        PMetaData mutate(PMetaData metaData) throws SQLException;

    }

    /**

     * Ensures that metaData mutations are handled in the correct order

     */

    private PMetaData metaDataMutated(String tableName, long tableSeqNum, Mutator mutator) throws SQLException {

        synchronized(latestMetaDataLock) {

            PMetaData metaData = latestMetaData;

            PTable table;

            long endTime = System.currentTimeMillis() + DEFAULT_OUT_OF_ORDER_MUTATIONS_WAIT_TIME_MS;

            while (true) {

                try {

                    try {

                        table = metaData.getTable(tableName);

                        /* If the table is at the prior sequence number, then we're good to go.

                         * We know if we've got this far, that the server validated the mutations,

                         * so we'd just need to wait until the other connection that mutated the same

                         * table is processed.

                         */

                        if (table.getSequenceNumber() + 1 == tableSeqNum) {

                            // TODO: assert that timeStamp is bigger that table timeStamp?

                            metaData = mutator.mutate(metaData);

                            break;

                        } else if (table.getSequenceNumber() >= tableSeqNum) {

                            logger.warn("Attempt to cache older version of " + tableName + ": current= " + table.getSequenceNumber() + ", new=" + tableSeqNum);

                            break;

                        }

                    } catch (TableNotFoundException e) {

                    }

                    long waitTime = endTime - System.currentTimeMillis();

                    // We waited long enough - just remove the table from the cache

                    // and the next time it's used it'll be pulled over from the server.

                    if (waitTime <= 0) {

                        logger.warn("Unable to update meta data repo within " + (DEFAULT_OUT_OF_ORDER_MUTATIONS_WAIT_TIME_MS/1000) + " seconds for " + tableName);

                        metaData = metaData.removeTable(tableName);

                        break;

                    }

                    latestMetaDataLock.wait(waitTime);

                } catch (InterruptedException e) {

                    throw new SQLExceptionInfo.Builder(SQLExceptionCode.INTERRUPTED_EXCEPTION)

                        .setRootCause(e).build().buildException(); // FIXME

                }

            }

            latestMetaData = metaData;

            latestMetaDataLock.notifyAll();

            return metaData;

        }

     }

    @Override

    public PMetaData addColumn(final String tableName, final List<PColumn> columns, final long tableTimeStamp, final long tableSeqNum, final boolean isImmutableRows) throws SQLException {

        return metaDataMutated(tableName, tableSeqNum, new Mutator() {

            @Override

            public PMetaData mutate(PMetaData metaData) throws SQLException {

                try {

                    return metaData.addColumn(tableName, columns, tableTimeStamp, tableSeqNum, isImmutableRows);

                } catch (TableNotFoundException e) {

                    // The DROP TABLE may have been processed first, so just ignore.

                    return metaData;

                }

            }

        });

     }

    @Override

    public PMetaData removeTable(final String tableName) throws SQLException {

        synchronized(latestMetaDataLock) {

            latestMetaData = latestMetaData.removeTable(tableName);

            latestMetaDataLock.notifyAll();

            return latestMetaData;

        }

    }

    @Override

    public PMetaData removeColumn(final String tableName, final String familyName, final String columnName, final long tableTimeStamp, final long tableSeqNum) throws SQLException {

        return metaDataMutated(tableName, tableSeqNum, new Mutator() {

            @Override

            public PMetaData mutate(PMetaData metaData) throws SQLException {

                try {

                    return metaData.removeColumn(tableName, familyName, columnName, tableTimeStamp, tableSeqNum);

                } catch (TableNotFoundException e) {

                    // The DROP TABLE may have been processed first, so just ignore.

                    return metaData;

                }

            }

        });

    }

    @Override

    public PhoenixConnection connect(String url, Properties info) throws SQLException {

        Long scn = JDBCUtil.getCurrentSCN(url, info);

        PMetaData metaData = scn == null ? latestMetaData : PMetaDataImpl.pruneNewerTables(scn, latestMetaData);

        return new PhoenixConnection(this, url, info, metaData);

    }

    private HColumnDescriptor generateColumnFamilyDescriptor(Pair<byte[],Map<String,Object>> family, PTableType tableType) throws SQLException {

        HColumnDescriptor columnDesc = new HColumnDescriptor(family.getFirst());

        if (tableType != PTableType.VIEW) {

            columnDesc.setKeepDeletedCells(true);

            columnDesc.setDataBlockEncoding(SchemaUtil.DEFAULT_DATA_BLOCK_ENCODING);

            for (Entry<String,Object> entry : family.getSecond().entrySet()) {

                String key = entry.getKey();

                Object value = entry.getValue();

                columnDesc.setValue(key, value == null ? null : value.toString());

            }

        }

        return columnDesc;

    }

    private void modifyColumnFamilyDescriptor(HColumnDescriptor hcd, Pair<byte[],Map<String,Object>> family) throws SQLException {

      for (Entry<String, Object> entry : family.getSecond().entrySet()) {

        String key = entry.getKey();

        Object value = entry.getValue();

        hcd.setValue(key, value == null ? null : value.toString());

      }

      hcd.setKeepDeletedCells(true);

    }

   

    private HTableDescriptor generateTableDescriptor(byte[] tableName, HTableDescriptor existingDesc, PTableType tableType, Map<String,Object> tableProps, List<Pair<byte[],Map<String,Object>>> families, byte[][] splits) throws SQLException {

        HTableDescriptor descriptor = (existingDesc != null) ? new HTableDescriptor(existingDesc) : new HTableDescriptor(tableName);

        for (Entry<String,Object> entry : tableProps.entrySet()) {

            String key = entry.getKey();

            Object value = entry.getValue();

            descriptor.setValue(key, value == null ? null : value.toString());

        }

        if (families.isEmpty()) {

            if (tableType != PTableType.VIEW) {

                // Add dummy column family so we have key values for tables that

                HColumnDescriptor columnDescriptor = generateColumnFamilyDescriptor(new Pair<byte[],Map<String,Object>>(QueryConstants.EMPTY_COLUMN_BYTES,Collections.<String,Object>emptyMap()), tableType);

                descriptor.addFamily(columnDescriptor);

            }

        } else {

            for (Pair<byte[],Map<String,Object>> family : families) {

                // If family is only in phoenix description, add it. otherwise, modify its property accordingly.

                byte[] familyByte = family.getFirst();

                if (descriptor.getFamily(familyByte) == null) {

                    if (tableType == PTableType.VIEW) {

                        String fullTableName = Bytes.toString(tableName);

                        throw new ReadOnlyTableException(

                                "The HBase column families for a read-only table must already exist",

                                SchemaUtil.getSchemaNameFromFullName(fullTableName),

                                SchemaUtil.getTableNameFromFullName(fullTableName),

                                Bytes.toString(familyByte));

                    }

                    HColumnDescriptor columnDescriptor = generateColumnFamilyDescriptor(family, tableType);

                    descriptor.addFamily(columnDescriptor);

                } else {

                    if (tableType != PTableType.VIEW) {

                        modifyColumnFamilyDescriptor(descriptor.getFamily(familyByte), family);

                    }

                }

            }

        }

        // The phoenix jar must be available on HBase classpath

        try {

            if (!descriptor.hasCoprocessor(ScanRegionObserver.class.getName())) {

                descriptor.addCoprocessor(ScanRegionObserver.class.getName(), null, 1, null);

            }

            if (!descriptor.hasCoprocessor(UngroupedAggregateRegionObserver.class.getName())) {

                descriptor.addCoprocessor(UngroupedAggregateRegionObserver.class.getName(), null, 1, null);

            }

            if (!descriptor.hasCoprocessor(GroupedAggregateRegionObserver.class.getName())) {

                descriptor.addCoprocessor(GroupedAggregateRegionObserver.class.getName(), null, 1, null);

            }

            if (!descriptor.hasCoprocessor(ServerCachingEndpointImpl.class.getName())) {

                descriptor.addCoprocessor(ServerCachingEndpointImpl.class.getName(), null, 1, null);

            }

            // TODO: better encapsulation for this

            // Since indexes can't have indexes, don't install our indexing coprocessor for indexes. Also,

            // don't install on the metadata table until we fix the TODO there.

            if (tableType != PTableType.INDEX && !descriptor.hasCoprocessor(Indexer.class.getName())

                  && !SchemaUtil.isMetaTable(tableName) && !SchemaUtil.isSequenceTable(tableName)) {

                Map<String, String> opts = Maps.newHashMapWithExpectedSize(1);

                opts.put(CoveredColumnsIndexBuilder.CODEC_CLASS_NAME_KEY, PhoenixIndexCodec.class.getName());

                Indexer.enableIndexing(descriptor, PhoenixIndexBuilder.class, opts);

            }

           

            // Setup split policy on Phoenix metadata table to ensure that the key values of a Phoenix table

            // stay on the same region.

            if (SchemaUtil.isMetaTable(tableName)) {

                descriptor.setValue(SchemaUtil.UPGRADE_TO_2_0, Boolean.TRUE.toString());

                descriptor.setValue(SchemaUtil.UPGRADE_TO_2_1, Boolean.TRUE.toString());

                descriptor.setValue(SchemaUtil.UPGRADE_TO_3_0, Boolean.TRUE.toString());

                if (!descriptor.hasCoprocessor(MetaDataEndpointImpl.class.getName())) {

                    descriptor.addCoprocessor(MetaDataEndpointImpl.class.getName(), null, 1, null);

                }

                if (!descriptor.hasCoprocessor(MetaDataRegionObserver.class.getName())) {

                    descriptor.addCoprocessor(MetaDataRegionObserver.class.getName(), null, 2, null);

                }

            } else if (SchemaUtil.isSequenceTable(tableName)) {

                if (!descriptor.hasCoprocessor(SequenceRegionObserver.class.getName())) {

                    descriptor.addCoprocessor(SequenceRegionObserver.class.getName(), null, 1, null);

                }

            }

        } catch (IOException e) {

            throw ServerUtil.parseServerException(e);

        }

        return descriptor;

    }

    private void ensureFamilyCreated(byte[] tableName, PTableType tableType , Pair<byte[],Map<String,Object>> family) throws SQLException {

        HBaseAdmin admin = null;

        SQLException sqlE = null;

        try {

            admin = new HBaseAdmin(config);

            try {

                HTableDescriptor existingDesc = admin.getTableDescriptor(tableName);

                HColumnDescriptor oldDescriptor = existingDesc.getFamily(family.getFirst());

                HColumnDescriptor columnDescriptor = null;

                if (oldDescriptor == null) {

                    if (tableType == PTableType.VIEW) {

                        String fullTableName = Bytes.toString(tableName);

                        throw new ReadOnlyTableException(

                                "The HBase column families for a read-only table must already exist",

                                SchemaUtil.getSchemaNameFromFullName(fullTableName),

                                SchemaUtil.getTableNameFromFullName(fullTableName),

                                Bytes.toString(family.getFirst()));

                    }

                    columnDescriptor = generateColumnFamilyDescriptor(family, tableType );

                } else {

                    columnDescriptor = new HColumnDescriptor(oldDescriptor);

                    if (tableType != PTableType.VIEW) {

                        modifyColumnFamilyDescriptor(columnDescriptor, family);

                    }

                }

               

                if (columnDescriptor.equals(oldDescriptor)) {

                    // Table already has family and it's the same.

                    return;

                }

                admin.disableTable(tableName);

                if (oldDescriptor == null) {

                    admin.addColumn(tableName, columnDescriptor);

                } else {

                    admin.modifyColumn(tableName, columnDescriptor);

                }

                admin.enableTable(tableName);

            } catch (org.apache.hadoop.hbase.TableNotFoundException e) {

                sqlE = new SQLExceptionInfo.Builder(SQLExceptionCode.TABLE_UNDEFINED).setRootCause(e).build().buildException();

            }

        } catch (IOException e) {

            sqlE = ServerUtil.parseServerException(e);

        } finally {

            try {

                if (admin != null) {

                    admin.close();

                }

            } catch (IOException e) {

                if (sqlE == null) {

                    sqlE = ServerUtil.parseServerException(e);

                } else {

                    sqlE.setNextException(ServerUtil.parseServerException(e));

                }

            } finally {

                if (sqlE != null) {

                    throw sqlE;

                }

            }

        }

    }

   

    /**

     *

     * @param tableName

     * @param familyNames

     * @param splits

     * @return true if table was created and false if it already exists

     * @throws SQLException

     */

    private boolean ensureTableCreated(byte[] tableName, PTableType tableType , Map<String,Object> props, List<Pair<byte[],Map<String,Object>>> families, byte[][] splits) throws SQLException {

        HBaseAdmin admin = null;

        SQLException sqlE = null;

        HTableDescriptor existingDesc = null;

        boolean isMetaTable = SchemaUtil.isMetaTable(tableName);

        boolean tableExist = true;

        try {

            System.out.println("Found quorum: " + ZKConfig.getZKQuorumServersString(config));

            admin = new HBaseAdmin(config);

            try {

                existingDesc = admin.getTableDescriptor(tableName);

            } catch (org.apache.hadoop.hbase.TableNotFoundException e) {

                tableExist = false;

                if (tableType == PTableType.VIEW) {

                    String fullTableName = Bytes.toString(tableName);

                    throw new ReadOnlyTableException(

                            "An HBase table for a VIEW must already exist",

                            SchemaUtil.getSchemaNameFromFullName(fullTableName),

                            SchemaUtil.getTableNameFromFullName(fullTableName));

                }

            }

            HTableDescriptor newDesc = generateTableDescriptor(tableName, existingDesc, tableType , props, families, splits);

           

            if (!tableExist) {

                /*

                 * Remove the splitPolicy attribute due to an HBase bug (see below)

                 */

                if (isMetaTable) {

                    newDesc.remove(HTableDescriptor.SPLIT_POLICY);

                }

                try {

                    if (splits == null) {

                        admin.createTable(newDesc);

                    } else {

                        admin.createTable(newDesc, splits);

                    }

                } catch (TableExistsException e) {

                    // We can ignore this, as it just means that another client beat us

                    // to creating the HBase metadata.

                    return false;

                }

                if (isMetaTable) {

                    checkClientServerCompatibility();

                    /*

                     * Now we modify the table to add the split policy, since we know that the client and

                     * server and compatible. This works around a nasty, known HBase bug where if a split

                     * policy class cannot be found on the server, the HBase table is left in a horrible

                     * "ghost" state where it can't be used and can't be deleted without bouncing the master.

                     */

                    newDesc.setValue(HTableDescriptor.SPLIT_POLICY, MetaDataSplitPolicy.class.getName());

                    admin.disableTable(tableName);

                    admin.modifyTable(tableName, newDesc);

                    admin.enableTable(tableName);

                }

                return true;

            } else {

                if (existingDesc.equals(newDesc)) {

                    // Table is already created. Note that the presplits are ignored in this case

                    if (isMetaTable) {

                        checkClientServerCompatibility();

                    }

                    return false;

                }

                boolean updateTo3_0 = false;

                if (isMetaTable) {

                    checkClientServerCompatibility();

                   

                    updateTo3_0 = existingDesc.getValue(SchemaUtil.UPGRADE_TO_3_0) == null;

                    if (updateTo3_0) {

                        // Check if SYSTEM.TABLE has multiple regions which is problematic, as

                        // we can't update it atomically. It's unlikely that this is the case

                        // but we'll find out if it is.

                        if (this.getAllTableRegions(tableName).size() > 1) {

                            throw new SQLException("Unable to convert SYSTEM.TABLE automatically as it is too big. Please contact customer support.");

                        }

                    }

                }

               

                // We'll do this alter at the end of the upgrade

                // Just let the table metadata be updated for 3.0 here, as otherwise

                // we have a potential race condition

                // Update metadata of table

                // TODO: Take advantage of online schema change ability by setting "hbase.online.schema.update.enable" to true

                admin.disableTable(tableName);

                // TODO: What if not all existing column families are present?

                admin.modifyTable(tableName, newDesc);

                admin.enableTable(tableName);

                return false;

            }

        } catch (IOException e) {

            sqlE = ServerUtil.parseServerException(e);

        } finally {

            try {

                if (admin != null) {

                    admin.close();

                }

            } catch (IOException e) {

                if (sqlE == null) {

                    sqlE = ServerUtil.parseServerException(e);

                } else {

                    sqlE.setNextException(ServerUtil.parseServerException(e));

                }

            } finally {

                if (sqlE != null) {

                    throw sqlE;

                }

            }

        }

        return true; // will never make it here

    }

    private static boolean isInvalidMutableIndexConfig(Long serverVersion) {

        if (serverVersion == null) {

            return false;

        }

        return !MetaDataUtil.decodeMutableIndexConfiguredProperly(serverVersion);

    }

   

    private static boolean isCompatible(Long serverVersion) {

        if (serverVersion == null) {

            return false;

        }

        return MetaDataUtil.areClientAndServerCompatible(serverVersion);

    }

    private void checkClientServerCompatibility() throws SQLException {

        StringBuilder buf = new StringBuilder("The following servers require an updated " + QueryConstants.DEFAULT_COPROCESS_PATH + " to be put in the classpath of HBase: ");

        boolean isIncompatible = false;

        int minHBaseVersion = Integer.MAX_VALUE;

        try {

            List<HRegionLocation> locations = this.getAllTableRegions(TYPE_TABLE_NAME_BYTES);

            Set<HRegionLocation> serverMap = Sets.newHashSetWithExpectedSize(locations.size());

            TreeMap<byte[], HRegionLocation> regionMap = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);

            List<byte[]> regionKeys = Lists.newArrayListWithExpectedSize(locations.size());

            for (HRegionLocation entry : locations) {

                if (!serverMap.contains(entry)) {

                    regionKeys.add(entry.getRegionInfo().getStartKey());

                    regionMap.put(entry.getRegionInfo().getRegionName(), entry);

                    serverMap.add(entry);

                }

            }

            final TreeMap<byte[],Long> results = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);

            connection.processExecs(MetaDataProtocol.class, regionKeys,

                    PhoenixDatabaseMetaData.TYPE_TABLE_NAME_BYTES, this.getDelegate().getExecutor(), new Batch.Call<MetaDataProtocol,Long>() {

                        @Override

                        public Long call(MetaDataProtocol instance) throws IOException {

                            return instance.getVersion();

                        }

                    },

                    new Batch.Callback<Long>(){

                        @Override

                        public void update(byte[] region, byte[] row, Long value) {

                          results.put(region, value);

                        }

                    });

            for (Map.Entry<byte[],Long> result : results.entrySet()) {

                // This is the "phoenix.jar" is in-place, but server is out-of-sync with client case.

                if (!isCompatible(result.getValue())) {

                    isIncompatible = true;

                    HRegionLocation name = regionMap.get(result.getKey());

                    buf.append(name);

                    buf.append(';');

                }

                hasInvalidIndexConfiguration |= isInvalidMutableIndexConfig(result.getValue());

                if (minHBaseVersion > MetaDataUtil.decodeHBaseVersion(result.getValue())) {

                    minHBaseVersion = MetaDataUtil.decodeHBaseVersion(result.getValue());

                }

            }

            lowestClusterHBaseVersion = minHBaseVersion;

        } catch (Throwable t) {

            // This is the case if the "phoenix.jar" is not on the classpath of HBase on the region server

            throw new SQLExceptionInfo.Builder(SQLExceptionCode.INCOMPATIBLE_CLIENT_SERVER_JAR).setRootCause(t)

                .setMessage("Ensure that " + QueryConstants.DEFAULT_COPROCESS_PATH + " is put on the classpath of HBase in every region server: " + t.getMessage())

                .build().buildException();

        }

        if (isIncompatible) {

            buf.setLength(buf.length()-1);

            throw new SQLExceptionInfo.Builder(SQLExceptionCode.OUTDATED_JARS).setMessage(buf.toString()).build().buildException();

        }

    }

    /**

     * Invoke meta data coprocessor with one retry if the key was found to not be in the regions

     * (due to a table split)

     */

    private MetaDataMutationResult metaDataCoprocessorExec(byte[] tableKey, Batch.Call<MetaDataProtocol, MetaDataMutationResult> callable) throws SQLException {

        try {

            boolean retried = false;

            while (true) {

                HRegionLocation regionLocation = retried ? connection.relocateRegion(PhoenixDatabaseMetaData.TYPE_TABLE_NAME_BYTES, tableKey) : connection.locateRegion(PhoenixDatabaseMetaData.TYPE_TABLE_NAME_BYTES, tableKey);

                List<byte[]> regionKeys = Collections.singletonList(regionLocation.getRegionInfo().getStartKey());

                final Map<byte[],MetaDataMutationResult> results = Maps.newHashMapWithExpectedSize(1);

                connection.processExecs(MetaDataProtocol.class, regionKeys,

                        PhoenixDatabaseMetaData.TYPE_TABLE_NAME_BYTES, this.getDelegate().getExecutor(), callable,

                        new Batch.Callback<MetaDataMutationResult>(){

                            @Override

                            public void update(byte[] region, byte[] row, MetaDataMutationResult value) {

                              results.put(region, value);

                            }

                        });

                assert(results.size() == 1);

                MetaDataMutationResult result = results.values().iterator().next();

                if (result.getMutationCode() == MutationCode.TABLE_NOT_IN_REGION) {

                    if (retried) return result;

                    retried = true;

                    continue;

                }

                return result;

            }

        } catch (IOException e) {

            throw ServerUtil.parseServerException(e);

        } catch (Throwable t) {

            throw new SQLException(t);

        }

    }

    @Override

    public MetaDataMutationResult createTable(final List<Mutation> tableMetaData, byte[] tableName, PTableType tableType,

            Map<String,Object> tableProps, final List<Pair<byte[],Map<String,Object>>> families, byte[][] splits) throws SQLException {

        byte[][] rowKeyMetadata = new byte[3][];

        Mutation m = tableMetaData.get(0);

        byte[] key = m.getRow();

        SchemaUtil.getVarChars(key, rowKeyMetadata);

        byte[] tenantIdBytes = rowKeyMetadata[PhoenixDatabaseMetaData.TENANT_ID_INDEX];

        byte[] schemaBytes = rowKeyMetadata[PhoenixDatabaseMetaData.SCHEMA_NAME_INDEX];

        byte[] tableBytes = rowKeyMetadata[PhoenixDatabaseMetaData.TABLE_NAME_INDEX];

        if (tableType != PTableType.VIEW || tableName != null) {

            tableName = tableName == null ? SchemaUtil.getTableNameAsBytes(schemaBytes, tableBytes) : tableName;

            ensureTableCreated(tableName, tableType, tableProps, families, splits);

        }

       

        byte[] tableKey = SchemaUtil.getTableKey(tenantIdBytes, schemaBytes, tableBytes);

        MetaDataMutationResult result = metaDataCoprocessorExec(tableKey,

            new Batch.Call<MetaDataProtocol, MetaDataMutationResult>() {

                @Override

                public MetaDataMutationResult call(MetaDataProtocol instance) throws IOException {

                  return instance.createTable(tableMetaData);

                }

            });

        return result;

    }

    @Override

    public MetaDataMutationResult getTable(byte[] tenantId, final byte[] schemaBytes, final byte[] tableBytes,

            final long tableTimestamp, final long clientTimestamp) throws SQLException {

        final byte[] nonNullTenantId = tenantId == null ? ByteUtil.EMPTY_BYTE_ARRAY : tenantId;

        byte[] tableKey = SchemaUtil.getTableKey(nonNullTenantId, schemaBytes, tableBytes);

        return metaDataCoprocessorExec(tableKey,

                new Batch.Call<MetaDataProtocol, MetaDataMutationResult>() {

                    @Override

                    public MetaDataMutationResult call(MetaDataProtocol instance) throws IOException {

                      return instance.getTable(nonNullTenantId, schemaBytes, tableBytes, tableTimestamp, clientTimestamp);

                    }

                });

    }

    @Override

    public MetaDataMutationResult dropTable(final List<Mutation> tableMetaData, final PTableType tableType) throws SQLException {

        byte[][] rowKeyMetadata = new byte[3][];

        SchemaUtil.getVarChars(tableMetaData.get(0).getRow(), rowKeyMetadata);

        byte[] tenantIdBytes = rowKeyMetadata[PhoenixDatabaseMetaData.TENANT_ID_INDEX];

        byte[] schemaBytes = rowKeyMetadata[PhoenixDatabaseMetaData.SCHEMA_NAME_INDEX];

        byte[] tableBytes = rowKeyMetadata[PhoenixDatabaseMetaData.TABLE_NAME_INDEX];

        byte[] tableKey = SchemaUtil.getTableKey(tenantIdBytes == null ? ByteUtil.EMPTY_BYTE_ARRAY : tenantIdBytes, schemaBytes, tableBytes);

        final MetaDataMutationResult result =  metaDataCoprocessorExec(tableKey,

                new Batch.Call<MetaDataProtocol, MetaDataMutationResult>() {

                    @Override

                    public MetaDataMutationResult call(MetaDataProtocol instance) throws IOException {

                      return instance.dropTable(tableMetaData, tableType.getSerializedValue());

                    }

                });

       

        final MutationCode code = result.getMutationCode();

        switch(code) {

        case TABLE_ALREADY_EXISTS:

            final ReadOnlyProps props = this.getProps();

            final boolean dropMetadata = props.getBoolean(DROP_METADATA_ATTRIB, DEFAULT_DROP_METADATA);

            if (dropMetadata) {

                dropTables(result.getTableNamesToDelete());

            }

            break;

        default:

            break;

        }

          return result;

    }

   

    private void dropTables(final List<byte[]> tableNamesToDelete) throws SQLException {

        HBaseAdmin admin = null;

        SQLException sqlE = null;

        try{

            admin = new HBaseAdmin(config);

            if (tableNamesToDelete != null){

                for ( byte[] tableName : tableNamesToDelete ) {

                    if ( admin.tableExists(tableName) ) {

                        admin.disableTable(tableName);

                        admin.deleteTable(tableName);

                    }

                }

            }

           

        } catch (IOException e) {

            sqlE = ServerUtil.parseServerException(e);

        } finally {

            try {

                if (admin != null) {

                    admin.close();

                }

            } catch (IOException e) {

                if (sqlE == null) {

                    sqlE = ServerUtil.parseServerException(e);

                } else {

                    sqlE.setNextException(ServerUtil.parseServerException(e));

                }

            } finally {

                if (sqlE != null) {

                    throw sqlE;

                }

            }

        }

    }

    @Override

    public MetaDataMutationResult addColumn(final List<Mutation> tableMetaData, PTableType tableType, List<Pair<byte[],Map<String,Object>>> families) throws SQLException {

        byte[][] rowKeyMetaData = new byte[3][];

        byte[] rowKey = tableMetaData.get(0).getRow();

        SchemaUtil.getVarChars(rowKey, rowKeyMetaData);

        byte[] tenantIdBytes = rowKeyMetaData[PhoenixDatabaseMetaData.TENANT_ID_INDEX];

        byte[] schemaBytes = rowKeyMetaData[PhoenixDatabaseMetaData.SCHEMA_NAME_INDEX];

        byte[] tableBytes = rowKeyMetaData[PhoenixDatabaseMetaData.TABLE_NAME_INDEX];

        byte[] tableKey = SchemaUtil.getTableKey(tenantIdBytes, schemaBytes, tableBytes);

        byte[] tableName = SchemaUtil.getTableNameAsBytes(schemaBytes, tableBytes);

        for ( Pair<byte[],Map<String,Object>>  family : families) {

           

            PTable table = latestMetaData.getTable(Bytes.toString(tableName));

            ensureFamilyCreated(table.getPhysicalName().getBytes(), tableType, family);

        }

        // Special case for call during drop table to ensure that the empty column family exists.

        // In this, case we only include the table header row, as until we add schemaBytes and tableBytes

        // as args to this function, we have no way of getting them in this case.

        // TODO: change to  if (tableMetaData.isEmpty()) once we pass through schemaBytes and tableBytes

        // Also, could be used to update property values on ALTER TABLE t SET prop=xxx

        if (tableMetaData.size() == 1 && tableMetaData.get(0).isEmpty()) {

            return null;

        }

        MetaDataMutationResult result =  metaDataCoprocessorExec(tableKey,

            new Batch.Call<MetaDataProtocol, MetaDataMutationResult>() {

                @Override

                public MetaDataMutationResult call(MetaDataProtocol instance) throws IOException {

                    return instance.addColumn(tableMetaData);

                }

            });

        return result;

    }

    @Override

    public MetaDataMutationResult dropColumn(final List<Mutation> tableMetaData, PTableType tableType) throws SQLException {

        byte[][] rowKeyMetadata = new byte[3][];

        SchemaUtil.getVarChars(tableMetaData.get(0).getRow(), rowKeyMetadata);

        byte[] tenantIdBytes = rowKeyMetadata[PhoenixDatabaseMetaData.TENANT_ID_INDEX];

        byte[] schemaBytes = rowKeyMetadata[PhoenixDatabaseMetaData.SCHEMA_NAME_INDEX];

        byte[] tableBytes = rowKeyMetadata[PhoenixDatabaseMetaData.TABLE_NAME_INDEX];

        byte[] tableKey = SchemaUtil.getTableKey(tenantIdBytes, schemaBytes, tableBytes);

        MetaDataMutationResult result = metaDataCoprocessorExec(tableKey,

            new Batch.Call<MetaDataProtocol, MetaDataMutationResult>() {

                @Override

                public MetaDataMutationResult call(MetaDataProtocol instance) throws IOException {

                    return instance.dropColumn(tableMetaData);

                }

            });

        final MutationCode code = result.getMutationCode();

        switch(code) {

        case TABLE_ALREADY_EXISTS:

            final ReadOnlyProps props = this.getProps();

            final boolean dropMetadata = props.getBoolean(DROP_METADATA_ATTRIB, DEFAULT_DROP_METADATA);

            if (dropMetadata) {

                dropTables(result.getTableNamesToDelete());

            }

            break;

        default:

            break;

        }

        return result;

      

    }

    // Keeping this to use for further upgrades

    protected PhoenixConnection addColumnsIfNotExists(PhoenixConnection oldMetaConnection, long timestamp, String columns) throws SQLException {

        Properties props = new Properties(oldMetaConnection.getClientInfo());

        props.setProperty(PhoenixRuntime.CURRENT_SCN_ATTRIB, Long.toString(timestamp));

        // Cannot go through DriverManager or you end up in an infinite loop because it'll call init again

        PhoenixConnection metaConnection = new PhoenixConnection(this, oldMetaConnection.getURL(), props, oldMetaConnection.getPMetaData());

        SQLException sqlE = null;

        try {

            metaConnection.createStatement().executeUpdate("ALTER TABLE " + PhoenixDatabaseMetaData.TYPE_SCHEMA_AND_TABLE + " ADD IF NOT EXISTS " + columns );

        } catch (SQLException e) {

            sqlE = e;

        } finally {

            try {

                oldMetaConnection.close();

            } catch (SQLException e) {

                if (sqlE != null) {

                    sqlE.setNextException(e);

                } else {

                    sqlE = e;

                }

            }

            if (sqlE != null) {

                throw sqlE;

            }

        }

        return metaConnection;

    }

   

    @Override

    public void init(String url, Properties props) throws SQLException {

        props = new Properties(props);

        props.setProperty(PhoenixRuntime.CURRENT_SCN_ATTRIB, Long.toString(MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP));

        PhoenixConnection metaConnection = new PhoenixConnection(this, url, props, PMetaDataImpl.EMPTY_META_DATA);

        SQLException sqlE = null;

        try {

            try {

                metaConnection.createStatement().executeUpdate(QueryConstants.CREATE_TABLE_METADATA);

            } catch (NewerTableAlreadyExistsException ignore) {

                // Ignore, as this will happen if the SYSTEM.TABLE already exists at this fixed timestamp.

                // A TableAlreadyExistsException is not thrown, since the table only exists *after* this fixed timestamp.

            }

            try {

                metaConnection.createStatement().executeUpdate(QueryConstants.CREATE_SEQUENCE_METADATA);

            } catch (NewerTableAlreadyExistsException ignore) {

                // Ignore, as this will happen if the SYSTEM.SEQUENCE already exists at this fixed timestamp.

                // A TableAlreadyExistsException is not thrown, since the table only exists *after* this fixed timestamp.

            }

        } catch (SQLException e) {

            sqlE = e;

        } finally {

            try {

                metaConnection.close();

            } catch (SQLException e) {

                if (sqlE != null) {

                    sqlE.setNextException(e);

                } else {

                    sqlE = e;

                }

            }

            if (sqlE != null) {

                throw sqlE;

            }

        }

    }

    @Override

    public MutationState updateData(MutationPlan plan) throws SQLException {

        return plan.execute();

    }

    @Override

    public int getLowestClusterHBaseVersion() {

        return lowestClusterHBaseVersion;

    }

    @Override

    public boolean hasInvalidIndexConfiguration() {

        return hasInvalidIndexConfiguration;

    }

    /**

     * Clears the Phoenix meta data cache on each region server

     * @throws SQLException

     */

    protected void clearCache() throws SQLException {

        try {

            SQLException sqlE = null;

            HTableInterface htable = this.getTable(PhoenixDatabaseMetaData.TYPE_TABLE_NAME_BYTES);

            try {

                htable.coprocessorExec(MetaDataProtocol.class, HConstants.EMPTY_START_ROW,

                        HConstants.EMPTY_END_ROW, new Batch.Call<MetaDataProtocol, Void>() {

                    @Override

                    public Void call(MetaDataProtocol instance) throws IOException {

                      instance.clearCache();

                      return null;

                    }

                  });

            } catch (IOException e) {

                throw ServerUtil.parseServerException(e);

            } catch (Throwable e) {

                sqlE = new SQLException(e);

            } finally {

                try {

                    htable.close();

                } catch (IOException e) {

                    if (sqlE == null) {

                        sqlE = ServerUtil.parseServerException(e);

                    } else {

                        sqlE.setNextException(ServerUtil.parseServerException(e));

                    }

                } finally {

                    if (sqlE != null) {

                        throw sqlE;

                    }

                }

            }

        } catch (Exception e) {

            throw new SQLException(ServerUtil.parseServerException(e));

        }

    }

    @Override

    public HBaseAdmin getAdmin() throws SQLException {

        try {

            return new HBaseAdmin(config);

        } catch (IOException e) {

            throw new PhoenixIOException(e);

        }

    }

    @Override

    public MetaDataMutationResult updateIndexState(final List<Mutation> tableMetaData, String parentTableName) throws SQLException {

        byte[][] rowKeyMetadata = new byte[3][];

        SchemaUtil.getVarChars(tableMetaData.get(0).getRow(), rowKeyMetadata);

        byte[] tableKey = SchemaUtil.getTableKey(ByteUtil.EMPTY_BYTE_ARRAY, rowKeyMetadata[PhoenixDatabaseMetaData.SCHEMA_NAME_INDEX], rowKeyMetadata[PhoenixDatabaseMetaData.TABLE_NAME_INDEX]);

        return metaDataCoprocessorExec(tableKey,

                new Batch.Call<MetaDataProtocol, MetaDataMutationResult>() {

                    @Override

                    public MetaDataMutationResult call(MetaDataProtocol instance) throws IOException {

                      return instance.updateIndexState(tableMetaData);

                    }

                });

    }

    @Override

    public long createSequence(String tenantId, String schemaName, String sequenceName, long startWith, long incrementBy, int cacheSize, long timestamp)

            throws SQLException {

        SequenceKey sequenceKey = new SequenceKey(tenantId, schemaName, sequenceName);

        Sequence newSequences = new Sequence(sequenceKey);

        Sequence sequence = sequenceMap.putIfAbsent(sequenceKey, newSequences);

        if (sequence == null) {

            sequence = newSequences;

        }

        try {

            sequence.getLock().lock();

            // Now that we have the lock we need, create the sequence

            Append append = sequence.createSequence(startWith, incrementBy, cacheSize, timestamp);

            HTableInterface htable = this.getTable(PhoenixDatabaseMetaData.SEQUENCE_TABLE_NAME_BYTES);

            try {

                Result result = htable.append(append);

                return sequence.createSequence(result);

            } catch (IOException e) {

                throw ServerUtil.parseServerException(e);

            }

        } finally {

            sequence.getLock().unlock();

        }

    }

    @Override

    public long dropSequence(String tenantId, String schemaName, String sequenceName, long timestamp) throws SQLException {

        SequenceKey sequenceKey = new SequenceKey(tenantId, schemaName, sequenceName);

        Sequence newSequences = new Sequence(sequenceKey);

        Sequence sequence = sequenceMap.putIfAbsent(sequenceKey, newSequences);

        if (sequence == null) {

            sequence = newSequences;

        }

        try {

            sequence.getLock().lock();

            // Now that we have the lock we need, create the sequence

            Append append = sequence.dropSequence(timestamp);

            HTableInterface htable = this.getTable(PhoenixDatabaseMetaData.SEQUENCE_TABLE_NAME_BYTES);

            try {

                Result result = htable.append(append);

                return sequence.dropSequence(result);

            } catch (IOException e) {

                throw ServerUtil.parseServerException(e);

            }

        } finally {

            sequence.getLock().unlock();

        }

    }

    /**

     * Gets the current sequence value

     * @param tenantId

     * @param sequence

     * @return

     * @throws SQLException if cached sequence cannot be found

     */

    @Override

    public long getSequenceValue(SequenceKey sequenceKey, long timestamp) throws SQLException {

        Sequence sequence = sequenceMap.get(sequenceKey);

        if (sequence == null) {

            throw new SQLExceptionInfo.Builder(SQLExceptionCode.CANNOT_CALL_CURRENT_BEFORE_NEXT_VALUE)