| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.sqoop.mapreduce; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.mapreduce.JobContext; |
| import org.apache.hadoop.mapreduce.OutputCommitter; |
| import org.apache.hadoop.mapreduce.OutputFormat; |
| import org.apache.hadoop.mapreduce.RecordWriter; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.sqoop.mapreduce.db.DBConfiguration; |
| import org.apache.sqoop.lib.SqoopRecord; |
| |
| /** |
| * Insert the emitted keys as records into a database table. |
| * Insert failures are handled by the registered Failure Handler class which |
| * allows for recovering from certain failures like intermittent connection |
| * or database throttling, .. etc |
| * |
| * The number of records per transaction is governed by the |
| * sqoop.export.records.per.statement configuration value or else default |
| * value is used |
| * |
| * Record objects are buffered before actually performing the INSERT |
| * statements; this requires that the key implement the |
| * SqoopRecord interface. |
| */ |
| public class SQLServerResilientExportOutputFormat<K extends SqoopRecord, V> |
| extends OutputFormat<K, V> { |
| |
| private static final Log LOG = LogFactory.getLog( |
| SQLServerResilientExportOutputFormat.class); |
| |
| public static final String EXPORT_FAILURE_HANDLER_CLASS = |
| "sqoop.export.failure.handler.class"; |
| |
| public static final int DEFAULT_RECORDS_PER_STATEMENT = 1000; |
| |
| private int curListIdx = 0; |
| |
| @Override |
| /** {@inheritDoc} */ |
| public void checkOutputSpecs(JobContext context) |
| throws IOException, InterruptedException { |
| Configuration conf = context.getConfiguration(); |
| DBConfiguration dbConf = new DBConfiguration(conf); |
| |
| // Sanity check all the configuration values we need. |
| if (null == conf.get(DBConfiguration.URL_PROPERTY)) { |
| throw new IOException("Database connection URL is not set."); |
| } else if (null == dbConf.getOutputTableName()) { |
| throw new IOException("Table name is not set for export"); |
| } else if (null == dbConf.getOutputFieldNames() |
| && 0 == dbConf.getOutputFieldCount()) { |
| throw new IOException( |
| "Output field names are null and zero output field count set."); |
| } |
| } |
| |
| @Override |
| /** {@inheritDoc} */ |
| public RecordWriter<K, V> getRecordWriter(TaskAttemptContext context) |
| throws IOException { |
| try { |
| return new SQLServerExportRecordWriter<K, V>(context); |
| } catch (Exception e) { |
| throw new IOException(e); |
| } |
| } |
| |
| @Override |
| /** {@inheritDoc} */ |
| public OutputCommitter getOutputCommitter(TaskAttemptContext context) |
| throws IOException, InterruptedException { |
| return new NullOutputCommitter(); |
| } |
| |
| /** |
| * RecordWriter to write the output to a row in a database table. |
| * The actual database updates are executed in a parallel thread in a |
| * resilient fashion which attempts to recover failed operations |
| */ |
| public class SQLServerExportRecordWriter<K extends SqoopRecord, V> |
| extends RecordWriter<K, V> { |
| |
| private final Log LOG = LogFactory.getLog( |
| SQLServerExportRecordWriter.class); |
| private final int LIST_COUNT = 2; |
| protected Configuration conf; |
| protected SQLServerAsyncDBExecThread execThread; |
| |
| // Number of records to buffer before sending as a batch |
| protected int recordsPerStmt; |
| |
| // We alternate between 2 lists of records as we go, as one is sent to the |
| // target database the other gets asynchronously filled |
| protected List<List<SqoopRecord>> recordsLists = new ArrayList<List<SqoopRecord>>(); |
| protected List<SqoopRecord> currentList; |
| public SQLServerExportRecordWriter(TaskAttemptContext context) |
| throws IOException { |
| conf = context.getConfiguration(); |
| |
| recordsPerStmt = conf.getInt( |
| AsyncSqlOutputFormat.RECORDS_PER_STATEMENT_KEY, |
| DEFAULT_RECORDS_PER_STATEMENT); |
| |
| // Create the lists to host incoming records |
| List<SqoopRecord> newList; |
| for (int i = 0; i < LIST_COUNT; ++i) { |
| newList = new ArrayList<SqoopRecord>(recordsPerStmt); |
| recordsLists.add(newList); |
| } |
| currentList = recordsLists.get(0); |
| // Initialize the DB exec Thread |
| initializeExecThread(); |
| |
| // Start the DB exec thread |
| execThread.start(); |
| } |
| |
| /** |
| * Initialize the thread used to perform the asynchronous DB operation |
| */ |
| protected void initializeExecThread() throws IOException { |
| execThread = new SQLServerExportDBExecThread(); |
| execThread.initialize(conf); |
| } |
| |
| @Override |
| /** {@inheritDoc} */ |
| public void write(K key, V value) |
| throws InterruptedException, IOException { |
| try { |
| currentList.add((SqoopRecord) key.clone()); |
| if (currentList.size() >= this.recordsPerStmt) { |
| // Schedule the current list for asynchronous transfer |
| // This will block if the previous operation is still in progress |
| execThread.put(currentList); |
| |
| // Switch to the other list for receiving incoming records |
| curListIdx = (curListIdx + 1) % recordsLists.size(); |
| |
| // Clear the list to be used in case it has previous records |
| currentList = recordsLists.get(curListIdx); |
| currentList.clear(); |
| } |
| } catch (CloneNotSupportedException cnse) { |
| throw new IOException("Could not buffer record", cnse); |
| } |
| } |
| |
| @Override |
| public void close(TaskAttemptContext context) throws IOException, |
| InterruptedException { |
| try { |
| // Ensure we flush the list of records to the database |
| if (currentList.size() > 0) { |
| execThread.put(currentList); |
| } |
| } |
| finally { |
| execThread.close(); |
| execThread.join(); |
| } |
| |
| // Final check for any exceptions raised when writing to the database |
| Exception lastException = execThread.getLastError(); |
| if (lastException != null) { |
| LOG.error("Asynchronous writer thread encountered the following " + |
| "exception: " + lastException.toString()); |
| throw new IOException(lastException); |
| } |
| } |
| } |
| } |