/**
* Copyright (C) 2014 Stratio (http://stratio.com)
*
* Licensed 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 com.stratio.ingestion.sink.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import org.apache.flume.Channel;
import org.apache.flume.Context;
import org.apache.flume.CounterGroup;
import org.apache.flume.Event;
import org.apache.flume.EventDeliveryException;
import org.apache.flume.Transaction;
import org.apache.flume.conf.Configurable;
import org.apache.flume.instrumentation.SinkCounter;
import org.apache.flume.sink.AbstractSink;
import org.jooq.ConnectionProvider;
import org.jooq.DSLContext;
import org.jooq.SQLDialect;
import org.jooq.impl.DSL;
import org.jooq.impl.DefaultConnectionProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Strings;
/**
* Saves Flume events to any database with a JDBC driver. It can operate either
* with automatic headers-to-tables mapping or with custom SQL queries.
*
* Available configuration parameters are:
*
* <p><ul>
* <li><tt>driver</tt> <em>(string, required)</em>: The driver class (e.g.
* <tt>org.h2.Driver</tt>, <tt>org.postgresql.Driver</tt>). <strong>NOTE:</strong>
* Stratio JDBC Sink does not include any JDBC driver. You must add a JDBC
* driver to your Flume classpath.</li>
* <li><tt>connectionString</tt> <em>(string, required)</em>: A valid
* connection string to a database. Check the documentation for your JDBC driver
* for more information.</li>
* <li><tt>username</tt> <em>(string)</em>: A valid database username.</li>
* <li><tt>password</tt> <em>(string)</em>: Password.</li>
* <li><tt>sqlDialect</tt> <em>(string, required)</em>: The SQL dialect of your
* database. This should be one of the following: <tt>CUBRID</tt>, <tt>DERBY</tt>,
* <tt>FIREBIRD</tt>, <tt>H2</tt>, <tt>HSQLDB</tt>, <tt>MARIADB</tt>, <tt>MYSQL</tt>,
* <tt>POSTGRES</tt>, <tt>SQLITE</tt>.</li>
* <li><tt>table</tt> <em>(string)</em>: A table to store your events.
* <em>This is only used for automatic mapping.</em></li>
* <li><tt>sql</tt> <em>(string)</em>: A custom SQL query to use. If specified,
* this query will be used instead of automatic mapping. E.g.
* <tt>INSERT INTO tweets (text, num_hashtags, timestamp) VALUES (${body:string}, ${header.numberOfHashtags:integer}, ${header.date:timestamp})</tt>.
* Note the variable format: the first part is either <tt>body</tt> or
* <tt>header.yourHeaderName</tt> and then the SQL type.</li>
* <li><tt>batchSize</tt> <em>(integer)</em>: Number of events that will be grouped
* in the same query and transaction. Defaults to <tt>20</tt>.</li>
* </ul></p>
*
*/
public class JDBCSink extends AbstractSink implements Configurable {
private static final Logger log = LoggerFactory.getLogger(JDBCSink.class);
private static final int DEFAULT_BATCH_SIZE = 20;
private static final String CONF_DRIVER = "driver";
private static final String CONF_CONNECTION_STRING = "connectionString";
private static final String CONF_SQL_DIALECT = "sqlDialect";
private static final String CONF_TABLE = "table";
private static final String CONF_BATCH_SIZE = "batchSize";
private static final String CONF_SQL = "sql";
private static final String CONF_USER = "username";
private static final String CONF_PASSWORD = "password";
private Connection connection;
private DSLContext create;
private SinkCounter sinkCounter;
private int batchSize;
private QueryGenerator queryGenerator;
private final CounterGroup counterGroup = new CounterGroup();
public JDBCSink() {
super();
}
@Override
public void configure(Context context) {
final String driver = context.getString(CONF_DRIVER);
final String connectionString = context.getString(CONF_CONNECTION_STRING);
this.batchSize = context.getInteger(CONF_BATCH_SIZE, DEFAULT_BATCH_SIZE);
try {
Class.forName(driver).newInstance();
} catch (ClassNotFoundException ex) {
throw new JDBCSinkException(ex);
} catch (InstantiationException ex) {
throw new JDBCSinkException(ex);
} catch (IllegalAccessException ex) {
throw new JDBCSinkException(ex);
}
String username = context.getString(CONF_USER);
String password = context.getString(CONF_PASSWORD);
connection = null;
try {
if(Strings.isNullOrEmpty(username) || Strings.isNullOrEmpty(password)){ //Non authorized
connection = DriverManager.getConnection(connectionString);
} else { //Authorized
//TODO: check all possible connections to remove this if
if (CONF_SQL_DIALECT.equals("H2")) {
connection = DriverManager.getConnection(connectionString+";USER="+username+";PASSWORD="+password);
} else {
connection = DriverManager.getConnection(connectionString, username, password);
}
}
} catch (SQLException ex) {
throw new JDBCSinkException(ex);
}
try {
connection.setAutoCommit(false);
} catch (SQLException ex) {
throw new JDBCSinkException(ex);
}
final ConnectionProvider connectionProvider = new DefaultConnectionProvider(connection);
final SQLDialect sqlDialect = SQLDialect.valueOf(context.getString(CONF_SQL_DIALECT).toUpperCase(Locale.ENGLISH));
create = DSL.using(connectionProvider, sqlDialect);
final String sql = context.getString(CONF_SQL);
if (sql == null) {
this.queryGenerator = new MappingQueryGenerator(create, context.getString(CONF_TABLE));
} else {
this.queryGenerator = new TemplateQueryGenerator(sqlDialect, sql);
}
this.sinkCounter = new SinkCounter(this.getName());
}
@Override
public Status process() throws EventDeliveryException {
log.debug("Executing JDBCSink.process()...");
Status status = Status.READY;
Channel channel = getChannel();
Transaction txn = channel.getTransaction();
try {
txn.begin();
int count;
List<Event> eventList= new ArrayList<Event>();
for (count = 0; count < batchSize; ++count) {
Event event = channel.take();
if (event == null) {
break;
}
eventList.add(event);
}
if (count <= 0) {
sinkCounter.incrementBatchEmptyCount();
counterGroup.incrementAndGet("channel.underflow");
status = Status.BACKOFF;
} else {
if (count < batchSize) {
sinkCounter.incrementBatchUnderflowCount();
status = Status.BACKOFF;
} else {
sinkCounter.incrementBatchCompleteCount();
}
final boolean success = this.queryGenerator.executeQuery(create, eventList);
if (!success) {
throw new JDBCSinkException("Query failed");
}
connection.commit();
sinkCounter.addToEventDrainAttemptCount(count);
}
txn.commit();
sinkCounter.addToEventDrainSuccessCount(count);
counterGroup.incrementAndGet("transaction.success");
} catch (Throwable t) {
log.error("Exception during process", t);
try {
connection.rollback();
} catch (SQLException ex) {
log.error("Exception on rollback", ex);
} finally {
txn.rollback();
status = Status.BACKOFF;
this.sinkCounter.incrementConnectionFailedCount();
if (t instanceof Error) {
throw new JDBCSinkException(t);
}
}
} finally {
txn.close();
}
return status;
}
public Status BACKUP_process() throws EventDeliveryException {
Status status = Status.BACKOFF;
Transaction transaction = this.getChannel().getTransaction();
try {
transaction.begin();
List<Event> eventList = this.takeEventsFromChannel(
this.getChannel(), this.batchSize);
status = Status.READY;
if (!eventList.isEmpty()) {
if (eventList.size() == this.batchSize) {
this.sinkCounter.incrementBatchCompleteCount();
} else {
this.sinkCounter.incrementBatchUnderflowCount();
}
final boolean success = this.queryGenerator.executeQuery(create, eventList);
if (!success) {
throw new JDBCSinkException("Query failed");
}
connection.commit();
this.sinkCounter.addToEventDrainSuccessCount(eventList.size());
} else {
this.sinkCounter.incrementBatchEmptyCount();
}
transaction.commit();
status = Status.READY;
} catch (Throwable t) {
log.error("Exception during process", t);
try {
connection.rollback();
} catch (SQLException ex) {
log.error("Exception on rollback", ex);
} finally {
transaction.rollback();
status = Status.BACKOFF;
this.sinkCounter.incrementConnectionFailedCount();
if (t instanceof Error) {
throw new JDBCSinkException(t);
}
}
} finally {
transaction.close();
}
return status;
}
@Override
public synchronized void start() {
this.sinkCounter.start();
super.start();
}
@Override
public synchronized void stop() {
this.sinkCounter.stop();
super.stop();
}
private List<Event> takeEventsFromChannel(Channel channel, int eventsToTake) {
List<Event> events = new ArrayList<Event>();
for (int i = 0; i < eventsToTake; i++) {
this.sinkCounter.incrementEventDrainAttemptCount();
events.add(channel.take());
}
events.removeAll(Collections.singleton(null));
return events;
}
}