/*
* ProActive Parallel Suite(TM):
* The Open Source library for parallel and distributed
* Workflows & Scheduling, Orchestration, Cloud Automation
* and Big Data Analysis on Enterprise Grids & Clouds.
*
* Copyright (c) 2007 - 2017 ActiveEon
* Contact: contact@activeeon.com
*
* This library is free software: you can redistribute it and/or
* modify it under the terms of the GNU Affero General Public License
* as published by the Free Software Foundation: version 3 of
* the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* If needed, contact us to obtain a release under GPL Version 2 or 3
* or a different license than the AGPL.
*/
package org.ow2.proactive.db;
import org.apache.log4j.Logger;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.exception.LockAcquisitionException;
import org.objectweb.proactive.utils.Sleeper;
import org.ow2.proactive.scheduler.core.properties.PASchedulerProperties;
public class TransactionHelper {
private static final Logger logger = Logger.getLogger(TransactionHelper.class);
private final SessionFactory sessionFactory;
public TransactionHelper(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
/**
* Execute the specified {@code sessionWork} in a session configured
* for read-only interactions with the database. This method should be
* used for select queries.
* <p>
* In case of a transaction failure a retry is performed or not based on
* the value defined by {@code PASchedulerProperties.SCHEDULER_DB_TRANSACTION_MAXIMUM_RETRIES}.
*
* @param sessionWork the action to perform.
* @param <T> the result type of the session work.
* @return session work result based on the generic type.
*/
public <T> T executeReadOnlyTransaction(SessionWork<T> sessionWork) {
return tryExecuteTransactionLoop(sessionWork, false, true);
}
/**
* Execute the specified {@code sessionWork} in a session configured
* for read/write interactions with the database. This method should be
* used for insert, update, and delete queries. If select only is required,
* then {@link #executeReadOnlyTransaction(SessionWork)} could be used.
* <p>
* In case of database error while executing the query, a rollback is
* performed and a retry executed depending of the value associated to
* the property {@code PASchedulerProperties.SCHEDULER_DB_TRANSACTION_MAXIMUM_RETRIES}.
*
* @param sessionWork the action to perform.
* @param <T> the result type of the session work.
* @return session work result based on the generic type.
*/
public <T> T executeReadWriteTransaction(SessionWork<T> sessionWork) {
return tryExecuteTransactionLoop(sessionWork, true, true);
}
public <T> T executeReadWriteTransaction(SessionWork<T> sessionWork, boolean readOnlyEntities) {
return tryExecuteTransactionLoop(sessionWork, true, readOnlyEntities);
}
private <T> T tryExecuteTransactionLoop(SessionWork<T> sessionWork, boolean readWriteTransaction,
boolean readOnlyEntities) {
Throwable lastException = null;
int dampingFactor = PASchedulerProperties.SCHEDULER_DB_TRANSACTION_DAMPING_FACTOR.getValueAsInt();
int delay = PASchedulerProperties.SCHEDULER_DB_TRANSACTION_SLEEP_DELAY.getValueAsInt();
int maximumNumberOfRetries = Math.max(PASchedulerProperties.SCHEDULER_DB_TRANSACTION_MAXIMUM_RETRIES.getValueAsInt(),
0);
for (int i = 0; i <= maximumNumberOfRetries; i++) {
try {
return tryExecuteTransaction(sessionWork, readWriteTransaction, readOnlyEntities);
} catch (Throwable exception) {
lastException = exception;
logger.warn(String.format("Database operation failed. Automatic retry in %d ms (attempt %d)", delay, i),
exception);
new Sleeper(delay, logger).sleep();
delay *= dampingFactor;
}
}
logger.warn("Maximum number of transaction retries exceeded, giving up. Last exception is: ", lastException);
throw new DatabaseManagerException(lastException);
}
private <T> T tryExecuteTransaction(SessionWork<T> sessionWork, boolean readWriteTransaction,
boolean readOnlyEntities) {
Session session = sessionFactory.openSession();
session.setDefaultReadOnly(readOnlyEntities);
try {
session.beginTransaction();
T result = sessionWork.doInTransaction(session);
session.getTransaction().commit();
return result;
} catch (Throwable e) {
logger.warn("Database operation failed", e);
if (readWriteTransaction) {
try {
session.getTransaction().rollback();
} catch (Throwable rollbackError) {
logger.warn("Failed to rollback transaction", rollbackError);
}
}
throw e;
} finally {
try {
session.close();
} catch (HibernateException e) {
logger.warn("Failed to close session", e);
}
}
}
}