Java tutorial
/** * SAHARA Scheduling Server * * Schedules and assigns local laboratory rigs. * * @license See LICENSE in the top level directory for complete license terms. * * Copyright (c) 2010, University of Technology, Sydney * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the University of Technology, Sydney nor the names * of its contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * @author Michael Diponio (mdiponio) * @date 8th April 2010 */ package au.edu.uts.eng.remotelabs.schedserver.session.impl; import java.util.Date; import java.util.List; import org.hibernate.Criteria; import org.hibernate.HibernateException; import org.hibernate.criterion.Projections; import org.hibernate.criterion.Restrictions; import au.edu.uts.eng.remotelabs.schedserver.bookings.BookingEngineService; import au.edu.uts.eng.remotelabs.schedserver.dataaccess.DataAccessActivator; import au.edu.uts.eng.remotelabs.schedserver.dataaccess.entities.Bookings; import au.edu.uts.eng.remotelabs.schedserver.dataaccess.entities.ResourcePermission; import au.edu.uts.eng.remotelabs.schedserver.dataaccess.entities.Session; import au.edu.uts.eng.remotelabs.schedserver.logger.Logger; import au.edu.uts.eng.remotelabs.schedserver.logger.LoggerActivator; import au.edu.uts.eng.remotelabs.schedserver.queuer.QueueInfo; import au.edu.uts.eng.remotelabs.schedserver.rigoperations.RigNotifier; import au.edu.uts.eng.remotelabs.schedserver.rigoperations.RigReleaser; import au.edu.uts.eng.remotelabs.schedserver.session.SessionActivator; /** * Either expires or extends the time of all sessions which are close to * the session duration duration. */ public class SessionExpiryChecker implements Runnable { /** Minimum extension duration. */ public static final int TIME_EXT = 300; /** Logger. */ private Logger logger; /** Flag to specify if this is a test run. */ private boolean notTest = true; public SessionExpiryChecker() { this.logger = LoggerActivator.getLogger(); } @SuppressWarnings("unchecked") @Override public void run() { org.hibernate.Session db = null; try { if ((db = DataAccessActivator.getNewSession()) == null) { this.logger.warn("Unable to obtain a database session, for rig session status checker. Ensure the " + "SchedulingServer-DataAccess bundle is installed and active."); return; } boolean kicked = false; Criteria query = db.createCriteria(Session.class); query.add(Restrictions.eq("active", Boolean.TRUE)).add(Restrictions.isNotNull("assignmentTime")); Date now = new Date(); List<Session> sessions = query.list(); for (Session ses : sessions) { ResourcePermission perm = ses.getResourcePermission(); int remaining = ses.getDuration() + // The session time (perm.getAllowedExtensions() - ses.getExtensions()) * perm.getExtensionDuration() - // Extension time Math.round((System.currentTimeMillis() - ses.getAssignmentTime().getTime()) / 1000); // In session time int extension = perm.getSessionDuration() - ses.getDuration() >= TIME_EXT ? TIME_EXT : perm.getExtensionDuration(); /****************************************************************** * For sessions that have been marked for termination, terminate * * those that have no more remaining time. * ******************************************************************/ if (ses.isInGrace()) { if (remaining <= 0) { ses.setActive(false); ses.setRemovalTime(now); db.beginTransaction(); db.flush(); db.getTransaction().commit(); this.logger.info("Terminating session for " + ses.getUserNamespace() + ':' + ses.getUserName() + " on " + ses.getAssignedRigName() + " because it is expired and the grace period has elapsed."); if (this.notTest) new RigReleaser().release(ses, db); } } /****************************************************************** * For sessions with remaining time less than the grace duration: * * 1) If the session has no remaining extensions, mark it for * * termination. * * 2) Else, if the session rig is queued, mark it for * * termination. * * 3) Else, extend the sessions time. * ******************************************************************/ else if (remaining < ses.getRig().getRigType().getLogoffGraceDuration()) { BookingEngineService service; /* Need to make a decision whether to extend time or set for termination. */ if (ses.getExtensions() <= 0 && ses.getDuration() >= perm.getSessionDuration()) { this.logger.info("Session for " + ses.getUserNamespace() + ':' + ses.getUserName() + " on " + "rig " + ses.getAssignedRigName() + " is expired and cannot be extended. Marking " + "session for expiry and giving a grace period."); ses.setInGrace(true); ses.setRemovalReason("No more session time extensions."); db.beginTransaction(); db.flush(); db.getTransaction().commit(); /* Notification warning. */ if (this.notTest) new RigNotifier().notify("Your session will expire in " + remaining + " seconds. " + "Please finish and exit.", ses, db); } else if ((Integer) db.createCriteria(Bookings.class) .add(Restrictions.eq("active", Boolean.TRUE)) .add(Restrictions.eq("user", ses.getUser())).add(Restrictions.ge("startTime", now)) .add(Restrictions.lt("startTime", new Date(System.currentTimeMillis() + extension * 1000))) .setProjection(Projections.rowCount()).uniqueResult() > 0) { this.logger.info("Session for " + ses.getUserNamespace() + ':' + ses.getUserName() + " on " + "rig" + ses.getAssignedRigName() + " is being terminated because the user has a " + "starting booking. Marking session for expiry and giving a grace period."); ses.setInGrace(true); ses.setRemovalReason("User has starting booking."); db.beginTransaction(); db.flush(); db.getTransaction().commit(); /* Notification warning. */ if (this.notTest) new RigNotifier().notify("Your session will expire in " + remaining + " seconds. " + "Please finish and exit. Please note, you have a reservation that starts after this" + " session so do not leave.", ses, db); } else if (QueueInfo.isQueued(ses.getRig(), db) || ((service = SessionActivator.getBookingService()) != null && !service.extendQueuedSession(ses.getRig(), ses, extension, db))) { this.logger.info( "Session for " + ses.getUserNamespace() + ':' + ses.getUserName() + " on " + "rig " + ses.getAssignedRigName() + " is expired and the rig is queued or booked. " + "Marking session for expiry and giving a grace period."); ses.setInGrace(true); ses.setRemovalReason("Rig is queued or booked."); db.beginTransaction(); db.flush(); db.getTransaction().commit(); /* Notification warning. */ if (this.notTest) new RigNotifier().notify("Your session will end in " + remaining + " seconds. " + "After this you be removed, so please logoff.", ses, db); } else { this.logger.info("Session for " + ses.getUserNamespace() + ':' + ses.getUserName() + " on " + "rig " + ses.getAssignedRigName() + " is expired and is having its session time " + "extended by " + extension + " seconds."); if (perm.getSessionDuration() - ses.getDuration() >= TIME_EXT) { ses.setDuration(ses.getDuration() + extension); } else { ses.setExtensions((short) (ses.getExtensions() - 1)); } db.beginTransaction(); db.flush(); db.getTransaction().commit(); } } /****************************************************************** * For sessions created with a user class that can be kicked off, * * if the rig is queued, the user is kicked off immediately. * ******************************************************************/ /* DODGY The 'kicked' flag is to only allow a single kick per * pass. This is allow time for the rig to be released and take the * queued session. This is a hack at best, but should be addressed * by a released - cleaning up meta state. */ else if (!kicked && QueueInfo.isQueued(ses.getRig(), db) && perm.getUserClass().isKickable()) { kicked = true; /* No grace is being given. */ this.logger .info("A kickable user is using a rig that is queued for, so they are being removed."); ses.setActive(false); ses.setRemovalTime(now); ses.setRemovalReason("Resource was queued and user was kickable."); db.beginTransaction(); db.flush(); db.getTransaction().commit(); if (this.notTest) new RigReleaser().release(ses, db); } /****************************************************************** * Finally, for sessions with time still remaining, check * * session activity timeout - if it is not ignored and is ready * * for use. * ******************************************************************/ else if (ses.isReady() && ses.getResourcePermission().isActivityDetected() && (System.currentTimeMillis() - ses.getActivityLastUpdated().getTime()) / 1000 > perm .getSessionActivityTimeout()) { /* Check activity. */ if (this.notTest) new SessionIdleKicker().kickIfIdle(ses, db); } } } catch (HibernateException hex) { this.logger.error("Failed to query database to expired sessions (Exception: " + hex.getClass().getName() + ", Message:" + hex.getMessage() + ")."); if (db != null && db.getTransaction() != null) { try { db.getTransaction().rollback(); } catch (HibernateException ex) { this.logger.error("Exception rolling back session expiry transaction (Exception: " + ex.getClass().getName() + "," + " Message: " + ex.getMessage() + ")."); } } } catch (Throwable thr) { this.logger.error("Caught unchecked exception in session expirty checker. Exception: " + thr.getClass() + ", message: " + thr.getMessage() + '.'); } finally { try { if (db != null) db.close(); } catch (HibernateException ex) { this.logger.error("Exception cleaning up database session (Exception: " + ex.getClass().getName() + "," + " Message: " + ex.getMessage() + ")."); } } } }