Question

I am using quartz and nhibernate and ran into a problem. Normally I have all my nhibernate sessions close on finish of a web request but I have a scheduler that starts on application start and I need to pass in a nhibernate session that I think should never be closed.

I am unsure how to do that.

Ninject

 public class NhibernateSessionFactoryProvider : Provider<ISessionFactory>
    {   
        protected override ISessionFactory CreateInstance(IContext context)
        {
            var sessionFactory = new NhibernateSessionFactory();
            return sessionFactory.GetSessionFactory();
        }
    }

  public class NhibernateModule : NinjectModule
    {
        public override void Load()
        {
            Bind<ISessionFactory>().ToProvider<NhibernateSessionFactoryProvider>().InSingletonScope();
            Bind<ISession>().ToMethod(context => context.Kernel.Get<ISessionFactory>().OpenSession()).InRequestScope();
        }
    }

Global.aspx

  protected void Application_Start()
    {
        // Hook our DI stuff when application starts
        IKernel kernel = SetupDependencyInjection();

        // get the reminder service HERE IS WHERE THE PROBLEMS START
        IScheduledRemindersService scheduledRemindersService = kernel.Get<IScheduledRemindersService>();

        scheduledRemindersService.StartTaskRemindersSchedule();

        RegisterMaps.Register();

        AreaRegistration.RegisterAllAreas();

        RegisterGlobalFilters(GlobalFilters.Filters);
        RegisterRoutes(RouteTable.Routes);


    }


    public IKernel SetupDependencyInjection()
    {
        IKernel kernel = CreateKernel();
        // Tell ASP.NET MVC 3 to use our Ninject DI Container
        DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));

        return kernel;
    }

    protected IKernel CreateKernel()
    {
        var modules = new INinjectModule[]
                          {
                             new NhibernateModule(),
                             new ServiceModule(),
                             new RepoModule()
                          };

        return new StandardKernel(modules);
    }

// service that is causing me the problems. Ninject will bind reminderRepo and give it an nihbernate session.

private readonly IReminderRepo reminderRepo;
private readonly ISchedulerFactory schedulerFactory;

public ScheduledRemindersService(IReminderRepo reminderRepo)
{
    this.reminderRepo = reminderRepo;
    schedulerFactory = new StdSchedulerFactory();
}

public void StartTaskRemindersSchedule()
{

    IScheduler scheduler = schedulerFactory.GetScheduler();

    scheduler.Start();

    JobDetail jobDetail = new JobDetail("TaskRemindersJob",null,typeof(TaskReminderJob));
    jobDetail.JobDataMap["reminderRepo"] = reminderRepo;

    DateTime evenMinuteDate = TriggerUtils.GetEvenMinuteDate(DateTime.UtcNow);


    SimpleTrigger trigger = new SimpleTrigger("TaskRemindersTrigger", null,
                        DateTime.UtcNow,
                        null,
                        SimpleTrigger.RepeatIndefinitely,
                        TimeSpan.FromMinutes(1));

    scheduler.ScheduleJob(jobDetail, trigger);
}

So I need to pass in the reminderRepo into the job as I am doing above

jobDetail.JobDataMap["reminderRepo"] = reminderRepo;

It’s the only way you can pass something into a job. Everytime the schedule gets executed a job is recreated and I am assuming it uses the same reminderRepo that I sent in.

My code in the service layer never gets executed again and of course the application start as well(unless I redeploy the site)

Job

 public class TaskReminderJob : IJob
    {


        public void Execute(JobExecutionContext context)
        {
            JobDataMap dataMap = context.JobDetail.JobDataMap;
            ReminderRepo reminderRepo = dataMap["reminderRepo"] as ReminderRepo;

            if (context.ScheduledFireTimeUtc.HasValue && context.NextFireTimeUtc.HasValue && reminderRepo != null)
            {
                DateTime start = context.ScheduledFireTimeUtc.Value;
                DateTime end = context.NextFireTimeUtc.Value;

                List<PersonalTaskReminder> personalTaskReminders = reminderRepo.GetPersonalTaskReminders(start, end);

                if (personalTaskReminders.Count > 0)
                {
                    reminderRepo.DeletePersonalTaskReminders(personalTaskReminders.Select(x => x.ReminderId).ToList());


                }

            }
        }

Reminder Repo. (When this repo gets instantiated a session should be given that will live till the end of the request)

  public class ReminderRepo : IReminderRepo
    {

        private readonly ISession session;

        public ReminderRepo(ISession session)
        {
            this.session = session;
        }

        public List<PersonalTaskReminder> GetPersonalTaskReminders(DateTime start, DateTime end)
        {
            List<PersonalTaskReminder> personalTaskReminders = session.Query<PersonalTaskReminder>().Where(x => x.DateToBeSent <= start && x.DateToBeSent <= end).ToList();
            return personalTaskReminders;
        }

        public void DeletePersonalTaskReminders(List<int> reminderId)
        {
            const string query = "DELETE FROM PersonalTaskReminder WHERE ReminderId IN (:reminderId)";
            session.CreateQuery(query).SetParameterList("reminderId", reminderId).ExecuteUpdate();
        }


        public void Commit()
        {
            using (ITransaction transaction = session.BeginTransaction())
            {
                transaction.Commit();
            }
        }


    }

So I need some way of keeping the session alive for my reminders. All my other sessions for all my other repos should be as I have it now. It’s only this one that seems to need to live forever.

Edit

I tried to get a new session each time so I am passing the IsessionFactory around. Probably not 100% best but it was the only way I could figure out how to get some new sessions.

I however do not know if my session are being closed through ninject still since I am manually passing in the session now. I thinking now but cannot verify.

 **private readonly ISessionFactory sessionFactory;**
private readonly ISchedulerFactory schedulerFactory;

public ScheduledRemindersService(ISessionFactory sessionFactory)
{
    **this.sessionFactory = sessionFactory;**
    schedulerFactory = new StdSchedulerFactory();
}

public void StartTaskRemindersSchedule()
{

    IScheduler scheduler = schedulerFactory.GetScheduler();

    scheduler.Start();

    JobDetail jobDetail = new JobDetail("TaskRemindersJob",null,typeof(TaskReminderJob));
    **jobDetail.JobDataMap["reminderRepo"] = sessionFactory;**

    DateTime evenMinuteDate = TriggerUtils.GetEvenMinuteDate(DateTime.UtcNow);


    SimpleTrigger trigger = new SimpleTrigger("TaskRemindersTrigger", null,
                        DateTime.UtcNow,
                        null,
                        SimpleTrigger.RepeatIndefinitely,
                        TimeSpan.FromMinutes(1));

    scheduler.ScheduleJob(jobDetail, trigger);
}

So my global.aspx is the same but since ninject now sees that “ScheduledRemindersService” now takes in a nhibernate session factory it binds one for me that I can use.

I then pass it off to the job.

public void Execute(JobExecutionContext context)
{
    JobDataMap dataMap = context.JobDetail.JobDataMap;
    ISessionFactory sessionFactory = dataMap["reminderRepo"] as ISessionFactory;

    if (sessionFactory != null)
    {
        ISession openSession = sessionFactory.OpenSession();
        ReminderRepo reminderRepo = new ReminderRepo(openSession);
    }
}

I then pass it into my ReminderRepo so I am guessing it ignores the auto session binding from ninject but I am not 100% sure thus I am not sure if my sessions are being closed.

Answer 1

Is there a reason the job can’t just open up a new session every time it runs? Presumably it’s running at periodic intervals and not forever ever.

Keeping stuff open forever is usually a sure-fire way to encounter weird behavior.

Hope this helps.