ABP framework / parallel programming - abp

Question

I have one AsyncPeriodicBackgroundWorkerBase base class(DataValidateWorker) which runs 1 minute interval.
I need to send the data I get from the DB to a third party web service and update the results in the db. A Web service response arrives in about 30-40 seconds. For this reason, I need to send Web service queries simultaneously, not sequentially.
For this reason, I wrote code in accordance with parallel programming as seen below. I cannot pull the database connection for the Task I wrote. DB connection closed, I got many errors like Executing.
How can I create the db connection for my Task?
Would it be better to write this job in an external application (exe or service) instead of ABP?
public class DataValidateWorker : AsyncPeriodicBackgroundWorkerBase
{
private readonly IUnitOfWorkManager _unitOfWorkManager;
private readonly IDataFilter _dataFilter;
public DataValidateWorker(AbpAsyncTimer timer, IServiceScopeFactory serviceScopeFactory, IDataFilter dataFilter, IUnitOfWorkManager unitOfWorkManager) : base(timer, serviceScopeFactory)
{
_dataFilter = dataFilter;
_unitOfWorkManager = unitOfWorkManager;
Timer.Period = 60 * 1000; // 60 seconds
}
[UnitOfWork]
protected async override Task DoWorkAsync(PeriodicBackgroundWorkerContext workerContext)
{
try
{
var notificationValidationRepository = workerContext.ServiceProvider.GetRequiredService<IRepository<NotificationValidation, int>>();
var notificationValidationItems = await notificationValidationRepository.GetQueryableAsync();
List<NotificationValidation> list = new List<NotificationValidation>();
using (var uow = _unitOfWorkManager.Begin())
{
using (_dataFilter.Disable<IMultiTenant>())
{
list = notificationValidationItems.Where(x => x.RecordDateTime <= DateTime.Now && x.ValidationResult == (int)ValidationResult.NotStarted).ToList();
}
}
NotificationValidationArgs jobArgs = new NotificationValidationArgs();
foreach (var item in list)
{
jobArgs.notificationValidationId = item.Id;
Task taskA = Task.Factory.StartNew(async (Object obj) =>
{
// doing some third party web service operations and db operations
}, jobArgs);
}
}
catch (Exception ex)
{
Logger.LogCritical(2001, ex, DateTime.Now.ToString() + " -> DataValidateWorker -> try 1 -> RDMS uow");
}
}
}

Answer 1

You don't await any of tasks, so lifetime of object ends while your task is still running.
Try to store all of the tasks in a collection and await them before method execution finishes.
Something like below:
public class DataValidateWorker : AsyncPeriodicBackgroundWorkerBase
{
public DataValidateWorker(AbpAsyncTimer timer, IServiceScopeFactory serviceScopeFactory) : base(timer, serviceScopeFactory)
{
}
protected override async Task DoWorkAsync(PeriodicBackgroundWorkerContext workerContext)
{
var tasks = new List<Task>();
foreach (var item in list)
{
tasks.Add(YourLongJob(arg)); // don't await here. collect in a collection
}
await Task.WhenAll(tasks); // wait until all of them is completed.
}
private async Task YourLongJob(object arg)
{
await Task.Delay(30 * 1000); // a long job
}
}