protected async Task BackgroundProcessing(CancellationToken cancellationToken)
{
bool hasItems = true;
while (!cancellationToken.IsCancellationRequested)
{
try
{
var allItems = new List <QueueItem>();
using (var connection = sqlConnectionFactory.GetConnection())
{
await sqlConnectionFactory.OpenAsync(connection, cancellationToken);
if (!hasItems)
{
hasItems = await queueItemRepository.HasItems(connection);
if (!hasItems)
{
logger.LogInformation($"No items to process, going to sleep for {config.NoQueueItemsToProcessSleepTimeMS} milliseconds");
await Task.Delay(config.NoQueueItemsToProcessSleepTimeMS, cancellationToken);
sqlConnectionFactory.Close(connection);
continue;
}
}
var workers = await queueWorkerRepository.GetQueueWorkers(connection);
foreach (var worker in workers.Where(w => w.Enabled).OrderByDescending(w => w.Priority))
{
var items = await queueItemRepository.GetQueueItems(connection, worker.Id, worker.Retries, worker.BatchSize);
items.ForEach(i => i.QueueWorker = worker);
allItems.AddRange(items);
if (allItems.Count > config.GlobalBatchSizeLimit)
{
break;
}
}
sqlConnectionFactory.Close(connection);
}
if (!allItems.Any())
{
logger.LogInformation($"No items to process, going to sleep for {config.NoQueueItemsToProcessSleepTimeMS} milliseconds");
hasItems = false;
await Task.Delay(config.NoQueueItemsToProcessSleepTimeMS, cancellationToken);
continue;
}
var allTasks = new List <Task>();
foreach (var item in allItems.OrderByDescending(i => i.QueueWorker.Priority).ThenBy(i => i.Id))
{
allTasks.Add(ProcessItem(item, cancellationToken));
}
await Task.WhenAll(allTasks);
}
catch (Exception ex)
{
logger.LogError(ex, $"Error processing queue.");
await Task.Delay(config.NoQueueItemsToProcessSleepTimeMS, cancellationToken);
}
}
logger.LogInformation("QueueProcessor Service is cancelled.");
}