public async Task <string> PutMessagesBack()
{
if (_semaphoreSlim.CurrentCount == 0)
{
throw new Exception($"Cannot start the process because it was already started and not yet finished.");
}
await _semaphoreSlim.WaitAsync(TimeSpan.FromMinutes(10));
try
{
var factory = new ConnectionFactory {
Uri = new Uri(_brokerSettingsBase.MtRabbitMqConnString, UriKind.Absolute)
};
await _log.WriteInfoAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack),
$"Trying to connect to {factory.Endpoint} ({_rabbitMqSubscriptionSettings.ExchangeName})");
_connection = factory.CreateConnection();
var publishingChannel = _connection.CreateModel();
var subscriptionChannel = _connection.CreateModel();
_channels.AddRange(new[] { publishingChannel, subscriptionChannel });
var publishingArgs = new Dictionary <string, object>()
{
{ "x-dead-letter-exchange", _rabbitMqSubscriptionSettings.DeadLetterExchangeName }
};
subscriptionChannel.QueueDeclare(PoisonQueueName,
_rabbitMqSubscriptionSettings.IsDurable, false, false, null);
var messagesFound = subscriptionChannel.MessageCount(PoisonQueueName);
var processedMessages = 0;
var result = "Undefined";
if (messagesFound == 0)
{
result = "No messages found in poison queue. Terminating the process.";
await _log.WriteWarningAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack),
$"No messages found in poison queue. Terminating the process.");
FreeResources();
return(result);
}
else
{
await _log.WriteInfoAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack),
$"{messagesFound} messages found in poison queue. Starting the process.");
}
publishingChannel.QueueDeclare(_rabbitMqSubscriptionSettings.QueueName,
_rabbitMqSubscriptionSettings.IsDurable, false, false, publishingArgs);
var consumer = new EventingBasicConsumer(subscriptionChannel);
consumer.Received += (ch, ea) =>
{
var message = _brokerApplication.RepackMessage(ea.Body);
if (message != null)
{
try
{
IBasicProperties properties = null;
if (!string.IsNullOrEmpty(_brokerApplication.RoutingKey) ||
ea.BasicProperties?.Headers?.Count > 0)
{
properties = new BasicProperties();
if (!string.IsNullOrEmpty(_brokerApplication.RoutingKey))
{
properties.Type = _brokerApplication.RoutingKey;
}
if (ea.BasicProperties?.Headers?.Count > 0)
{
properties.Headers = ea.BasicProperties.Headers;
}
}
publishingChannel.BasicPublish(_rabbitMqSubscriptionSettings.ExchangeName,
_brokerApplication.RoutingKey ?? "", properties, message);
subscriptionChannel.BasicAck(ea.DeliveryTag, false);
processedMessages++;
}
catch (Exception e)
{
_log.WriteErrorAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack), $"Error resending message: {e.Message}", e);
}
}
};
var sw = new Stopwatch();
sw.Start();
var tag = subscriptionChannel.BasicConsume(PoisonQueueName, false,
consumer);
await _log.WriteInfoAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack),
$"Consumer {tag} started.");
while (processedMessages < messagesFound)
{
Thread.Sleep(100);
if (sw.ElapsedMilliseconds > 30000)
{
await _log.WriteWarningAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack),
$"Messages resend takes more than 30s. Terminating the process.");
break;
}
}
result =
$"Messages resend finished. Initial number of messages {messagesFound}. Processed number of messages {processedMessages}";
await _log.WriteInfoAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack), result);
FreeResources();
return(result);
}
catch (Exception exception)
{
var result =
$"Exception [{exception.Message}] thrown while putting messages back from poison to queue {_rabbitMqSubscriptionSettings.QueueName}. Stopping the process.";
await _log.WriteErrorAsync(nameof(RabbitPoisonHandingService), nameof(PutMessagesBack), result, exception);
return(result);
}
}
