Tapeti/Tapeti/Connection/TapetiClient.cs

632 lines
22 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using System.Web;
using Newtonsoft.Json;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using RabbitMQ.Client.Exceptions;
using RabbitMQ.Client.Framing;
using Tapeti.Config;
using Tapeti.Default;
using Tapeti.Exceptions;
using Tapeti.Tasks;
namespace Tapeti.Connection
{
/// <inheritdoc />
/// <summary>
/// Implementation of ITapetiClient for the RabbitMQ Client library
/// </summary>
public class TapetiClient : ITapetiClient
{
private const int ReconnectDelay = 5000;
private const int MandatoryReturnTimeout = 30000;
private const int MinimumConnectedReconnectDelay = 1000;
private readonly TapetiConnectionParams connectionParams;
private readonly ITapetiConfig config;
private readonly ILogger logger;
/// <summary>
/// Receives events when the connection state changes.
/// </summary>
public IConnectionEventListener ConnectionEventListener { get; set; }
private readonly Lazy<SingleThreadTaskQueue> taskQueue = new Lazy<SingleThreadTaskQueue>();
// These fields are for use in the taskQueue only!
private RabbitMQ.Client.IConnection connection;
private bool isClosing;
private bool isReconnect;
private IModel channelInstance;
private ulong lastDeliveryTag;
private DateTime connectedDateTime;
private HttpClient managementClient;
// These fields must be locked, since the callbacks for BasicAck/BasicReturn can run in a different thread
private readonly object confirmLock = new object();
private readonly Dictionary<ulong, ConfirmMessageInfo> confirmMessages = new Dictionary<ulong, ConfirmMessageInfo>();
private readonly Dictionary<string, ReturnInfo> returnRoutingKeys = new Dictionary<string, ReturnInfo>();
private class ConfirmMessageInfo
{
public string ReturnKey;
public TaskCompletionSource<int> CompletionSource;
}
private class ReturnInfo
{
public uint RefCount;
public int FirstReplyCode;
}
/// <inheritdoc />
public TapetiClient(ITapetiConfig config, TapetiConnectionParams connectionParams)
{
this.config = config;
this.connectionParams = connectionParams;
logger = config.DependencyResolver.Resolve<ILogger>();
var handler = new HttpClientHandler
{
Credentials = new NetworkCredential(connectionParams.Username, connectionParams.Password)
};
managementClient = new HttpClient(handler)
{
Timeout = TimeSpan.FromSeconds(30)
};
managementClient.DefaultRequestHeaders.Add("Connection", "close");
}
/// <inheritdoc />
public async Task Publish(byte[] body, IMessageProperties properties, string exchange, string routingKey, bool mandatory)
{
var publishProperties = new RabbitMQMessageProperties(new BasicProperties(), properties);
await taskQueue.Value.Add(async () =>
{
Task<int> publishResultTask = null;
var messageInfo = new ConfirmMessageInfo
{
ReturnKey = GetReturnKey(exchange, routingKey),
CompletionSource = new TaskCompletionSource<int>()
};
WithRetryableChannel(channel =>
{
// The delivery tag is lost after a reconnect, register under the new tag
if (config.Features.PublisherConfirms)
{
lastDeliveryTag++;
Monitor.Enter(confirmLock);
try
{
confirmMessages.Add(lastDeliveryTag, messageInfo);
}
finally
{
Monitor.Exit(confirmLock);
}
publishResultTask = messageInfo.CompletionSource.Task;
}
else
mandatory = false;
channel.BasicPublish(exchange, routingKey, mandatory, publishProperties.BasicProperties, body);
});
if (publishResultTask == null)
return;
var delayCancellationTokenSource = new CancellationTokenSource();
var signalledTask = await Task.WhenAny(
publishResultTask,
Task.Delay(MandatoryReturnTimeout, delayCancellationTokenSource.Token));
if (signalledTask != publishResultTask)
throw new TimeoutException(
$"Timeout while waiting for basic.return for message with exchange '{exchange}' and routing key '{routingKey}'");
delayCancellationTokenSource.Cancel();
if (publishResultTask.IsCanceled)
throw new NackException(
$"Mandatory message with with exchange '{exchange}' and routing key '{routingKey}' was nacked");
var replyCode = publishResultTask.Result;
// There is no RabbitMQ.Client.Framing.Constants value for this "No route" reply code
// at the time of writing...
if (replyCode == 312)
throw new NoRouteException(
$"Mandatory message with exchange '{exchange}' and routing key '{routingKey}' does not have a route");
if (replyCode > 0)
throw new NoRouteException(
$"Mandatory message with exchange '{exchange}' and routing key '{routingKey}' could not be delivered, reply code: {replyCode}");
});
}
/// <inheritdoc />
public async Task Consume(string queueName, IConsumer consumer)
{
if (string.IsNullOrEmpty(queueName))
throw new ArgumentNullException(nameof(queueName));
await taskQueue.Value.Add(() =>
{
WithRetryableChannel(channel =>
{
var basicConsumer = new TapetiBasicConsumer(consumer, Respond);
channel.BasicConsume(queueName, false, basicConsumer);
});
});
}
private async Task Respond(ulong deliveryTag, ConsumeResponse response)
{
await taskQueue.Value.Add(() =>
{
// No need for a retryable channel here, if the connection is lost we can't
// use the deliveryTag anymore.
switch (response)
{
case ConsumeResponse.Ack:
GetChannel().BasicAck(deliveryTag, false);
break;
case ConsumeResponse.Nack:
GetChannel().BasicNack(deliveryTag, false, false);
break;
case ConsumeResponse.Requeue:
GetChannel().BasicNack(deliveryTag, false, true);
break;
default:
throw new ArgumentOutOfRangeException(nameof(response), response, null);
}
});
}
/// <inheritdoc />
public async Task DurableQueueDeclare(string queueName, IEnumerable<QueueBinding> bindings)
{
await taskQueue.Value.Add(async () =>
{
var existingBindings = await GetQueueBindings(queueName);
WithRetryableChannel(channel =>
{
channel.QueueDeclare(queueName, true, false, false);
var currentBindings = bindings.ToList();
foreach (var binding in currentBindings)
channel.QueueBind(queueName, binding.Exchange, binding.RoutingKey);
foreach (var deletedBinding in existingBindings.Where(binding => !currentBindings.Any(b => b.Exchange == binding.Exchange && b.RoutingKey == binding.RoutingKey)))
channel.QueueUnbind(queueName, deletedBinding.Exchange, deletedBinding.RoutingKey);
});
});
}
/// <inheritdoc />
public async Task DurableQueueVerify(string queueName)
{
await taskQueue.Value.Add(() =>
{
WithRetryableChannel(channel =>
{
channel.QueueDeclarePassive(queueName);
});
});
}
/// <inheritdoc />
public async Task<string> DynamicQueueDeclare(string queuePrefix = null)
{
string queueName = null;
await taskQueue.Value.Add(() =>
{
WithRetryableChannel(channel =>
{
if (!string.IsNullOrEmpty(queuePrefix))
{
queueName = queuePrefix + "." + Guid.NewGuid().ToString("N");
channel.QueueDeclare(queueName);
}
else
queueName = channel.QueueDeclare().QueueName;
});
});
return queueName;
}
/// <inheritdoc />
public async Task DynamicQueueBind(string queueName, QueueBinding binding)
{
await taskQueue.Value.Add(() =>
{
WithRetryableChannel(channel =>
{
channel.QueueBind(queueName, binding.Exchange, binding.RoutingKey);
});
});
}
/// <inheritdoc />
public async Task Close()
{
if (!taskQueue.IsValueCreated)
return;
await taskQueue.Value.Add(() =>
{
isClosing = true;
if (channelInstance != null)
{
channelInstance.Dispose();
channelInstance = null;
}
// ReSharper disable once InvertIf
if (connection != null)
{
connection.Dispose();
connection = null;
}
taskQueue.Value.Dispose();
});
}
private static readonly List<HttpStatusCode> TransientStatusCodes = new List<HttpStatusCode>
{
HttpStatusCode.GatewayTimeout,
HttpStatusCode.RequestTimeout,
HttpStatusCode.ServiceUnavailable
};
private static readonly TimeSpan[] ExponentialBackoff =
{
TimeSpan.FromSeconds(1),
TimeSpan.FromSeconds(2),
TimeSpan.FromSeconds(3),
TimeSpan.FromSeconds(5),
TimeSpan.FromSeconds(8),
TimeSpan.FromSeconds(13),
TimeSpan.FromSeconds(21),
TimeSpan.FromSeconds(34),
TimeSpan.FromSeconds(55)
};
private class ManagementBinding
{
[JsonProperty("source")]
public string Source { get; set; }
[JsonProperty("vhost")]
public string Vhost { get; set; }
[JsonProperty("destination")]
public string Destination { get; set; }
[JsonProperty("destination_type")]
public string DestinationType { get; set; }
[JsonProperty("routing_key")]
public string RoutingKey { get; set; }
[JsonProperty("arguments")]
public Dictionary<string, string> Arguments { get; set; }
[JsonProperty("properties_key")]
public string PropertiesKey { get; set; }
}
private async Task<IEnumerable<QueueBinding>> GetQueueBindings(string queueName)
{
var virtualHostPath = Uri.EscapeDataString(connectionParams.VirtualHost);
var queuePath = Uri.EscapeDataString(queueName);
var requestUri = new Uri($"{connectionParams.HostName}:{connectionParams.Port}/api/queues/{virtualHostPath}/{queuePath}/bindings");
using (var request = new HttpRequestMessage(HttpMethod.Get, requestUri))
{
var retryDelayIndex = 0;
while (true)
{
try
{
var response = await managementClient.SendAsync(request);
response.EnsureSuccessStatusCode();
var content = await response.Content.ReadAsStringAsync();
var bindings = JsonConvert.DeserializeObject<IEnumerable<ManagementBinding>>(content);
// Filter out the binding to an empty source, which is always present for direct-to-queue routing
return bindings
.Where(binding => !string.IsNullOrEmpty(binding.Source))
.Select(binding => new QueueBinding(binding.Source, binding.RoutingKey));
}
catch (TimeoutException)
{
}
catch (WebException e)
{
if (!(e.Response is HttpWebResponse response))
throw;
if (!TransientStatusCodes.Contains(response.StatusCode))
throw;
}
await Task.Delay(ExponentialBackoff[retryDelayIndex]);
if (retryDelayIndex < ExponentialBackoff.Length - 1)
retryDelayIndex++;
}
}
}
/// <remarks>
/// Only call this from a task in the taskQueue to ensure IModel is only used
/// by a single thread, as is recommended in the RabbitMQ .NET Client documentation.
/// </remarks>
private void WithRetryableChannel(Action<IModel> operation)
{
while (true)
{
try
{
operation(GetChannel());
break;
}
catch (AlreadyClosedException)
{
}
}
}
/// <remarks>
/// Only call this from a task in the taskQueue to ensure IModel is only used
/// by a single thread, as is recommended in the RabbitMQ .NET Client documentation.
/// </remarks>
private IModel GetChannel()
{
if (channelInstance != null && channelInstance.IsOpen)
return channelInstance;
// If the Disconnect quickly follows the Connect (when an error occurs that is reported back by RabbitMQ
// not related to the connection), wait for a bit to avoid spamming the connection
if ((DateTime.UtcNow - connectedDateTime).TotalMilliseconds <= MinimumConnectedReconnectDelay)
Thread.Sleep(ReconnectDelay);
var connectionFactory = new ConnectionFactory
{
HostName = connectionParams.HostName,
Port = connectionParams.Port,
VirtualHost = connectionParams.VirtualHost,
UserName = connectionParams.Username,
Password = connectionParams.Password,
AutomaticRecoveryEnabled = false,
TopologyRecoveryEnabled = false,
RequestedHeartbeat = 30
};
while (true)
{
try
{
logger.Connect(connectionParams);
connection = connectionFactory.CreateConnection();
channelInstance = connection.CreateModel();
if (channelInstance == null)
throw new BrokerUnreachableException(null);
if (config.Features.PublisherConfirms)
{
lastDeliveryTag = 0;
Monitor.Enter(confirmLock);
try
{
foreach (var pair in confirmMessages)
pair.Value.CompletionSource.SetCanceled();
confirmMessages.Clear();
}
finally
{
Monitor.Exit(confirmLock);
}
channelInstance.ConfirmSelect();
}
if (connectionParams.PrefetchCount > 0)
channelInstance.BasicQos(0, connectionParams.PrefetchCount, false);
channelInstance.ModelShutdown += (sender, e) =>
{
ConnectionEventListener?.Disconnected(new DisconnectedEventArgs
{
ReplyCode = e.ReplyCode,
ReplyText = e.ReplyText
});
channelInstance = null;
if (!isClosing)
taskQueue.Value.Add(() => WithRetryableChannel(channel => { }));
};
channelInstance.BasicReturn += HandleBasicReturn;
channelInstance.BasicAcks += HandleBasicAck;
channelInstance.BasicNacks += HandleBasicNack;
connectedDateTime = DateTime.UtcNow;
if (isReconnect)
ConnectionEventListener?.Reconnected();
else
ConnectionEventListener?.Connected();
logger.ConnectSuccess(connectionParams);
isReconnect = true;
break;
}
catch (BrokerUnreachableException e)
{
logger.ConnectFailed(connectionParams, e);
Thread.Sleep(ReconnectDelay);
}
}
return channelInstance;
}
private void HandleBasicReturn(object sender, BasicReturnEventArgs e)
{
/*
* "If the message is also published as mandatory, the basic.return is sent to the client before basic.ack."
* - https://www.rabbitmq.com/confirms.html
*
* Because there is no delivery tag included in the basic.return message. This solution is modeled after
* user OhJeez' answer on StackOverflow:
*
* "Since all messages with the same routing key are routed the same way. I assumed that once I get a
* basic.return about a specific routing key, all messages with this routing key can be considered undelivered"
* https://stackoverflow.com/questions/21336659/how-to-tell-which-amqp-message-was-not-routed-from-basic-return-response
*/
var key = GetReturnKey(e.Exchange, e.RoutingKey);
if (!returnRoutingKeys.TryGetValue(key, out var returnInfo))
{
returnInfo = new ReturnInfo
{
RefCount = 0,
FirstReplyCode = e.ReplyCode
};
returnRoutingKeys.Add(key, returnInfo);
}
returnInfo.RefCount++;
}
private void HandleBasicAck(object sender, BasicAckEventArgs e)
{
Monitor.Enter(confirmLock);
try
{
foreach (var deliveryTag in GetDeliveryTags(e))
{
if (!confirmMessages.TryGetValue(deliveryTag, out var messageInfo))
continue;
if (returnRoutingKeys.TryGetValue(messageInfo.ReturnKey, out var returnInfo))
{
messageInfo.CompletionSource.SetResult(returnInfo.FirstReplyCode);
returnInfo.RefCount--;
if (returnInfo.RefCount == 0)
returnRoutingKeys.Remove(messageInfo.ReturnKey);
}
messageInfo.CompletionSource.SetResult(0);
confirmMessages.Remove(deliveryTag);
}
}
finally
{
Monitor.Exit(confirmLock);
}
}
private void HandleBasicNack(object sender, BasicNackEventArgs e)
{
Monitor.Enter(confirmLock);
try
{
foreach (var deliveryTag in GetDeliveryTags(e))
{
if (!confirmMessages.TryGetValue(deliveryTag, out var messageInfo))
continue;
messageInfo.CompletionSource.SetCanceled();
confirmMessages.Remove(e.DeliveryTag);
}
}
finally
{
Monitor.Exit(confirmLock);
}
}
private IEnumerable<ulong> GetDeliveryTags(BasicAckEventArgs e)
{
return e.Multiple
? confirmMessages.Keys.Where(tag => tag <= e.DeliveryTag).ToArray()
: new[] { e.DeliveryTag };
}
private IEnumerable<ulong> GetDeliveryTags(BasicNackEventArgs e)
{
return e.Multiple
? confirmMessages.Keys.Where(tag => tag <= e.DeliveryTag).ToArray()
: new[] { e.DeliveryTag };
}
private static string GetReturnKey(string exchange, string routingKey)
{
return exchange + ':' + routingKey;
}
}
}