Sometimes facing this exception: RabbitMQ.Client.Exceptions.ChannelAllocationException

[ajaykem181]

Code

using log4net;
using LogzLoggerProvider;
using Microsoft.Extensions.Configuration;
using RabbitMQ.Client;
using System;
using System.Collections.Concurrent;
using System.IO;
using System.Threading;

namespace MarketicEventApi.RabbitMQ
{
    public abstract class RabbitMqClientBase : IDisposable
    {
        private static readonly ILog _logger = LogManager.GetLogger(typeof(ConsumerBase));
        protected string Exchange;
        protected readonly string ExternalSourceQueue;
        protected readonly string ExternalSourceRoutingKey;

        protected readonly string WebsiteQueue;
        protected readonly string WebsiteRoutingKey;
        protected readonly string BookmarkQueue;
        protected readonly string BookmarkRoutingKey;

        protected readonly string TrackEventQueue;
        protected readonly string TrackEventRoutingKey;

        protected readonly string IdentifyEventQueue;
        protected readonly string IdentifyEventRoutingKey;

        protected readonly string ExpiredActionInstanceQueue;
        protected readonly string ExpiredActionInstanceRoutingKey;


        protected IModel Channel { get; private set; }
        private IConnection _connection;
        private readonly ConnectionFactory _connectionFactory;

        protected RabbitMqClientBase(
            ConnectionFactory connectionFactory, IConfiguration configuration)
        {
            Exchange = configuration.GetValue<string>("marketicui:rabbitmq:exchange");
            ExternalSourceQueue = configuration.GetValue<string>("marketicui:rabbitmq:externalSourceQueue");
            ExternalSourceRoutingKey = configuration.GetValue<string>("marketicui:rabbitmq:externalSourceRoutingKey");
            WebsiteQueue = configuration.GetValue<string>("marketicui:rabbitmq:websiteQueue");
            WebsiteRoutingKey = configuration.GetValue<string>("marketicui:rabbitmq:websiteRoutingKey");
            TrackEventQueue = configuration.GetValue<string>("marketicui:rabbitmq:trackEventQueue");
            TrackEventRoutingKey = configuration.GetValue<string>("marketicui:rabbitmq:trackEventRoutingKey");
            IdentifyEventQueue = configuration.GetValue<string>("marketicui:rabbitmq:identifyEventQueue");
            IdentifyEventRoutingKey = configuration.GetValue<string>("marketicui:rabbitmq:identifyEventRoutingKey");
            BookmarkQueue = configuration.GetValue<string>("marketicui:rabbitmq:bookmarkQueue");
            BookmarkRoutingKey = configuration.GetValue<string>("marketicui:rabbitmq:bookmarkRoutingKey");
            ExpiredActionInstanceQueue = configuration.GetValue<string>("marketicui:rabbitmq:expiredactioninstancequeue");
            ExpiredActionInstanceRoutingKey = configuration.GetValue<string>("marketicui:rabbitmq:expiredactioninstanceroutingKey");
            _connectionFactory = connectionFactory;
            ConnectToRabbitMq();
        }

        private void ConnectToRabbitMq()
        {
            _logger.ServiceStarted("Start attempting connection to rabbit mq");

            if (_connection == null || _connection.IsOpen == false)
            {
                _logger.ServiceProcessing("Create connection to rabbit mq");
                _connectionFactory.AutomaticRecoveryEnabled = true;
                _connection = _connectionFactory.CreateConnection();
                _connection.ConnectionShutdown += Connection_ConnectionShutdown;
            }

            _logger.ServiceProcessing("Create channel model and bind queue in rabbit mq");

            if (Channel == null || Channel.IsOpen == false)
            {
                Channel = _connection.CreateModel();
                Channel.ExchangeDeclare(
                    exchange: Exchange,
                    type: "topic",
                    durable: true,
                    autoDelete: false);

                Channel.QueueDeclare(
                    queue: ExternalSourceQueue,
                    durable: true,
                    exclusive: false,
                    autoDelete: false);

                Channel.QueueBind(
                    queue: ExternalSourceQueue,
                    exchange: Exchange,
                    routingKey: ExternalSourceRoutingKey);

                Channel.QueueDeclare(
                    queue: WebsiteQueue,
                    durable: true,
                    exclusive: false,
                    autoDelete: false);

                Channel.QueueBind(
                    queue: WebsiteQueue,
                    exchange: Exchange,
                    routingKey: WebsiteRoutingKey);

                Channel.QueueDeclare(
                    queue: BookmarkQueue,
                    durable: true,
                    exclusive: false,
                    autoDelete: false);

                Channel.QueueBind(
                    queue: BookmarkQueue,
                    exchange: Exchange,
                    routingKey: BookmarkRoutingKey);

                Channel.QueueDeclare(
                    queue: TrackEventQueue,
                    durable: true,
                    exclusive: false,
                    autoDelete: false);

                Channel.QueueBind(
                    queue: TrackEventQueue,
                    exchange: Exchange,
                    routingKey: TrackEventRoutingKey);

                Channel.QueueDeclare(
                    queue: IdentifyEventQueue,
                    durable: true,
                    exclusive: false,
                    autoDelete: false);

                Channel.QueueBind(
                    queue: IdentifyEventQueue,
                    exchange: Exchange,
                    routingKey: IdentifyEventRoutingKey);

                Channel.QueueDeclare(
                    queue: ExpiredActionInstanceQueue,
                    durable: true,
                    exclusive: false,
                    autoDelete: false);

                Channel.QueueBind(
                    queue: ExpiredActionInstanceQueue,
                    exchange: Exchange,
                    routingKey: ExpiredActionInstanceRoutingKey);
            }
        }

        public void Dispose()
        {
            _logger.ServiceProcessing("Rabbit mq connection and channel dispose");

            try
            {
                Channel?.Close();
                Channel?.Dispose();
                Channel = null;

                _connection?.Close();
                _connection?.Dispose();
                _connection = null;
            }
            catch (Exception ex)
            {
                _logger.ServiceFaulted(ex, "Rabbit mq connection and channel dispose failed");
            }
        }

        private void Connection_ConnectionShutdown(object sender, ShutdownEventArgs e)
        {
            _logger.ServiceProcessing("Rabbit mq connection shutdown event handler called");

            Cleanup();

            while (true)
            {
                try
                {
                    ConnectToRabbitMq();

                    _logger.ServiceFinishedSuccess("Rabbit mq connection reconnected successfully");

                    break;
                }
                catch (Exception ex)
                {
                    _logger.ServiceFaulted(ex, "Rabbit mq reconnection failed");

                    Thread.Sleep(3000);
                }
            }
        }

        private void Cleanup()
        {
           _logger.ServiceProcessing("Close existing rabbit mq channel if exists");

            try
            {
                if (Channel != null && Channel.IsOpen)
                {
                    Channel.Close();
                    Channel = null;
                }

                if (_connection != null && _connection.IsOpen)
                {
                    _connection.Close();
                    _connection = null;
                }
            }
            catch (IOException ex)
            {
                _logger.ServiceFaulted(ex, "Rabbit mq connection close failed");
            }
        }
    }
}

[lukebakken]

Your code has duplicated this library's reconnection logic. In Connection_ConnectionShutdown, do NOT reconnect.

[ajaykem181]

@lukebakken , @michaelklishin ,
Sorry, I didn't mention that TestWebAPI is acknowledging messages & TestApiMessagePublisher has a backgroundworker which publish messages.
I had removed ConsoleAppRabbitMQ from solution, it was just there to check if ChannelAllocationException exception occurs when channels limit 2047 is crossed & then i started searching for solution, as same error was logged in my application.

[ajaykem181]

I don't understand what you are trying to demonstrate with this code:

https://github.com/lukebakken/rabbitmq-dotnet-client-1637/blob/main/ConsoleAppRabbitMQ/Program.cs

Of course you are going to run into a channel allocation exception at some point - you are allocating them in a loop.

I deleted the other projects because it was not clear why they were included.

You need to provide better instructions for me to follow.

Please do not follow this Console App, consider other two API applications as I mentioned in earlier comment.
ConsoleAppRabbitMQ.zip

[lukebakken]

consider other two API applications as I mentioned in earlier comment

How do I run and use them, and then test your scenario? I do NOT have the time to guess.

I will only investigate if you give me precise instructions.

[ajaykem181]

Its created on dot net 6.0, If you are able to build the solution. Then both applications should be executed together, BackgroundService in TestApiMessagePublisher will publish messages TestWebAPI will consume messages.

[lukebakken]

And then what? Forcefully close a connection? Please take the time to be precise and list EVERY step.

Also, please see this comment - #1637 (comment)

I can't build your code.

[lukebakken]

@ajaykem181 your code from this comment does not build:

C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637 [main ≡]
> dotnet build .\ConsoleAppRabbitMQ.sln
  Determining projects to restore...
C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\TestApiMessagePublisher\TestApiMessagePublisher.csproj : error NU1101: Unable to find package RabbitMQHelper. No packages exist with this id in source(s): Microsoft Visu
al Studio Offline Packages, nuget.org [C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\ConsoleAppRabbitMQ.sln]
C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\TestWebAPI\TestWebAPI.csproj : error NU1101: Unable to find package RabbitMQHelper. No packages exist with this id in source(s): Microsoft Visual Studio Offline Packages
, nuget.org [C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\ConsoleAppRabbitMQ.sln]
  Failed to restore C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\TestApiMessagePublisher\TestApiMessagePublisher.csproj (in 491 ms).
  Failed to restore C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\TestWebAPI\TestWebAPI.csproj (in 491 ms).

Build FAILED.

C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\TestApiMessagePublisher\TestApiMessagePublisher.csproj : error NU1101: Unable to find package RabbitMQHelper. No packages exist with this id in source(s): Microsoft Visu
al Studio Offline Packages, nuget.org [C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\ConsoleAppRabbitMQ.sln]
C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\TestWebAPI\TestWebAPI.csproj : error NU1101: Unable to find package RabbitMQHelper. No packages exist with this id in source(s): Microsoft Visual Studio Offline Packages
, nuget.org [C:\Users\lbakken\development\lukebakken\rabbitmq-dotnet-client-1637\ConsoleAppRabbitMQ.sln]
    0 Warning(s)
    2 Error(s)

I have checked in your latest code to this repository:

https://github.com/lukebakken/rabbitmq-dotnet-client-1637

Please fork my repository, make the necessary fixes, and open a pull request so that I can merge them.