JN.RabbitMQClient 2.5.1

JN.RabbitMQClient

Simple implementation of RabbitMQ consumer and sender.

Features

• Sender implementation
• Multiple consumer instances supported
• Multiple processing options for received messages
• Random expiration for messages sent to an holding queue (depending on the processing option)
• TLS connection support
• Limiter for message processing
• Message properties for more advanced scenarios such as queues with support for priority messages, messages Headers, etc.

More details available on the project website.

Install

Download the package from NuGet:

Install-Package JN.RabbitMQClient -Version [version number]

Usage

First, you must create the RabbitMqConsumerService and then define delegates for ReceiveMessage, ShutdownConsumer and ReceiveMessageError. The service will start the required number of consumers when StartConsumers is called.

To use a retry queue, the method StartConsumers should be called with a RetryQueueDetails object.

Message processing instructions

OK - message is considered as successfully processed

RequeueMessageWithDelay - message is removed from the queue, but sent to a holding queue for later processing (typically with a dead letter configuration)

IgnoreMessage - message is removed from the queue and ignored

IgnoreMessageWithRequeue - message is rejected and sent back to the queue

Example

Example for consumer and sender services:

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            // consumer

            // you can also use extensions AddConsumersService() and AddSenderService() (in namespace JN.RabbitMQClient.Extensions)

            var consumerService = new RabbitMqConsumerService(GetBrokerConfigConsumers());

            consumerService.ReceiveMessage += ReceiveMessage;
            consumerService.ShutdownConsumer += ShutdownConsumer;
            consumerService.ReceiveMessageError += ReceiveMessageError;
            consumerService.MaxChannelsPerConnection = 5;
            consumerService.ConsumersPrefetch = 2;
            consumerService.ServiceDescription = "test consumer service";

            consumerService.StartConsumers("my consumer");
 
            // sender

            var senderService = new RabbitMqSenderService(GetBrokerConfigSender());

            IMessageProperties properties = new MessageProperties { Priority = 3 };

            var result = senderService.Send("my message", properties);

            Console.WriteLine($"Send result: {result.Success}");
            Console.WriteLine(result.ReturnedObject != null
                ? $"Queue details. ConsumerCount: {result.ReturnedObject.ConsumerCount}; MessageCount: {result.ReturnedObject.MessageReadyCount}"
                : $"Unable to obtain queue details. Reason: {result.ErrorDescription}");

            Console.WriteLine("Press any key to exit...");
            Console.ReadKey();

            consumerService.Dispose();
        }

        private static IBrokerConfigSender GetBrokerConfigSender()
        {
            IBrokerConfigSender configSender = new BrokerConfigSender
            {
                Username = "test",
                Password = "123",
                Host = hostName,
                VirtualHost = "MyVirtualHost",
                RoutingKeyOrQueueName = "MyTestQueue",
                KeepConnectionOpen = true,
                GetQueueInfoOnSend = true
            };
            return configSender;
        }

        private static IBrokerConfigConsumers GetBrokerConfigConsumers()
        {
            IBrokerConfigConsumers configConsumers = new BrokerConfigConsumers
            {
                Username = "test",
                Password = "123",
                Host = hostName,
                VirtualHost = "MyVirtualHost",
                RoutingKeyOrQueueName = "MyTestQueue",
                ShuffleHostList = false,
                Port = 0,
                TotalInstances = 4
            };
            return configConsumers;
        }

        private static async Task ReceiveMessageError(string routingKeyOrQueueName, string consumerTag, string exchange, string message, string errorMessage)
        {
            await Console.Out.WriteLineAsync($"Error: '{consumerTag}' | Queued message: {message} | Error message: {errorMessage}").ConfigureAwait(false);
        }

        private static async Task ShutdownConsumer(string consumerTag, ushort errorCode, string shutdownInitiator, string errorMessage)
        {
            await Console.Out.WriteLineAsync($"Shutdown '{consumerTag}' | {errorCode} | {shutdownInitiator} | {errorMessage}").ConfigureAwait(false);
        }

        private static async Task<MessageProcessInstruction> ReceiveMessage(string routingKeyOrQueueName, string consumerTag, long firstErrorTimestamp, string exchange, string message, string additionalInfo, IMessageProperties properties)
        {
            var priorityReceived = properties.Priority;

            var newPriority = (byte)(priorityReceived <= 3 ? 5 : priorityReceived);

            await Console.Out.WriteLineAsync($"Message received by '{consumerTag}' from queue '{routingKeyOrQueueName}': {message}; Priority received: {properties.Priority} ").ConfigureAwait(false);
            
            return new MessageProcessInstruction
            {
                Value = Constants.MessageProcessInstruction.OK,
                Priority = newPriority,
                AdditionalInfo = "id: 123"
            };
        }
    }