标签:hostname object qos connect system oba bit static 技术
假如现在有个需求,我们需要让一些优先级最高的通知推送到客户端,我们可以使用redis的sortedset,也可以使用我们今天要说的rabbit的消息优先级属性
Producer代码
using RabbitMQ.Client; using System; using System.Collections.Generic; using System.Text; using System.Threading; using System.Threading.Tasks; namespace RabbitMQConsole { class Program { static void Main(string[] args) { ConnectionFactory factory = new ConnectionFactory(); factory.HostName = "39.**.**.**"; factory.Port = 5672; factory.VirtualHost = "/"; factory.UserName = "root"; factory.Password = "root"; var exchange = "change4"; var route = "route2"; var queue9 = "queue9"; using (var connection = factory.CreateConnection()) { using (var channel = connection.CreateModel()) { channel.ExchangeDeclare(exchange, type: "fanout", durable: true, autoDelete: false); //x-max-priority属性必须设置,否则消息优先级不生效 channel.QueueDeclare(queue9, durable: true, exclusive: false, autoDelete: false,arguments: new Dictionary<string, object> { { "x-max-priority", 50 } }); channel.QueueBind(queue9, exchange, queue9); while(true) { var messagestr = Console.ReadLine(); var messagepri = Console.ReadLine(); var props = channel.CreateBasicProperties(); props.Persistent = true; props.Priority = (byte)int.Parse(messagepri);//设置消息优先级 channel.BasicPublish(exchange, route, true, props, Encoding.UTF8.GetBytes(messagestr)); } } } } } }
consumer代码
using RabbitMQ.Client; using RabbitMQ.Client.Events; using System; using System.Collections.Generic; using System.Text; using System.Threading; namespace RabbitMQClient { class Program { private static readonly ConnectionFactory rabbitMqFactory = new ConnectionFactory() { HostName = "39.**.**.**", Port = 5672, UserName = "root", Password = "root", VirtualHost = "/" }; static void Main(string[] args) { var exchange = "change4"; var route = "route2"; var queue9 = "queue9"; using (IConnection conn = rabbitMqFactory.CreateConnection()) using (IModel channel = conn.CreateModel()) { channel.ExchangeDeclare(exchange, "fanout", durable: true, autoDelete: false); channel.QueueDeclare(queue9, durable: true, exclusive: false, autoDelete: false, arguments: new Dictionary<string, object> { { "x-max-priority", 50 } }); channel.QueueBind(queue9, exchange, route); channel.BasicQos(prefetchSize: 0, prefetchCount: 50, global: false); EventingBasicConsumer consumer = new EventingBasicConsumer(channel); consumer.Received += (model, ea) => { Byte[] body = ea.Body; String message = Encoding.UTF8.GetString(body); Console.WriteLine( message); channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false); }; channel.BasicConsume(queue: queue9, autoAck: false, consumer: consumer); Console.ReadLine(); } } } }
运行producer
在运行consumer
可以看出消息是按优先级消费的
死信队列可以用来做容错机制,当我们的消息处理异常时我们可以把消息放入到死信队列中,以便后期处理,死信的产生有三种
1.消息被拒(basic.reject or basic.nack)并且没有重新入队(requeue=false);
2.当前队列中的消息数量已经超过最大长度。
3.消息在队列中过期,即当前消息在队列中的存活时间已经超过了预先设置的TTL(Time To Live)时间;
看代码
using RabbitMQ.Client; using System; using System.Collections.Generic; using System.Text; using System.Threading; using System.Threading.Tasks; namespace RabbitMQConsole { class Program { static void Main(string[] args) { ConnectionFactory factory = new ConnectionFactory(); factory.HostName = "39.**.**.**"; factory.Port = 5672; factory.VirtualHost = "/"; factory.UserName = "root"; factory.Password = "root"; var exchangeA = "changeA"; var routeA = "routeA"; var queueA = "queueA"; var exchangeD = "changeD"; var routeD = "routeD"; var queueD = "queueD"; using (var connection = factory.CreateConnection()) { using (var channel = connection.CreateModel()) { channel.ExchangeDeclare(exchangeD, type: "fanout", durable: true, autoDelete: false); channel.QueueDeclare(queueD, durable: true, exclusive: false, autoDelete: false); channel.QueueBind(queueD, exchangeD, routeD); channel.ExchangeDeclare(exchangeA, type: "fanout", durable: true, autoDelete: false); channel.QueueDeclare(queueA, durable: true, exclusive: false, autoDelete: false, arguments: new Dictionary<string, object> { { "x-dead-letter-exchange",exchangeD}, //设置当前队列的DLX { "x-dead-letter-routing-key",routeD}, //设置DLX的路由key,DLX会根据该值去找到死信消息存放的队列 { "x-message-ttl",10000} //设置消息的存活时间,即过期时间 }); channel.QueueBind(queueA, exchangeA, routeA); var properties = channel.CreateBasicProperties(); properties.Persistent = true; //发布消息 channel.BasicPublish(exchange: exchangeA, routingKey: routeA, basicProperties: properties, body: Encoding.UTF8.GetBytes("message")); } } } } }
这样10秒后消息过期,我们可以看到queueD中有了消息
RabbitMQ与.net core(四) 消息的优先级 与 死信队列
标签:hostname object qos connect system oba bit static 技术
原文地址:https://www.cnblogs.com/chenyishi/p/10242162.html