RabbitMQ -- Masstransit 异常处理

Exception

public class SubmitOrderConsumer :
IConsumer
{
public Task Consume(ConsumeContext context)
{
throw new Exception(“Very bad things happened”);
}
}
UseMessageRetry

var sessionFactory = CreateSessionFactory();

var busControl = Bus.Factory.CreateUsingRabbitMq(cfg =>
{
cfg.Host(“rabbitmq://localhost/”);

cfg.ReceiveEndpoint("submit-order", e =>
{
    e.UseMessageRetry(r => r.Immediate(5));

    e.Consumer(() => new SubmitOrderConsumer(sessionFactory));
});

});
重试配置

// 立即重试：一共连续重试10次
ep.UseMessageRetry(r => r.Immediate(10));

// 间隔重试：一共重试10次，每次间隔10秒
ep.UseMessageRetry(r => r.Interval(10, TimeSpan.FromSeconds(10)));

// 多个间隔重试：5秒后第一次，5+10秒后第二次，5+10+15秒后第三次
ep.UseMessageRetry(r => r.Intervals(TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(15)));

// 指数级间隔重试：共10次，每次间隔：当前重试次数 * 60秒
ep.UseMessageRetry(r => r.Exponential(10, TimeSpan.FromSeconds(60), TimeSpan.FromHours(24), TimeSpan.FromSeconds(60)));

// 每次叠加50秒
ep.UseMessageRetry(r => r.Incremental(10, TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(50)));
重试条件
e.UseMessageRetry(r =>
{
r.Handle();
r.Ignore(typeof(InvalidOperationException), typeof(InvalidCastException));
r.Ignore(t => t.ParamName == “orderTotal”);
});
过滤某些异常类型不进行重试

重新投递信息
cfg.ReceiveEndpoint(“submit-order”, e =>
{
e.UseScheduledRedelivery(r => r.Intervals(TimeSpan.FromMinutes(5), TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(30)));
e.UseMessageRetry(r => r.Immediate(5));
e.Consumer(() => new SubmitOrderConsumer(sessionFactory));
});
消息冲队列移除之后，在一定时间之后重新投入消息队列。需要配置调度模块（scheduling）

信箱
cfg.ReceiveEndpoint(“submit-order”, e =>
{
e.UseScheduledRedelivery(r => r.Intervals(TimeSpan.FromMinutes(5), TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(30)));
e.UseMessageRetry(r => r.Immediate(5));
e.UseInMemoryOutbox();

e.Consumer(() => new SubmitOrderConsumer(sessionFactory));

});
有些消息是在 consume 方法中发送或发布的，如果在发送之后 consume 中产生了异常，那原来发出去的消息就需要撤回，如果使用信箱之后，在 consume 中要发布/发送的消息就会先暂存在内存中直到 consume 方法成功之后才真正发出去

其他
Fault
Consuming Faults
Error Pipe
Dead-Letter Pipe
Fault
public interface Fault
where T : class
{
Guid FaultId { get; }
Guid? FaultedMessageId { get; }
DateTime Timestamp { get; }
ExceptionInfo[] Exceptions { get; }
HostInfo Host { get; }
T Message { get; }
}
Fault 消息在异常的时候会发布出来

Consuming Faults
public class DashboardFaultConsumer :
IConsumer<Fault>
{
public async Task Consume(ConsumeContext<Fault> context)
{
// update the dashboard
}
}
Fault 消息也是可以进行订阅的

Error Pipe
cfg.ReceiveEndpoint(“input-queue”, ec =>
{
ec.DiscardFaultedMessages();
});
默认情况下错误的消息会被投递到了 _error 队列，可以配置直接抛弃错误信息

Dead-Letter Pipe
cfg.ReceiveEndpoint(“input-queue”, ec =>
{
ec.DiscardSkippedMessages();
});

亚马逊测评 www.yisuping.cn