php - RabbitMQ 收到消息但无处可去

Question

我在 PuPHPet 上安装了 RabbitMQ - 在 Windows 10 之上生成虚拟框 (Ubuntu 16.04 x64)。

设置完成后，我使用 rabbitmqctl 配置了一个新用户:

# rabbitmqctl add_user root root
# rabbitmqctl set_permissions -p / root ".*" ".*" ".*"
# rabbitmqctl set_user_tags root administrator

在 PHP & RabbitMQ Tutorial 之后, 我设置了一个发送者和接收者脚本。

发送脚本如下:

<?php
require_once 'vendor/autoload.php';

use PhpAmqpLib\Connection\AMQPStreamConnection;
use PhpAmqpLib\Message\AMQPMessage;

$connection = new AMQPStreamConnection('localhost', 5672, 'root', 'root');
$channel = $connection->channel();
$channel->queue_declare('my_queue', false, false, false, false);

$msg = new AMQPMessage('Hello World!');
$channel->basic_publish($msg, '', 'hello');

echo "Sent 'Hello World!'\n";

$channel->close();
$connection->close();

接收脚本如下:

<?php
require_once __DIR__ . '/vendor/autoload.php';
use PhpAmqpLib\Connection\AMQPStreamConnection;
$connection = new AMQPStreamConnection('localhost', 5672, 'root', 'root');
$channel = $connection->channel();
$channel->queue_declare('my_queue', false, false, false, false);
echo ' [*] Waiting for messages. To exit press CTRL+C', "\n";
$callback = function($msg) {
    echo " [x] Received ", $msg->body, "\n";
};
$channel->basic_consume('my_queue', '', false, true, false, false, $callback);
while(count($channel->callbacks)) {
    $channel->wait();
}
$channel->close();
$connection->close();
?>

我为接收方脚本打开了一个屏幕，并触发了发送方脚本的几次执行:

$ php sender.php
Sent 'Hello World!'

发送方脚本没有遇到任何错误(我能够验证队列是在 rabbit 中声明的)，但是接收方没有输出它已经接收/消费了任何消息。

此外，使用 admin manager 插件进行的快速检查显示队列中根本没有消息:

$ curl -i -u root:root http://localhost:15672/api/queues
...
{  
    "messages_details":{  
        "rate":0.0
    },
    "messages":0,
    "messages_unacknowledged_details":{  
        "rate":0.0
    },
    "messages_unacknowledged":0,
    "messages_ready_details":{  
        "rate":0.0
    },
    "messages_ready":0,
    "reductions_details":{  
        "rate":0.0
    },
    "reductions":9294,
    "node":"rabbit@leon",
    "arguments":{  

    },
    "exclusive":false,
    "auto_delete":false,
    "durable":false,
    "vhost":"/",
    "name":"my_queue",
    "message_bytes_paged_out":0,
    "messages_paged_out":0,
    "backing_queue_status":{  
        "avg_ack_egress_rate":0.0,
        "avg_ack_ingress_rate":0.0,
        "avg_egress_rate":0.0,
        "avg_ingress_rate":0.0,
        "delta":[  
            "delta",
            "undefined",
            0,
            0,
            "undefined"
        ],
        "len":0,
        "mode":"default",
        "next_seq_id":0,
        "q1":0,
        "q2":0,
        "q3":0,
        "q4":0,
        "target_ram_count":"infinity"
    },
    "head_message_timestamp":null,
    "message_bytes_persistent":0,
    "message_bytes_ram":0,
    "message_bytes_unacknowledged":0,
    "message_bytes_ready":0,
    "message_bytes":0,
    "messages_persistent":0,
    "messages_unacknowledged_ram":0,
    "messages_ready_ram":0,
    "messages_ram":0,
    "garbage_collection":{  
        "minor_gcs":12,
        "fullsweep_after":65535,
        "min_heap_size":233,
        "min_bin_vheap_size":46422,
        "max_heap_size":0
    },
    "state":"running",
    "recoverable_slaves":null,
    "consumers":0,
    "exclusive_consumer_tag":null,
    "effective_policy_definition":[  

    ],
    "operator_policy":null,
    "policy":null,
    "consumer_utilisation":null,
    "idle_since":"2018-01-28 15:21:22",
    "memory":9640
},
...

看起来消息已被接受，但立即被丢弃且未记录。说到日志，rabbit 日志中也没有任何可疑之处。只是很多这样的:

2018-01-28 15:47:43.654 [info] <0.1417.0> accepting AMQP connection <0.1417.0> ([::1]:49058 -> [::1]:5672)
2018-01-28 15:47:43.696 [info] <0.1417.0> connection <0.1417.0> ([::1]:49058 -> [::1]:5672): user 'root' authenticated and granted access to vhost '/'
2018-01-28 15:47:43.742 [info] <0.1417.0> closing AMQP connection <0.1417.0> ([::1]:49058 -> [::1]:5672, vhost: '/', user: 'root')

为什么消息没有通过？

Answer 1

除了您将消息发送到错误的队列之外，您的代码看起来完全没问题。当您向不存在的队列发送消息时，RabbitMQ 将简单地丢弃该消息，因为它不知道将消息发送到哪里。

在您的代码中，您使用默认交换来发送消息。即:

$channel->basic_publish($msg, '', 'hello');

Here we use the default or nameless exchange: messages are routed to the queue with the name specified by routing_key, if it exists. The routing key is the third argument to basic_publish

https://www.rabbitmq.com/tutorials/tutorial-three-php.html

所以当你使用default exchange时，你必须指定routing key作为第三个参数，这是你的队列名称。当您使用默认交换时，RabbitMQ 会创建与队列同名的路由键。

要修复您的代码，只需将 hello 更改为您的队列名称，即 my_queue，它将开始发送和接收。

希望对您有所帮助:)