我有一个有趣的情况,我需要实现。我需要有一个EventMachine循环,该循环位于并等待AMQP队列中的消息,但随后中断该循环,以便定期向单独的AMQP队列发送消息。我是EventMachine的新手,这是我到目前为止所做的,除了EventMachine循环不发送必要的消息。
现在我做了两个过程:
listen_loop = Proc.new {
AMQP.start(connection_config) do |connection|
AMQP::Channel.new(connection) do |channel|
channel.queue("queue1", :exclusive => false, :durable => true) do |requests_queue|
requests_queue.once_declared do
consumer = AMQP::Consumer.new(channel, requests_queue).consume
consumer.on_delivery do |metadata, payload|
puts "[requests] Got a request #{metadata.message_id}. Sending a reply to #{metadata.reply_to}..."
response = "responding"
channel.default_exchange.publish(response,
:routing_key => metadata.reply_to,
:correlation_id => metadata.message_id,
:mandatory => true)
metadata.ack
end
end
end
end
end
Signal.trap("INT") { AMQP.stop { EM.stop } }
Signal.trap("TERM") { AMQP.stop { EM.stop } }
}
send_message = Proc.new {
AMQP.start(connection_config) do |connection|
channel = AMQP::Channel.new(connection)
queue = channel.queue('queue2')
channel.default_exchange.publish("hello world", :routing_key => queue.name)
EM.add_timer(0.5) do
connection.close do
EM.stop{ exit }
end
end
end
}
然后我有了EventMachine循环:
EM.run do
EM.add_periodic_timer(5) { send_message.call }
listen_loop.call
end
我能够在listen循环中接收消息,但是我无法定期发送任何消息。
答案 0 :(得分:0)
弄清楚我做错了什么。消息循环无法打开与RabbitMQ服务器的新连接,因为它已连接。将所有内容整合到一个EventMachine循环中并重用连接并且它可以正常工作。
对于那些好奇的人看起来像这样:
EM.run do
AMQP.start(connection_config) do |connection|
channel = AMQP::Channel.new(connection)
EM.add_periodic_timer(5) { channel.default_exchange.publish("foo", :routing_key => 'queue2') }
queue = channel.queue("queue1", :exclusive => false, :durable => true)
channel.prefetch(1)
queue.subscribe(:ack => true) do |metadata, payload|
puts "[requests] Got a request #{metadata.message_id}. Sending a reply to #{metadata.reply_to}..."
response = "bar"
channel.default_exchange.publish(response,
:routing_key => metadata.reply_to,
:correlation_id => metadata.message_id,
:mandatory => true)
metadata.ack
end
end
Signal.trap("INT") { AMQP.stop { EM.stop } }
Signal.trap("TERM") { AMQP.stop { EM.stop } }
end