RabbitMQ在运行时，偶尔会有一些死信，即消息未正常消费，造成消息积压在消息队列中， 一直卡住，重复循环消费原来的消息队列
那么就需要有一种机制，来查看RabbitMQ是否有消息未正常消费，从而让RabbitMQ消费端重新启动服务，让消息能顺利消费（例如让Windows Service重启等）
首先，查看RabbitMQ Manage的界面，可以看到，这里未应答的消息总数是0，在某些特定的情况下，有可能会出现未应答的消息的，所以需要进行检测
RabbitMQ Management API文档地址：https://pulse.mozilla.org/api/
我们这里使用的API是/api/queues/vhost/name
请记住，其中vhost参数使用提默认的 / ，需要Encoding为%2F
Postman中如下
权限部分使用Basic Auth，并输入RabbitMQ Management的用户名和密码
返回的JSON如下
{ "consumer_details": [], "arguments": {}, "auto_delete": false, "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", 16384, 57, 0, 98304 ], "len": 61, "mode": "default", "next_seq_id": 98304, "q1": 0, "q2": 0, "q3": 3, "q4": 1, "target_ram_count": "infinity" }, "consumer_utilisation": null, "consumers": 0, "deliveries": [], "durable": true, "effective_policy_definition": {}, "exclusive": false, "exclusive_consumer_tag": null, "garbage_collection": { "fullsweep_after": 65535, "max_heap_size": 0, "min_bin_vheap_size": 46422, "min_heap_size": 233, "minor_gcs": 19 }, "head_message_timestamp": null, "idle_since": "2019-11-04 8:57:13", "incoming": [], "memory": 30772, "message_bytes": 20576, "message_bytes_paged_out": 0, "message_bytes_persistent": 20576, "message_bytes_ram": 1247, "message_bytes_ready": 20576, "message_bytes_unacknowledged": 0, "messages": 61, "messages_details": { "rate": 0.0 }, "messages_paged_out": 0, "messages_persistent": 61, "messages_ram": 4, "messages_ready": 61, "messages_ready_details": { "rate": 0.0 }, "messages_ready_ram": 4, "messages_unacknowledged": 0, "messages_unacknowledged_details": { "rate": 0.0 }, "messages_unacknowledged_ram": 0, "name": "SyncData.5c8f2d5c806f0b43fc4a7a5c", "node": "rabbit@rabbit", "operator_policy": null, "policy": null, "recoverable_slaves": null, "reductions": 107151, "reductions_details": { "rate": 0.0 }, "single_active_consumer_tag": null, "state": "running", "type": "classic", "vhost": "/" }
其中Ready和Unacked的消息如下