消息隊列-RabbitMQ

Broker: 接收和分發(fā)消息的應(yīng)用，RabbitMQ Server 就是 Message Broker
Virtual host: 出于多租戶和安全因素設(shè)計的，把 AMQP 的基本組件劃分到一個虛擬的分組中，類似于網(wǎng)絡(luò)中的 namespace 概念，當(dāng)多個不同的用戶使用同一個RabbitMQ server 提供的服務(wù)時，可以劃分出多個 vhost，每個用戶在自己的 vhost創(chuàng)建 exchange／queue 等。
Connection: publisher／consumer 和 broker 之間的 TCP 連接。 
Channel: 如果每一次訪問 RabbitMQ 都建立一個 Connection，在消息量大的時候建立 TCP Connection 的開銷將是巨大的，效率也較低。Channel 是在 connection內(nèi)部建立的邏輯連接，如果應(yīng)用程序支持多線程，通常每個 thread 創(chuàng)建單獨的channel 進行通訊，AMQP method 包含了 channel id 幫助客戶端和 message broker識別 channel，
所以 channel 之間是完全隔離的。Channel 作為輕量級的 Connection極大減少了操作系統(tǒng)建立 TCP connection 的開銷。
Exchange: message 到達 broker 的第一站，根據(jù)分發(fā)規(guī)則，匹配查詢表中的 routing key，分發(fā)消息到 queue 中去。常用的類型有：direct (point-to-point), topic (publish
subscribe) and fanout (multicast)。 
Queue: 消息最終被送到這里等待 consumer 取走。 
Binding: exchange 和 queue 之間的虛擬連接，binding 中可以包含 routing key。Binding 信息被保存到 exchange 中的查詢表中，用于 message 的分發(fā)依據(jù)。 

#vim /usr/lib/rabbitmq/lib/rabbitmq_server-3.8.3/ebin/rabbit.app
39   {loopback_users, []},  #刪除被禁止登陸的 guest 賬戶 
# systemctl restart rabbitmq-server.service #重啟 rabbitmq 服務(wù) 

192.168.134.192 rabbitmq-server-1
192.168.134.193 rabbitmq-server-2
192.168.134.194 rabbitmq-server-3

sudo apt-get update -y

## Install prerequisites
sudo apt-get install curl gnupg -y

## Install RabbitMQ signing key
curl -fsSL https://github.com/rabbitmq/signing-keys/releases/download/2.0/rabbitmq-release-signing-key.asc | sudo apt-key add -

## Install apt HTTPS transport
sudo apt-get install apt-transport-https

## Add Bintray repositories that provision latest RabbitMQ and Erlang 21.x releases
sudo tee /etc/apt/sources.list.d/bintray.rabbitmq.list <<EOF
## Installs the latest Erlang 22.x release.
## Change component to "erlang-21.x" to install the latest 21.x version.
## "bionic" as distribution name should work for any later Ubuntu or Debian release.
## See the release to distribution mapping table in RabbitMQ doc guides to learn more.
deb https://dl.bintray.com/rabbitmq-erlang/debian bionic erlang
deb https://dl.bintray.com/rabbitmq/debian bionic main
EOF

## Update package indices
sudo apt-get update -y

## Install rabbitmq-server and its dependencies
sudo apt-get install rabbitmq-server -y --fix-missing

scp /var/lib/rabbitmq/.erlang.cookie 192.168.134.193:/var/lib/rabbitmq/.erlang.cookie
scp /var/lib/rabbitmq/.erlang.cookie 192.168.134.194:/var/lib/rabbitmq/.erlang.cookie

# vim /usr/lib/rabbitmq/lib/rabbitmq_server-3.7.22/ebin/rabbit.app 
39   {loopback_users, []},  #刪除被禁止登陸的 guest 賬戶 
# systemctl restart rabbitmq-server.service #重啟 rabbitmq 服務(wù) 

rabbitmqctl  stop_app    #停止 app 服務(wù) 
rabbitmqctl   reset      #清空元數(shù)據(jù) 
#將rabbitmq-server-1 添加到集群當(dāng)中，并成為內(nèi)存節(jié)點，不加--ram 默認(rèn)是磁盤節(jié)點
root@rabbitmq-server-1:~#  rabbitmqctl  join_cluster rabbit@rabbitmq-server-3 --ram 
Clustering node rabbit@rabbitmq-server-1 with rabbit@rabbitmq-server-3
rabbitmqctl  start_app   #啟動 app 服務(wù) 

root@rabbitmq-server-2:~#  rabbitmqctl  stop_app 
Stopping rabbit application on node rabbit@rabbitmq-server-2 ...
root@rabbitmq-server-2:~# rabbitmqctl  reset 
Resetting node rabbit@rabbitmq-server-2 ...
root@rabbitmq-server-2:~# rabbitmqctl  join_cluster rabbit@rabbitmq-server-3 --ram
Clustering node rabbit@rabbitmq-server-2 with rabbit@rabbitmq-server-3
root@rabbitmq-server-2:~# rabbitmqctl  start_app 
Starting node rabbit@rabbitmq-server-2 ...
 completed with 3 plugins.

root@rabbitmq-server-1:~#  rabbitmqctl set_policy  ha-all "#"  '{"ha-mode":"all"}' 

rabbitmqctl  add_vhost xxx   #創(chuàng)建 vhost
rabbitmqctl  list_vhosts   #列出所有 vhost 
rabbitmqctl  list_queues   #列出所有隊列 
rabbitmqctl  add_user jack 123456   #添加賬戶 jack 密碼為 123456 
rabbitmqctl  change_password jack 654321  Changing   #更改用戶密碼 

import subprocess

running_list = []
error_list = []
false = "false"
true = "true"


def get_status():
    obj = subprocess.Popen(("curl -s -u guest:guest  http://localhost:15672/api/nodes &> /dev/null"), shell=True,
                           stdout=subprocess.PIPE)
    data = obj.stdout.read()
    data1 = eval(data)
    #print(data1)
    for i in data1:
        if i.get("running") == "true":
            running_list.append(i.get("name"))
        else:
            error_list.append(i.get("name"))


def count_server():
    if len(running_list) < 3:  # 可以判斷錯誤列表大于0或者運行列表小于3，3未總計的節(jié)點數(shù)量
        print(100)  # 100就是集群內(nèi)有節(jié)點運行不正常了
    else:
        print(50)  # 50為所有節(jié)點全部運行正常


def main():
    get_status()
    count_server()


if __name__ == "__main__":
    main()