6-1 The role and environment of RocketMq message queue

1 RocketMq message queue function

1 异步解耦：不需要即时同步，如用户注册后的短信邮件通知，通知消息异步处理
2 流量削峰：如秒杀业务的消息通知，通知消息异步处理

Other queues: activeMq, kafka slightly;

2 Build a simple rmq environment under the centos of vm

Requirements: Linux system x64, jdk8+

2.1 Download the installation packagehttp://rocketmq.apache.org/release_notes/release-notes-4.4.0/

2.2 Installation, upload to /usr/local/src,

• 1 Enter the compressed file directory: cd /usr/lcoal/src
• 2 Unzip the file: unzip xxx.zip
  • If there is no decompression command, please install it first: yum install zip unzip
• 3 Move the decompressed folder: mv rocketmq-xxxx /usr/local/rocketmq

2.3 Start nameServer and broker

• 1 Enter the startup directory:cd /usr/local/rocketmq/bin
• 2 Start nameServer: nohup ./mqnamesrv &
• 3 Test:tail -f ~/logs/rokectmqlogs/namesrv.log
  • Display The Name Server boot successindicates success
• 4 Test port: netstat -an | grep 9876
  • If there is no netstat command, please install it first: yum install net-tools
  • Port exists, indicating success

2.4 Start the broker

• 1 Edit bin/runbroker.sh, bin/runserver.sh, modify the value of parameter JAVA_OPT -Xms256m -Xmx256m -Xmn128m
• 2 Startnohup ./mqbroker -n localhost:9876 &
• 3 testtail -f ~/logs/rocketmqlogs/broker.log
  • Show boot success means success

2.4 Testing

• 1 Open two windows, one for sending and one for receiving, and enter the bin directory
• 2 Send the command:

export NAMESRV_ADDR=localhost:9876 
./tools.sh org.apache.rocketmq.example.quickstart.Producer

• 3 Receive commands:

export NAMESRV_ADDR=localhost:9876 
./tools.sh org.apache.rocketmq.example.quickstart.Consumer

• 4 After receiving it, it has been monitoring the state. If you execute the transmission again, you can find that the receiving window receives the second time

2.5 Close mq

./mqshutdown broker 
./mqshutdown namesrv

3 rocketMq console installation

• 1 Download https://github.com/apache/rocketmq-externals/releases, select console to download
• 2 Modify the startup class rocketmq-console\src\main\resources\application.properties

server.port=7777
rocketmq.config.namesrvAddr=192.168.149.11:9876

• 3 Compile the jar package and executemvn clean package -Dmaven.test.skip=true
• 4 Upload to vm's /usr/local/src, startjava -jar r-xx.jar
• 5 Test, browser accesshttp://192.168.149.11:7777