Comparison of message middleware such as Kafka, RabbitMQ, RocketMQ, etc. - Message transmission performance and difference

... Distributed system, we widely use message middleware to exchange data between systems, which is convenient for asynchronous decoupling. Now there are a lot of open source news middleware. Some time ago, our own product RocketMQ (MetaQ kernel) is also open source and get everyone's...


Big data interview questions and answers (1)

... kafka's message includes information A Kafka message consists of a fixed-length header and a variable-length message body. header One byte of magic (file format) and four bytes of CRC32 (used to determine whether the body message body is normal). When the value of magic is 1, there will...


MySql entry statement (2)

... 1. 建表 create table Student ( ID int, Name varchar(20), Age int ); 2.增 insert into Student values(1,"April",21); insert into Student values(2,"Harris",22); insert into Student values(3,"Dave",19); 3. Delete delete from Student where Name='Dave'; Delete Name=“Dave” line. If there is no...


Celery Notes 1 (Quick Start)

... In an application service, for business scenarios where timeliness requirements are not so high, we don't have to wait until all tasks have been executed before returning results, such as user registration scenarios, saving user accounts. After the password, it can be returned...


The three solutions for distributed locks

... lock must be manually released. Multiple JVMs can't be solved on a single JVM. Distributed lock: 1. Based on the database solution. Innodb supports line lock implementation: 测试: Look at the database every 10s, the efficiency is not high. A blocking lock that cannot be implemented...


Small program to get WeChat login user

... Traditional small program WeChat login 小程序Use cloud development WeChat login 云开发 can automatically realize user login verification, developers do not need to verify user identity again The user information can be obtained directly through the cloud function event.userInfo.openId. When...


Mongodb storage operation and additions and deletions change

... Download MongoDB's URL http://www.runoob.com/mongodb/mongodb-window-install.html Open mongodb method, which is downloaded and installed The directory has a file bin into it and runs as an administrator. Pymongo is a package that operates mongodb. It can be downloaded from the...


Keke921231's column

... 1. Install node.js https://nodejs.org/en/download/. 2.cmd Go to the project file directory and run npm install 3. Have the node_modules folder in the directory, run the index.js file port in the config directory of the npm run dev 4.masterBack project: corresponding to the front-end...


Redis non-relational database use

... modify configuration file (find redis.red.windows.conf under redis to modify the main configuration file Search bind, change the following ip to the current server ip 2. Modify the configuration file from the search for slaveof, uncomment the code, and then add the ip and port number....


Static webpages and dynamic webpages

... static webpages and dynamic webpages 一, static webpages: Visitors can only passively access webpage content provided by website builders; static webpage features : 1. The content of the webpage will not change unless the web designer modifies the content of the webpage; 2. The...