Linux server development, redis protocol and asynchronous mode

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1.redis The network layer of

single reactor Model

2.redis Of pipeline

redis It's a request response .pipeline Is a client behavior , It can send multiple commands at once , Back together , At least one round-trip time is saved .
lua Multiple statements can be written in a script , And you can have your own logic ,lua The form ability of is relatively strong and atomic . because lua A script is just a command ,redis A single thread , So nature has atomicity .

client script load xxx.lua Send to server , Generate 40 Bit string as a flag script , Reduce network transmission

• A： When you reach a certain state, you can return to the original state .redis It's not atomic , Rollback is not supported .
• C： Constraints are to remain intact ,redis There is no consistency in the traditional sense , For example, add money and reduce money , There are successes and failures .
• I： Single thread execution , All have isolation .
• D： Four persistence strategies .redis It's persistent .

3.redis The business of multi exec lua

adopt MULTI and EXEC The command defines the scope of the transaction . adopt wacth Command lock key, If key Automatically cancel the transaction when changes occur . Usually use lua Scripts handle transactions . It's not transactional , Atomicity , The main goal is to reduce the time of network transmission .

4.redis pub/sub

5. Asynchronous connection

skynet Adopt asynchronous connection .

Four aspects to be realized in the future

• Single threaded reactor
• Multithreading reactor, One in charge listen,8 Threads are responsible for operating the network IO
• Ctrip eliminates callback ,go Language understanding is more profound
• Implement a third-party agreement ,redis,MySql,etcd