How to design a high concurrency system?

1. System split Split the system into several subsystems , Each system is connected to a database

2. cache Most scenes are more reading and less writing , Read a lot of cache , Write database

3. MQ Write when the pressure is too high , Backlog write requests in mq in , Relieve database pressure

4. Sub database and sub table When the database processing capacity is insufficient Can't handle it mq The data of the  

5. Database read write separation Use when reading request pressure is too high