The thought of the second-kill concurrency in the Redis Realization Mall

The full code is too long, here's a thought.

1: Before the start of the kill activity, the SKU and inventory of the item are credited to Redis

Redistemplate.expire (sku,25,timeunit.hours of goods); Cache 24 hours with the unique identity of the product as key

2: Add a counter to the product order method, the commodity SKU is key, the counter is atomic, there is no concurrency problem

Long Count = Redistemplate.opsforvalue (). Increment (commodity suk, 1);

3: When the order is submitted, the inventory of the SKU is obtained from Redis, and the count comparison in the counter, if it is greater than or equal to count, indicates that the seconds are dead

4: Synchronizing inventory to the database

If you do not know how to install Redis, you can refer to the previous article