SecKill Develop Journey (II)

Previous article We only built a core function seckill demo, this article we will gradually improve more features in order to let it had complete function.

Problems

Review what we has been done, we can find that:

1. Service for Promotion entity is not provided (inject by Spring);
2. Lack some base check and features, include:
   • One customer can only grab one coupon per promotion
   • Support multi promotion activing (discount of each promotion is different)
3. If Command micro-service down, it will recovery all uncompleted promotions immediately before start-up again.

Maybe you would say that customer management and customer login function are not listed? Indeed, the customer is indispensable in our scenario, in order to simply design, we don’t include login and token authentication etc., if you are interesting about this, you can see ServiceComb’s Company demo application to get more information.

Improvement Design

For entity, domain-driven design (DDD) recommended to use a separate interface, so we design a new Admin micro-service to provide service:

Improvement Implement

Implement of Admin micro-service

Admin micro-service only provide services for promotion entity, we can map this function to REST method:

• New promotion map to Post;
• Modify promotion map to Put; 　　
• Query promotion map to Get; 　　

• Delete promotion map to Delete.　　

  To match current requirement we only need implement Post and Get, In addition, already started promotion should not be able to modify, so we increased the corresponding check.

New check and features Implement

Add a HashSet per promotion to check whether customer had grab coupon;
Add “SecKillPromotionBootstrap” class as promotion bootstrap manager for support multi active, “SecKillCommandService” and “SecKillPersistentRunner” now managed(create) by it。

Command micro-service auto recovery Implement

Add “SecKillRecoveryService” class to check state of promotion, uncomplement promotions whether unstart or activing all need check by it to init start-up information including left coupons, grabbed customers list, etc.

Function Verification

Finally, we use PostMan to check completed functions, Please ensure request body fill with JSON format, and set Content-Type to application/json：

Create Promotion

Query Activing Promotions

Reject duplicate Grab