<div class="output_wrapper" id="output_wrapper_id" style="font-size: 15px; color: rgb(62, 62, 62); line-height: 1.8; word-spacing: 2px; letter-spacing: 2px; font-family: 'Helvetica Neue', Helvetica, 'Hiragino Sans GB', 'Microsoft YaHei', Arial, sans-serif; background-image: linear-gradient(90deg, rgba(50, 0, 0, 0.05) 3%, rgba(0, 0, 0, 0) 3%), linear-gradient(360deg, rgba(50, 0, 0, 0.05) 3%, rgba(0, 0, 0, 0) 3%); background-size: 20px 20px; background-position: center center;"><h3 id="h1" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">1.主要做到以下两点:</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <ul style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: disc;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">尽量将请求过滤在上游。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">尽可能的利用缓存(大多数场景下都是查多于写)。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">如果流量巨大，导致各个层的压力都很大可以适当的加机器横向扩容。如果加不了机器那就只有放弃流量直接返回失败。快速失败非常重要，至少可以保证系统的可用性。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">业务分批执行：对于下单、付款等操作可以异步执行提高吞吐率。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">主要目的就是尽量少的请求直接访问到 DB。</p></li> </ul> <h3 id="h2" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">2. 架构图</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <figure style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px;"><img src="https://upload-images.jianshu.io/upload_images/11243907-f6c474b180af8713.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240" alt="image.png" title="image.png" style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; display: block; margin: 0px auto; max-width: 100%;"><figcaption style="line-height: inherit; margin: 0px; padding: 0px; margin-top: 10px; text-align: center; color: rgb(153, 153, 153); font-size: 0.7em;">image.png</figcaption></figure> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"></p> <ul style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: disc;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">前端请求进入 web 层，对应的代码就是 controller。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">之后将真正的库存校验、下单等请求发往 Service 层（其中 RPC 调用依然采用的 dubbo，只是更新为最新版本，本次不会过多讨论 dubbo 相关的细节，有兴趣的可以查看 <a href="https://crossoverjie.top/%2F2017%2F04%2F07%2FSSM11%2F" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; text-decoration: none; color: rgb(30, 107, 184); overflow-wrap: break-word;">基于dubbo的分布式架构</a>）。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">Service 层再对数据进行落地，下单完成</p></li> </ul> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">其实抛开秒杀这个场景来说正常的一个下单流程可以简单分为以下几步：</p> <ul style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: disc;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">校验库存</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">扣库存</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">创建订单</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">支付</p></li> </ul> <h3 id="h3" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">3.常见问题</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"><strong style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; font-weight: bold; color: rgb(233, 105, 0);">3.1 超卖现象（使用乐观锁更新）</strong></p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"><strong style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; font-weight: bold; color: rgb(233, 105, 0);">3.2 提高吞吐量</strong></p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">为了进一步提高秒杀时的吞吐量以及响应效率，这里的 web 和 Service 都进行了横向扩展。</p> <ul style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: disc;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">web 利用 Nginx 进行负载。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">Service 也是多台应用</p></li> </ul> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"><strong style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; font-weight: bold; color: rgb(233, 105, 0);">当并发量达到几百万时（分布式限流）</strong></p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">我们将并发控制在一个可控的范围之内，然后快速失败这样就能最大程度的保护系统。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"><strong style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; font-weight: bold; color: rgb(233, 105, 0);">3.3 sql查询太多（redis缓存）</strong></p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">这种数据我们完全可以放在内存中，效率比在数据库要高很多。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">由于我们的应用是分布式的，所以堆内缓存显然不合适，Redis 就非常适合。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">这次主要改造的是 Service 层：</p> <ul style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: disc;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">每次查询库存时走 Redis。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">扣库存时更新 Redis。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">需要提前将库存信息写入 Redis（手动或者程序自动都可以）。</p></li> </ul> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"><strong style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; font-weight: bold; color: rgb(233, 105, 0);">3.4请求同步转异步（kafka）</strong></p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">这里我们将写订单以及更新库存的操作进行异步化，利用 Kafka 来进行解耦和队列的作用。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">每当一个请求通过了限流到达了 Service 层通过了库存校验之后就将订单信息发给 Kafka ，这样一个请求就可以直接返回了。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">消费程序再对数据进行入库落地。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">因为异步了，所以最终需要采取回调或者是其他提醒的方式提醒用户购买完成。</p> <h3 id="h4" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">4. 总结</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">其实经过上面的一顿优化总结起来无非就是以下几点：</p> <ul style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: disc;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">尽量将请求拦截在上游。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">还可以根据 UID 进行限流。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">最大程度的减少请求落到 DB。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">多利用缓存。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">同步操作异步化。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">fail fast，尽早失败，保护应用。</p></li> </ul> <h3 id="h5" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">5、悲观锁</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">简单理解下悲观锁：当一个事务锁定了一些数据之后，只有当当前锁提交了事务，释放了锁，其他事务才能获得锁并执行操作。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">这里使用select for update的方式利用数据库开启了悲观锁，锁定了id=1的这条数据(注意:这里除非是使用了索引会启用行级锁，不然是会使用表锁，将整张表都锁住。)。之后使用commit提交事务并释放锁，这样下一个线程过来拿到的就是正确的数据。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">悲观锁一般是用于并发不是很高，并且不允许脏读等情况。但是对数据库资源消耗较大。</p> <h3 id="h6" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">6.乐观锁</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">那么有没有性能好，支持的并发也更多的方式呢？</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">那就是乐观锁。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">乐观锁是首先假设数据冲突很少，只有在数据提交修改的时候才进行校验，如果冲突了则不会进行更新。</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">通常的实现方式增加一个version字段，为每一条数据加上版本。每次更新的时候version+1，并且更新时候带上版本号</p> <h3 id="h" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">实践：基于分布式微服务的秒杀抢购功能的实现</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">借下图</p> <figure style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px;"><img src="https://upload-images.jianshu.io/upload_images/11243907-a72764011014c621.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240" alt="image.png" title="image.png" style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; display: block; margin: 0px auto; max-width: 100%;"><figcaption style="line-height: inherit; margin: 0px; padding: 0px; margin-top: 10px; text-align: center; color: rgb(153, 153, 153); font-size: 0.7em;">image.png</figcaption></figure> 乐优.png<p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"></p> <h3 id="h-1" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">秒杀设计到的微服务</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <ol style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: decimal;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">注册中心(Eurake) : @EnableEurekaServer开启注册中心，实现对各种微服务的集中管理</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">网关徽服务(zuul) : @EnableDiscoveryClient将服 务注册到到注册中心，@EnablezuulProxy开启 网关服务，对微服务路口做统一管理， 实现路由，降级(容错回退)，限流的功能。如果多台服务器，可以通过路径和服务的绑定path: /user-service/* ; serviceld: user-service2,实现负载均衡(默认是Ribbon轮询，还有随机)</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">用户中心微服务(user-service) :@EnableDiscoveryClient将 用户中心微服务注册到到注册中心，实现注册和登录功能</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">授权中心微服务(auth-service) : @EnableDiscoveryClient将用户中心微服务注册到到注册中心实现对登录的鉴权。</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">商品微服务(item-service) : @EnableDiscoveryClient将商品微服务注册到到注册中心，做商品的添加和查询。</p></li> </ol> <h3 id="h-2" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">具体秒杀流程逻辑</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <ol style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: decimal;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">网关对部分不需要登录认证的接口放行(要优化)1.注册用户，网关对注册放行</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">登录接口到网关，被路由到授权中心，授权中心微服务调用用户中心的登录接口进行校验，校验成功，利用JWT生成token,然后利用RSA非对称加密token,生成公钥和私钥保存，然后将token返回到客户端</p></li> </ol> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;"><strong style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; font-weight: bold; color: rgb(233, 105, 0);">秒杀业务</strong></p> <ol style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: decimal;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><span style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px;">在商品微服务中设置秒杀参数，根据参数的商品Id查询商品，构建商品秒杀表，添加，然后更新redis缓存</span></li> </ol> <pre style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px;"><code class="hljs javascript" style="overflow-wrap: break-word; margin: 0px 2px; line-height: 18px; font-size: 14px; font-weight: normal; word-spacing: 0px; letter-spacing: 0px; font-family: Consolas, Inconsolata, Courier, monospace; border-radius: 0px; color: rgb(169, 183, 198); background: rgb(40, 43, 46); overflow-x: auto; padding: 0.5em; white-space: pre !important; word-wrap: normal !important; word-break: normal !important; overflow: auto !important; display: -webkit-box !important;">BoundHashOperations<<span class="hljs-built_in" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; color: rgb(248, 35, 117); word-wrap: inherit !important; word-break: inherit !important;">String</span>, <span class="hljs-built_in" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; color: rgb(248, 35, 117); word-wrap: inherit !important; word-break: inherit !important;">Object</span>, <span class="hljs-built_in" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; color: rgb(248, 35, 117); word-wrap: inherit !important; word-break: inherit !important;">Object</span>> hashOperations = <span class="hljs-keyword" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; color: rgb(248, 35, 117); word-wrap: inherit !important; word-break: inherit !important;">this</span>.stringRedisTemplate.boundHashOps(KEY PREFIX);<br><br><span class="hljs-number" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; color: rgb(174, 135, 250); word-wrap: inherit !important; word-break: inherit !important;">1</span>/判断是否存在此K值<br><br><span class="hljs-keyword" style="font-size: inherit; line-height: inherit; margin: 0px; padding: 0px; color: rgb(248, 35, 117); word-wrap: inherit !important; word-break: inherit !important;">if</span> (hashOperations.hasKey(KEY PREFI){<br><br>hashOperations.delete(KEY_ PREFIX);<br><br>seckiloods.forEach(goods > hashOperatiosput(goos.getkud(.totring(), goods.getstock).totrin));))<br></code></pre> <ol start="2" style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: decimal;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">使用秒杀功能需要登录验证，创建登录拦截(LoginInterceptor extends HandlerinterceptorAdapter)对token进行验证，认证通过将用户信息存放到线程域中，并且走一个限流拦截AccessInterceptor extends HandlerinterceptorAdapter)实现限流功能</p></li> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">构建秒杀路径(限流)，加密，保存到redis缓存,隐藏秒杀路径，防止刷单。</p></li> </ol> <h3 id="h4-1" style="color: inherit; line-height: inherit; padding: 0px; margin: 1.6em 0px; font-weight: bold; border-bottom: 2px solid rgb(239, 112, 96); font-size: 1.3em;"><span style="font-size: inherit; line-height: inherit; margin: 0px; display: inline-block; font-weight: normal; background: rgb(239, 112, 96); color: rgb(255, 255, 255); padding: 3px 10px 1px; border-top-right-radius: 3px; border-top-left-radius: 3px; margin-right: 3px;">4. 秒杀</span><span style="display: inline-block; vertical-align: bottom; border-bottom: 36px solid rgb(239, 235, 233); border-right: 20px solid transparent;"> </span></h3> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">4.1. 验证秒杀路径</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">4.2. 读取库存， 减1后更新缓存</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">4.3. 库存不足直接返回“排队中”</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">4.4. 库存充足， 将商品信息封装入队MQ,然后直接返回“排队中”</p> <ol start="5" style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; padding-left: 32px; list-style-type: decimal;"> <li style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px; margin-bottom: 0.5em;"><span style="font-size: inherit; color: inherit; line-height: inherit; margin: 0px; padding: 0px;">然后订单微服务监听队列，消费队列，</span></li> </ol> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">5.1判断库存不足，将该商品设置成不可秒杀状态，</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">5.2查看是否秒杀到，秒杀到直接返回，</p> <p style="font-size: inherit; color: inherit; line-height: inherit; padding: 0px; margin: 1.7em 0px;">5.3没有秒杀到，创建订单</p></div>
来源：oschina
链接：https://my.oschina.net/u/4347889/blog/3346782