在PHP中掩盖信用卡号码(Mask credit card number in PHP)

 
 
 如果我们的架构可能有任何设计缺陷。 
 
 
 好吧，请记住，从通用图表中我们无法说清楚。 但这里有一些注意事项： 
 
 1）MongoDB不像其他数据库（如DynamoDB，Riak或Cassandra）那样容易扩展。 例如，如果您超过单个主服务器的容量（无论您拥有多少个从属服务器，所有写入服务都转到单个主服务器），您将不得不进行分片。 但是切换到分片是非常具有破坏性的，并且设置起来非常繁琐。 
 
 如果你不希望超过一个节点的写入容量，那么你就可以在MongoDB上运行了。 
 
 2）您将如何处理异步任务，例如发送电子邮件，创建长报告等？ 
 
 可以在请求循环中执行这些操作，这可能是一个很好的入门方法。 但是当你有更多的盒子时，失败的可能性就会增加。 当一个盒子死掉时，所有的异步任务都会消失，没有人会知道它们是什么。 你也可能遇到一个问题，即一个盒子负载过重的异步任务（使用太多的CPU或内存），并且问题会变得越来越糟，因为它会获得更多任务并且更慢地完成它们。 
 
 此外，像ELB这样的前端将有60秒的限制，如果您的某些请求可能需要更长时间，这可能会导致问题。 （通过轮询或其他东西将它们转移到异步作业中。） 
 
 3）ELB不支持Web套接字。 考虑一下，如果您认为自己可能需要使用websockets。 

 
 
if our architecture might have any design flaws.
 
 
Well, keep in mind that we can't tell much from a generic diagram. But here are some notes:
 
1) MongoDB isn't as easy to scale as other databases such as DynamoDB, Riak or Cassandra. For example, if you ever exceed the capacity of a single master (no matter how many slaves you have, all writes go to the single master), you'll have to shard. But switching to sharding is very disruptive and very tedious to set up.
 
If you don't expect to exceed the write capacity of one node, then you'll be fine on MongoDB.
 
2) What will you do for async tasks such as sending emails, creating long reports, etc?
 
It's possible to do these things in the request loop, and that's probably a fine way to get started. But as you have more boxes, the chances of failure go up. When a box dies, all the async tasks go away and nobody will know what they were. You also can have problems where one box gets heavily loaded with async tasks (using too much CPU or memory), and the problem will get worse and worse as it gets more tasks and completes them more slowly.
 
Also, a front-end like ELB will have a 60-second limit, which can cause problems if some of your requests could take longer. (Spin them off into async jobs with polling or something.)
 
3) ELB doesn't support web sockets. Consider that if you think you might want websockets down the road.