# 系统设计思路

模块划分

数据库选择/设计、API 设计

缓存设计、MQ 设计

稳定性：应用伸缩、数据分片/备份

高可用：限流、熔断、降级


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://gitbook.fantasticmao.cn/tech/fen-bu-shi-xi-tong/xi-tong-she-ji-si-lu.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.