> For the complete documentation index, see [llms.txt](https://longxingtan.gitbook.io/mle-interview/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://longxingtan.gitbook.io/mle-interview/03_system/02_system/log_system.md).

# 日志系统

> a distributed data store for logs

## 1. requirements

* 要求能够将PII信息隐藏，能够做top k exceptions，能够做快速查询，比如按各种不同的fi
* Our goal is to build a real-time aggregation system. WebServer logs event to our system using the following function call: log(ad\_id, user\_id, event\_type).\
  At this moment we plan to have only 2 types of events: "ad was shown" and "ad was clicked on".

## 参考

* <https://engineering.fb.com/2017/08/31/core-data/logdevice-a-distributed-data-store-for-logs/>