扩展Nextdoor的数据库：第一部分
At Nextdoor, the Core-Services team is responsible for the primary set of databases and caches that power the Nextdoor platform. This blog series explores our 2024 initiatives to enhance the scalability of this critical infrastructure. When we sat down at the whiteboard we sought to address two related problems:
在Nextdoor，核心服务团队负责支持Nextdoor平台的主要数据库和缓存。这系列博客探讨了我们在2024年的计划，以增强这一关键基础设施的可扩展性。当我们坐在白板前时，我们试图解决两个相关的问题：
- How can we reduce load on our primary database(s) and better utilize database read replicas?
- 我们如何减少对主数据库的负载，并更好地利用数据库读取副本？
- How can we improve our cache consistency?
- 我们如何改善缓存一致性？
In this post we’ll provide a primer on the common industry-wide solutions we’ve previously employed along with discussing their caveats and pitfalls. In subsequent posts we’ll dive into the technical details of the components of our solution and how they fit together.
在这篇文章中，我们将提供一个关于我们之前采用的行业普遍解决方案的入门介绍，并讨论它们的注意事项和陷阱。在后续的文章中，我们将深入探讨我们解决方案的组件的技术细节以及它们如何结合在一起。
Table of Contents
目录
Background
背景
Nextdoor’s backend, built using the Python-based Django web framework, powers the core product experience for neighbors, government agencies, and local businesses. The power of Django and similar frameworks (Rails, Spring, etc) is that they allow development teams to focus on implementing business logic rather than getting caught up in the details like learning and writing SQL.
Nextdoor的后端使用基于Python的Django网络框架构建，为邻居、政府机构和地方企业提供核心产品体验。Django和类似框架（Rails、Spring等）的优势在于，它们允许开发团队专注于实现业务逻辑，而不是陷入学习和编写SQL等细节中。
The Object Relational Mapping, ORMs, included in these frameworks provide a lever that allows developers to define data models and relationships between them in the application’s language without ever needing to worry about SQL.
这些框架中包含的对象关系映射（ORM）提供了一个杠杆，使开发人员能够在应用程序的语言中定义数据模型及其之间的关系，而无需担心 SQL。
As some readers are all too aware, relational data modeling comes at a cost. Without careful data modeling, performant access to relational data largely depends on that data residing on monolithic databases.
正如一些读者所熟知的，关系数据建模是有代价的。如果没有仔细的数据建模，对关系数据的高效访问在很大程...