### 单体架构的优点 In the early days of FTGO, when the application was relatively small, the application’s monolithic architecture had lots of benefits: * Simple to develop—IDEs and other developer tools are focused on building a single application. * Easy to make radical【快速】 changes to the application—You can change the code and the database schema, build, and deploy. * Straightforward【直接的】 to test—The developers wrote end-to-end tests that launched the application, invoked the REST API, and tested the UI with Selenium. * Straightforward to deploy—All a developer had to do was copy the WAR file to a server that had Tomcat installed. * Easy to scale【扩展】—FTGO ran multiple instances of the application behind a load balancer. Over time, though, development, testing, deployment, and scaling became much more difficult. Let’s look at why.