Microservice architecture is a trending topic in software design architecture and many enterprises adopted microservice design due its benefits and the rapid and wide deployment of cloud computing and as a result, many enterprises transformed their existing monolithic application to microservice to achieve business requirements as scaling up and agile development. In this paper we will guide software developers how to convert their existing monolithic application into microservice application without re-writing the whole microservice application from scratch, and we will also discuss the common issues that may face the software developer during the conversion processes. In addition to converting the business logic to microservice, we mention steps for converting the monolithic database into a database per service. Also, we summarize how Netflix and Airbnb converted their monolithic application to microservice application.

翻译：微服务架构是当前软件设计架构中的热门话题，诸多企业因微服务设计的优势以及云计算的快速广泛部署而采用该架构。因此，众多企业将其现有单体应用改造为微服务应用，以满足业务扩展和敏捷开发等需求。本文旨在指导软件开发者如何在不完全重写微服务应用的情况下，将现有单体应用转换为微服务应用，同时探讨转换过程中开发者可能面临的常见问题。除业务逻辑向微服务迁移外，本文还阐述了将单体数据库转换为"每服务独立数据库"的步骤。此外，我们总结了Netflix和Airbnb如何将其单体应用成功转型为微服务应用的经验。