Migrating An OSGi Legacy Project To The Cloud

Because of the popularity of the cloud, more and more developers hopes to move their projects to the cloud. For the most legacy projects, the business logic and the critical function may still play an important role, and creating a new project costs too much comparing to migrating an old one. So people will choose migrating a legacy project. In order to achieve the goal of low input high output, we have to find the best approach to migrate the legacy project, which is also the subject of this thesis.This thesis takes an OSGi legacy project as an example. At first, it introduces the status of current cloud migration, then come up with the four issues when migrating an legacy project to the PaaS:the compatibility between two platform, the standards of the private cloud, how to combine distributed nature with the OSGi data warehouse and the data consistency issue caused by the cache system. About the four issues, based on the actual needs of the real project, the later part of the thesis propose four solutions:Servlet Bridge, adding internal database support to the OSGi platform, centralized OSGi repository and the Ehcache+Terracotta. At last, this thesis describes the whole process of migrating this OSGi legacy projects to the cloud.