Abstract—Dynamic software updating research efforts have mostly been focused on updating application code and in-memory state. As more and more applications use embedded databases for storage, dynamic updating solutions will have to support changes to embedded database schemas. The first step towards supporting dynamic updates to embedded database schemas is understanding how these schemas change—so far, schema evolution studies have focused on large, enterpriseclass databases. In this paper we propose an approach for automatically extracting embedded schemas from regular applications, e.g., written in C and C++, and automatically computing how schemas change as applications evolve. To showcase our approach, we perform a long-term schema evolution study on four popular open source programs that use embedded databases: Firefox, Monotone, BiblioteQ and Vienna. Our study spans 18 cumulative years of schema evolution and reveals that change patterns and frequency in embedded databases differ from schema changes in enterprise-class databases that formed the object of prior studies. Our platform can be used for performing long-term, large-scale embedded schema evolution studies that are potentially beneficial to dynamic updating and schema evolution researchers. I.

The fast evolution pace for cloud computing software is on a collision course with our growing reliance on cloud computing. On one hand, cloud software must have the agility to evolve rapidly, in order to remain competitive; on the other hand, more and more critical services become dependent on the cloud and demand high availability through firm Service Level Agreements (SLAs) for cloud infrastructures. This race between the needs to increase both the cloud upgrade frequency and the service availability is unsustainable. In this paper we highlight challenges and opportunities for upgrades in the cloud. We survey the release histories of several cloud applications to analyze their evolution pace, and we discuss the shortcomings with current cloud upgrade mechanisms. We outline several solutions for sustaining this evolution while improving availability, by focusing on the novel characteristics of cloud computing. By discussing several promising directions for realizing this vision, we propose a research agenda for the future of software upgrades in the cloud. 1.