AnnaBellaDB: a key value store for stateless network functions

ABSTRACTThe cloud-native paradigm has become a widely applied approach to ensure elasticity and reliability of applications running in the cloud. One recurrent motif is the stateless design of applications, which aims to decouple the life-cycle of application states from the life-cycle of individual application instances. Application data is written to and read from cloud databases, deployed close to the application code to ensure low latency bounds on state access. When applying a stateless design, the performance of the cloud service is often limited by the cloud database. In order not to become a bottleneck, database instances are distributed on multiple hosts, and strive to ensure data locality for all application instances. However, the shared nature of certain states, and the inevitable dynamics of the application workload necessarily lead to inter-host data access within the data center or even across data centers and edge servers, if the service is geographically distributed. To minimize the service performance loss due to the stateless design of applications, we propose a latency and access pattern aware state storage design and adapt it to Anna, a key-value store from academia to showcase a proof-of-concept that is ideal to store network function states. To foster further research in this area, we make our solution open-source.