NATO and the nations use distributed simulation environments for various purposes, such as training, mission rehearsal, and decision support in acquisition processes. Consequently, modeling and simulation (M&S) has become a critical technology for the coalition and its nations. Achieving interoperability between participating simulation systems and ensuring credibility of results currently often requires enormous effort with regards to time, personnel, and budget. Recent technical developments in the area of cloud computing technology and service oriented architecture (SOA) may offer opportunities to better utilize M&S capabilities in order to satisfy NATO critical needs. A new concept that includes service orientation and the provision of M&S applications via the as-a-service model of cloud computing may enable composable simulation environments that can be deployed rapidly and on-demand. This new concept is known as M&S as a Service (MSaaS). There has also been the recent emergence of containerization as an alternative to virtualization. Containerization is the process of creating, packaging, distributing, deploying, and executing applications in a lightweight and standardized process execution environment known as a container. Because containers are, in principle, lightweight, they are suitable to serve as the vehicle for the provision of packaged (micro)services. Service orientation is an approach to the design of heterogeneous, distributed systems in which solution logic is structured in the form of interoperating services. This paper investigates various aspects of service orientation and containerization including simulation composition, networking, discovery, scalability, and overall performance. This investigation provides background information on the topics of service orientation, containerization, and Docker – a technology ecosystem for working with containers. A case study is presented for the use of Docker in support of a training simulation based on the high level architecture (HLA). The HLA is an IEEE standard architecture for distributed simulation environments that was originally developed for defense applications. The case study introduces a number of training use cases, and shows how Docker can be used to assist in their implementation. The performance impact of running a simulation within container technology is also investigated. The application of container technology to HLA-based simulations as presented in this paper is novel. The motivation for looking at this topic stems from the activity being conducted within NATO MSG-136.
A software package for predicting design-flood hydrographs in small and ungauged basins