Why is ODIN ported to Rust

As of 12/2023 we have started to port the ODIN server infrastructure to Rust. This became necessary because our focus has shifted from RACEs original goal of building a Java-based prototyping environment for distributed simulations to ODINs goal of supporting field-deployable production servers that also utilize external native libraries and applications. In other words ODIN (as an application domain) is now the focus, not the underlying library to implement it. The main design principle stays the same: using actors to create scalable concurrent systems.

Although RACE was cross-platform (because of its pure Java use) it was originally supposed to run on dedicated machines with respective admin support. Installation requires to build from sources, which means there are several prerequisites (recent JDK version, Git, SBT build system, local RACE repository clone).

ODIN servers on the other hand will have to run on machines that do not require build-from-source installation and might not have the computational resources of a Java production server. ODIN applications also make use of existing external native software, i.e. they are not pure Java. This means the original build-from-source / all-batteries-included approach of RACE is not applicable anymore.

There are additional reasons for porting ODIN. RACE was heavily based on the excellent Akka library for its actor system implementation. As of 09/2022 Lightbend - the owner of Akka - has moved from Apache to a proprietary license. While ODIN as an open source project could have been exempt the same is not necessarily true for ODIN's user community, which includes companies and universities. For this reason ODIN got stuck with Akka < 2.7, which means there also was a delay in critical patches.

Lastly, RACE was using Scala 2.3. In order to stay abreast with latest versions of major dependencies we would have had to port RACE to Scala 3. For all these reasons change was inevitable.

Our solution is twofold:

(1) port to a native programming environment with good cross-platform support and a rich eco-system for server implementation. Rust has proven itself as a very suitable choice. The capability to produce single file, statically linked applications that can safely use the huge eco-system of Rust crates and incorporate native C/C++ libraries is invaluable. We can also significantly reduce runtime cost (both memory and CPU) of ODIN applications.

(2) move functions that are not easy to build for/run on ODIN stakeholder machines to dedicated Rust-based edge servers that make use of the same infrastructure we create for (1). This means we build new edge servers that replace external ones such as dump1090 (for ADS-B tracking), and add new ones for functions that are more ODIN specific (e.g. for WindNinja micro grid wind integration), all from the same programming environment/build system. These servers will enjoy the same easy deployment we gain from (1).

This porting effort is now well under way and sources are gradually showing up in the RACE repository. We expect to have first examples around 03/2024. Please contact peter.c.mehlitz@nasa.gov if you have questions regarding the ODIN Rust version.