Now that edge devices with embedded inference support are starting to appear, there’s a need for scalable deployment of software and configuration data to these devices. rt-ai can address this scaling requirement using synth modules. Synth modules are composite elements in a stream processing network (SPN) that combine simpler stream processing elements (SPEs) into more complex structures. The idea is that a synth module can be created that contains the SPEs required for a specific type of embedded edge inference device. This synth module can then be deployed, configured and managed for all instances of this type of edge inference device very easily using the rtaiDesigner tool.
The screen capture above is an example of the output from an SPN that includes two differently configured DeepLab v3+ instances along with associated video and audio capture SPEs. The top level SPN looks like this:
As with standard SPEs, synth modules can be allocated to any node in the rt-ai Edge network. The only limitation at present is that all SPEs in an instance of a synth module must run on the same node. This will be relaxed at later date when automatic SPE placement based on available resources is implemented. A synth module can be instanced multiple times on the same node or different nodes as required. In this example, two instances of the same synth module were placed on the Default node.
Individual instances of a synth module can be configured in the top level design:
In this case, Synth0 is being configured. Note the tabs in the dialog. There is one tab for each SPE in the underlying synth module. SPE dialogs are auto-generated from a JSON spec in the SPE design directory. This makes it very easy to construct a combined dialog when SPEs are used in a synth module. Any design can be turned into a synth module just by pressing the Generate synth module button. The synth module then becomes available in the Add module dialog just like any other SPE.
As designs are completely regenerated every time the Generate design button is pressed, internal changes can be made to the synth module at any time and they will be reflected in top level designs the next time that they are generated.
Right now, synth module designs cannot include synth modules, only standard SPEs. If multi-level synth modules were required, it would be a small extension of the current implementation. For now, the ability to reproduce and configure a standard SPN subnetwork multiple times is sufficient to scale most edge inference applications.