Edge modes
Edges in a federation are in one of three possible modes - INTERACTIVE, ONLINE, or AUTONOMOUS. The modes indicate to what extent the edges interacts with the server.
| Mode | Interactivity | Edge queries | Creation |
|---|---|---|---|
| INTERACTIVE | Have an uplink to the server. Edge state can be set from the server, which will trigger a poll from the edge. | Possible to send continous queries from the server and see the results. | Default mode for edges. |
| ONLINE | Has no uplink, but polls the server at regular intervals. Edge state can be set from the server, the request will await next poll. | Runs models and queries independently. To store the results and send to the server when connecting, use Store and Forward. | Set an edge to online explicitly. |
| AUTONOMOUS | Not reachable from the server at all, managed individually. | No, only runs models started at the edge. | Start the SA Engine instance at the edge in autonomous mode. |
Viewing and changing edge mode
All edges have a specific state which includes the edge mode. It also shows which models are loaded and the last load errors.
To get the state of an edge, call
edge:actual_state("EDGE_NAME");
This will return a record that specifies the edge mode, loaded models and load errors, for example
{"models:loaded":[],"last_load_errors":[],"edge_mode":'INTERACTIVE'}
To set the mode of an edge, use edge:set_mode, for example this query will set the mode of "edge_name" to ONLINE.
edge:set_mode("edge_name", "ONLINE");
It is convenient to use interactive edges while developing models. For large fleets in production, it is advisable to use online mode to limit the load on the server.