idk

[!tldr] This explains why for the given task RESTful is better than gRPC (not relavant but good to know)

You make an excellent point. I was assuming you wanted a "Mission Control" style live map.

If your architecture is truly "Fire and Forget" (the server gives a task, and the client executes it onafhankelijk / independently), then you likely do not need gRPC.

In fact, forcing a constant verbinding (connection) for a "start-stop" system is bad engineering. It adds complexity where none is needed.

Here is the breakdown of why you should probably switch to a simpler architecture, and the one specific risk you need to cover.

1. Why "Start-Stop" kills the need for gRPC

In a "Start-Stop" model, the telescope is not a drone being flown by a pilot; it is a delivery driver picking up a package.

• The Workflow:

  1. Poll: Client wakes up and asks via HTTP GET: "Do you have work for me?"

  2. Task: Server responds: "Yes, Image M42, 30x60s exposures."

  3. Disconnect: Client goes offline (logically), slews the mount, takes images, and handles its own guiding/focusing loop.

  4. Report: Client uploads the resulting FITS file via HTTP POST.

• The Verdict: This is a classic RESTful state machine. You do not need streaming. You do not need binary packets. You just need a simple Todo list API.

2. The Pros of Dropping gRPC

If you move to a standard REST API (using standard Go net/http handlers), you solve most of the problems I warned you about:

• No "Zombie" Connections: Since there is no persistent connection, there is no risk of the server thinking a dead client is alive.

• Easy Debugging: You can see exactly what the client is doing by looking at the Apache/Nginx access logs (GET /jobs/next).

• Resilience: If your server crashes and restarts while the telescope is imaging, the telescope doesn't care. It is onafhankelijk (independent). It just retries the upload later.

3. The Only Risk: The "Abort" Latency

There is one major downside to "Start-Stop" that you must design around: Reaction Time.

• Scenario: You issue a 2-hour job to image a star. 10 minutes later, a Gamma Ray Burst (GRB) happens, and you want all telescopes to stop immediately and point to the new target.

• The Problem: In a Start-Stop model, the telescope is "deaf" until it finishes its 2-hour job and checks in again. You cannot interrupt it.

• The Solution (Without gRPC):

  • The "Heartbeat" Poll: Even while imaging, the client sends a tiny HTTP request every 30 seconds: GET /status.

  • The Response: The server usually sends 200 OK. If an emergency happens, it sends 205 Reset Content, which triggers the client's "Abort" logic.

4. Technical Recommendation: The "Job Queue" Architecture

Since you are using Go, this is the cleanest way to build your backend. Do not build a "Controller"; build a Dispatcher.

The Database Schema (PostgreSQL):

• Jobs Table: ID, TargetRA, TargetDec, Status (Pending, Assigned, Completed), AssignedTo.

The Go Implementation (Pseudocode):

Go

// Client (The Telescope)
func main() {
    for {
        // 1. Ask for work
        job := getNextJob() // HTTP GET

        if job == nil {
            time.Sleep(1 * time.Minute) // Wait if no work
            continue
        }

        // 2. Do the work independently
        // The client handles all hardware logic here
        result := executeImagingRun(job)

        // 3. Upload result
        uploadData(result) // HTTP POST
    }
}

5. Final Decision Check

• Do you need to manually joystick a telescope remotely? (e.g., "Move left... a bit more...")

  • If Yes: You need gRPC/WebSockets.

  • If No: Use REST.

• Do you need sub-second latency for scientific transients?

  • If Yes: You need a persistent socket (or very fast polling).

  • If No: Use REST.

My Advice: Stick to your "Start-Stop" idee (idea). It is much more robust for a distributed network of amateur hardware. Use standard REST (JSON over HTTP). It will save you weeks of debugging network code.

Would you like to see a Go struct for the "Job Ticket" that handles all the parameters (exposure time, filter, binning) in a single JSON object?