Issue with notifications of buoys not transmitting data.

[Caesarh97]

Hi @echaidemenos,

On Internal, when checking deployed buoys with last_data_received, only the "null" values are being notified on Slack in the "notifications" channel. In the screenshot, you can see that only the SPOT-1435 was notified of the four buoys that didn't transmit data on Nov 21. What can be causing this, and is there a way to have all buoys that haven't transmitted in, for example, 24 hours to be notified on Slack?

Notes:

• It's great that even if only one sensor is transmitting, the buoys still appear as if we haven't received data from them. This helps me to identify what buoys that don't work. Sofar only has notifications for when no data is transmitted at all. Usually, only one sensor is not working, and it's rare that all sensors stop at the same time.
• Since we'll be redoing the backend, this is no rush. This can be fixed once we have moved away from Internal.io.

[ericboucher]

@echaidemenos we should update check-buoys-status.ts to check for more metrics or focus on temperature at least

For example, site 2188 | SPOT-30125R doesn't send a notification, but we're not getting temp data:

@Caesarh97 what are you most interested in in terms of alerts? Should we check that we are receiving both top temperature and bottom temperature? Something else?

[Caesarh97]

@ericboucher It would be great to receive alerts if 1 or more sensors are not transmitting data. For example, SPOT-1639 (Site 3256) is only transmitting data from 1 sensor. It would be great if I could receive notifications for buoys like those.

OBS: I haven't said this before, and you'll have to let me know if it would work or not. For the example above with SPOT-1639, this buoy/Aqualink is still deployed, and we want to keep it deployed. Could we add a maximum of consecutive days for alerts? For example, three days? If it's still not solved (changed to deployed in this case), the alerts will stop. If this is difficult or requires much work, please keep it as it is today. I'll just have to continue to set reminders to check the buoys regularly.