Maintenance¶

This chapter describes a few maintenance tasks that are needed to operate the network an API.

Managing deployments¶

The database, especially the metadata therein, is structured in a way that we have:

a collection of sensor that are known to belong to the network. They consists of different sensor types (blg, sht35, atm41)
a collections of stations (geographical sites) the network consists of
sensor deployments that combine the first two and assign (multiple) sensors to a station for a specific time span

Some changes to the network require manual changes to the metadata in the database via SQL.

Swapping a sensor¶

If a sensor is swapped for maintenance or after suffering damage due to vandalism or construction the following steps are needed.

Terminate the old sensor’s (DEC0054AD) deployment by:

locating the associated deployment via the Decentlab sensor id
```
SELECT * FROM sensor_deployment WHERE sensor_id = 'DEC0054AD';
```
which will return something like this:
```
 deployment_id | sensor_id | station_id |       setup_date       | teardown_date
---------------+-----------+------------+------------------------+---------------
            51 | DEC0054AD | DOTKPS     | 2024-08-15 23:59:00+00 |
```
and terminating the deployment by setting a teardown_date for the deployment_id (in this case 51). The date should correspond to the last known valid measurement. If the old station has already been completely removed from the Element platform, you will have to set the teardown_date exactly at or before the last valid measurement. Otherwise the system will still try to download data to fill the gap between the last existing measurement and the teardown_date resulting in an error (403).
```
UPDATE sensor_deployment SET teardown_date = '2025-11-28 05:40:00+00' WHERE deployment_id = 51;
```
Create a new deployment with the sensor that replaces the old sensor. Make sure that the station_id column is present in the element portal. If this is missing, the system cannot process the measurement since it cannot be unambiguously assigned a station. If this was not done right away, you will have to set the setup_date between the last value without a station_id and the first values with a station_id. Make sure the timezones match! The database only accept UTC. The Element UI will show timestamp in the browser’s timezone.
```
INSERT INTO
    sensor_deployment(sensor_id, station_id, setup_date)
VALUES
    ('DEC004D18', 'DOTKPS', '2025-12-12 10:54')
```

You may need to clean up erroneous data that was recorded after the last valid measurement and before the beginning of the new deployment

DELETE FROM temp_rh_data
WHERE
    station_id = 'DOTKPS' AND
    measured_at BETWEEN '2025-11-28 05:41:00+00' AND '2025-12-12 10:54';

To also make the changes apply to the aggregated data (hourly and daily), you may simply wait a day (until 01:03:00 UTC) when a routine job is started, fully refreshing all views. If the changes must apply immediately, you may start the task manually by running on the container host:
```
docker exec -it celery celery -A app.tasks call refresh-all-views
```