Firestore Read Limit Exceeded

[dongphusang]

Context

• Terra components (embedded and mobile app) are unable to read from firestore service. After examination on firestore panel, the system would reach the read limits around 8PM, rendering the service unavailable to Terra components.
• Upon inspecting the components, it was the ESP32 that causes such problem. Specifically, It would make approx 3000 reads per hour, every day. This is because the ESP32 was configured to pull data from firestore every second to evaluate watering schedule, or in other words, to see if it is time to water the plants.

[dongphusang]

Solution

• Grouped all documents into a single document related to the current MCU. Reducing reads down to approx 43k transactions per day, keeping MCU operational and not blocked by GCP.