Device shadow state updates delayed when syncing via MQTT Pub/Sub bridge integration

nicoleexpert
Sun, 19 Jan 2025 16:42:29 +0000

We’re experiencing significant delays in device shadow state updates when devices publish state changes via MQTT to Cloud IoT Core. Our fleet of 800+ industrial sensors publishes state updates every 30 seconds, but the shadow state in the registry shows delays ranging from 2-5 minutes.

The Pub/Sub subscription is configured with default settings (ackDeadline: 10s), and devices are publishing with MQTT QoS 1. We’ve noticed that during peak hours (when 600+ devices are active), the shadow state propagation becomes even slower, affecting our real-time monitoring workflows.

Has anyone encountered similar latency issues with shadow state synchronization? We need shadows to reflect actual device state within 10-15 seconds for our alarm system to work properly.