After some experimentation I realised that I had forgotten that the order of message processing was important e.g. a TTI Queued message should be processed before the associated Ack. This could (and did happen) because I had a queue for each message type and in addition the Azure Queue Storage trigger binding would use parallel execution to process backlogs of messages. My approach caused issues with both intra and inter queue message ordering
I have one an Azure IoT HubLoRa Telemetry Field Gateway running in my office and I wanted to process the data collected by the sensors around my property without using a Software as a Service(SaaS) Internet of Things (IoT) package.
Rather than lots of screen grabs of my configuration steps I figured people reading this series of posts would be able to figure the details out themselves.
To confirm my event subscriptions were successful I previously found the “simplest” approach was to use an Azure storage queue endpoint. I had to create an Azure Storage Account with two Azure Storage Queues one for device connectivity (.DeviceConnected & .DeviceDisconnected) events and the other for device telemetry (.DeviceTelemetry) events.
I created a couple of other subscriptions so I could compare the different Event schemas (Event Grid Schema & Cloud Event Schema v1.0). At this stage I didn’t configure any Filters or Additional Features.
I use Cerebrate Cerculean for monitoring and managing a couple of other customer projects so I used it to inspect the messages in the storage queues.
Without writing any code (I will script the configuration) I could upload sensor data to an Azure IoT Hub, subscribe to a selection of events the Azure IoT Hub publishes and then inspect them in an Azure Storage Queue.
I did notice that the .DeviceConnected and .DeviceDisconnected events did take a while to arrive. When I started the field gateway application on the device I would get several DeviceTelemetry events before the DeviceConnected event arrived.