Event Hub MQTT Subscriptions

This block is capable of subscribing to multiple MQTT topics rather than just one root topic at a time. The data from all topics specified in a single Event Hub Publisher block will all be forwarded to that block's configured Predix Event Hub endpoint. The specific topics that data will be published to are specified in the topic map in the configuration file.

This block also supports an optional, configurable quality of service and client ID for its MQTT subscriptions.

Note: The Event Hub Publisher block does NOT currently support wildcard MQTT subscriptions (e.g., eventhub_data/#). Any wildcard subscriptions will not be properly forwarded to Predix Event Hub.

Note: The way the Event Hub Publisher block handles MQTT subscriptions and what Event Hub topics to publish to is significantly different from the way its predecessor, the Event Hub Cloud Gateway, handled them. Instead of configuring a root MQTT topic to subscribe to in the Cloud Gateway and forcing the adapters to publish to a subtopic of that root topic to determine what Event Hub topic to publish to, the new Event Hub Publisher block specifies a mapping between input MQTT topics and output Event Hub topics in its configuration file. This allows the adapters or any other data sources to be blissfully unaware of what Event Hub topics their data will eventually be published to. The cdpin block also should NOT be used in this Cloud Gateway to create MQTT subscriptions.