Limitations of MQTT Support in Integration Server
MQTT support in Integration Server has the following limitations:
Enhanced logging, which instructs
Integration Server to write detailed log entries when sending, receiving or processing messages, cannot be used with MQTT.
MQTT connection aliases do not have a client side queue (CSQ) which is an available feature for other types of messaging connection aliases in
Integration Server.
Exactly-once message processing feature is not available for MQTT triggers.
In a cluster of
Integration Servers, identically named MQTT triggers and MQTT connection aliases should not exist on each node in the cluster. Furthermore, MQTT connection aliases in a cluster should all use unique connection client IDs. No duplicate connection client IDs should be used.
The cluster limitations are because the MQTT specification does not support multiple clients sharing a subscription. Identical MQTT triggers share the same subscriptions and the same connection client ID. The connection client ID of the MQTT trigger is the connection client ID value of the MQTT connection alias plus the trigger name.
Because of adherence to the MQTT specification, some MQTT providers do not support a shared subscription and the use of the same connection client ID by multiple clients. Some MQTT providers may offer a workaround for this restriction.