Query the message traces

This topic describes how to use the message trace query feature of Message Queue for MQTT. When messages are not sent and received as expected, you can use the message trace query feature to query the sending and delivery traces of messages.

1. Log on to the Message Queue for MQTT console.
2. In the left-side navigation pane, click Instances.
3. In the top navigation bar, select a region.
4. Find the instance on which you want to query the message traces in the instance list. In the Actions column, choose More > Message Trace Query.
5. On the Message Trace Query page, set the query conditions and the Time Range parameter as needed. Then, click Search.
   Note The maximum time span is one day.

   You must specify at least one query condition. You must set the Message ID parameter or both of the Group ID and Device ID parameters.

   • Query message traces by setting the Message ID parameter: You can use this method to perform an exact match to query the sending and delivery traces of a message.
   • Query message traces by setting the Group ID and Device ID parameters: You can use this method to perform a fuzzy match to query the messages of a Message Queue for MQTT client.

     In the query results, you can click Message Trace in the Actions column to view the sending and delivery traces of a message.