Troubleshooting

host.json

In order to get more detailed logging from this compentent, add the 'Host.Triggers.Mqtt' category to you logging configuration. The logging configuration for an Azure Function can be found in the host.json.

Example host.json:

{
    "logger": {
        "categoryFilter": {
            "categoryLevels": {
                "Host.Triggers.Mqtt": "Trace"
            }
        }
    },
    "tracing": {
        "consoleLevel": "verbose"
    }
}

Azure

Monitor recent runs:

• Go to the Function App in the Azure Portal
• Open the monitoring page for the the specific function
• Check the invocation log there
• The recent runs and their logging output should be there

Possible causes:

• Invalid configuration (no MqttConnection in the AppSettings?)
• Mqtt host not available
• Authentication issues
• Something else > please create an Issue

Try to run the Function locally and observe the Console Output.

If the local Console does not show the problem, we need the output of the Azure Functions hosts to observe what's going on. Either via Kudu or Application Insights.

• Go (back) to the 'Platform features' tab at the Function App level
• Open the 'Diagnostics Logs'
• Set 'Application Logging' to 'on' with the desired loglevel
• Make sure your function has been restarted

When using Application Insights (preferred):

• Make sure Application Insights is enabled for this function (at Function App level)
• Go to Application Insights and take a look at the logging

When not using Application Insights, use Kudu:

• Go to the 'Platform features' tab
• Click 'Advanced Tools (Kudu)'
• In Kudu, go to the Debug Console
• Read the logfiles in
  • home\LogFiles
  • home\LogFiles\Application\Functions\Host
  • home\LogFiles\Application\Functions\function\<<yourfucntionname>>