Viewing MQTT client-related statistics by using REST Monitoring APIs

System administrators can view MQTT client-related statistics by using a REST Monitoring API.

System administrators can view (dis)connected MQTT client-related statistics by using a REST Monitoring API, or by using the Amlen WebUI. For more information about using the Amlen WebUI to view disconnected MQTT client-related statistics, see Viewing MQTT client-related statistics by using the GUI.

MQTT client-related monitoring statistics can be created by using a REST Monitoring API. To create MQTT client-related monitoring statistics, complete the following steps:
  1. Use the Eclipse Amlen REST API GET method with the following Eclipse Amlen configuration URI:

    http://<admin-endpoint-IP:Port>/ima/v1/monitor/<Object Type>

  2. Provide query parameters requesting the statistics that you want returned in the JSON payload. The following example uses cURL to create MQTT client-related statistics: 
    curl -X GET http://127.0.0.1:9089/ima/v1/monitor/MQTTClient?ClientID=ClientID%26StatType=StatType%26ConnectionState=&ConnectionState%26ResultCount=ResultCount

    Where:

    • ClientID
      Optional.

      Specifies the name of the MQTT Client.

      Asterisk (*) matches 0 or more characters. To use an asterisk (*), you must specify ClientID in the query.

      The default value is *.

    • ResultCount
      Optional.

      Specifies the number of results to display. (Ignored if StatType is set to AllUnsorted)

      Options available for selection are 10, 25, 50, and 100.

      The default is 25.

    • ConnectionState
      Optional.

      Lists connected clients, or both connected and disconnected clients.

      This value can be one of the following values:

      • Disconnected
        Lists durable clients that are disconnected from Eclipse Amlen.
      • Connected
        Lists clients that are connected to Eclipse Amlen.
      • All
        Lists all clients, whether they are disconnected, or connected to Eclipse Amlen.

      The default value is Disconnected.

    • StatType
      Optional.

      Specifies the type of data to order the results by.

      This value can be the following values:

      • LastConnectedTimeOldest
        The most recent date that the specified client ID connected to Eclipse Amlen.
      • AllUnsorted

        Lists all MQTT client IDs that are connected to Eclipse Amlen.

        Any value that is specified for ResultCount is ignored, so setting StatType to AllUnsorted can result in a large number of responses being generated.

      The default value is LastConnectedTimeOldest.

The following fields are returned:
  • ClientID
    String
    The Client ID.
  • IsConnected
    Boolean
    Whether the client is connected to the Eclipse Amlen server. Only disconnected clients are shown.
  • LastConnectedTime
    Numeric
    Specifies the number of microseconds since the client last connected to the Eclipse Amlen server.

The following example uses cURL to show how a GET method is used to create statistics about a disconnected MQTT Client with a Client ID that is set to DemoClientID:

curl -X GET http://127.0.0.1:9089/ima/v1/monitor/MQTTClient?ClientID=DemoClientID

The following example shows a successful example response to the GET method that was used to create statistics about a disconnected MQTT Client with a Client ID that is set to DemoClientID:

{ "Version":"v1", "MQTTClient": [ { "ClientID":"DemoClientID","IsConnected":False,"LastConnectedTime":1446728129213566618 } ] }