reference.conf

// Configuration file [HOCON format]

iothub-react {

  // Connection settings can be retrieved from the Azure portal at https://portal.azure.com
  // For more information about IoT Hub settings, see:
  //   https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-create-through-portal#endpoints
  //   https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-java-java-getstarted
  connection {

    // see: Endpoints ⇒ Messaging ⇒ Events ⇒ "Event Hub-compatible name"
    hubName = ${?IOTHUB_EVENTHUB_NAME}

    // see: Endpoints ⇒ Messaging ⇒ Events ⇒ "Event Hub-compatible endpoint"
    hubEndpoint = ${?IOTHUB_EVENTHUB_ENDPOINT}

    // see: Endpoints ⇒ Messaging ⇒ Events ⇒ Partitions
    hubPartitions = ${?IOTHUB_EVENTHUB_PARTITIONS}

    // see: "IoT Hub" ⇒ your hub ⇒ "Shared access policies"
    // e.g. you should use the predefined "service" policy
    accessPolicy = ${?IOTHUB_ACCESS_POLICY}

    // see: Shared access policies ⇒ key name ⇒ Primary key
    accessKey = ${?IOTHUB_ACCESS_KEY}

    // see: Shared access policies ⇒ key name ⇒ Connection string ⇒ "HostName"
    accessHostName = ${?IOTHUB_ACCESS_HOSTNAME}
  }

  streaming {

    // see: "IoT Hub" >> your hub > "Messaging" >> Consumer groups
    // "$Default" is predefined and is the typical scenario
    consumerGroup = "$Default"

    // How many messages to retrieve on each pull, max is 999
    receiverBatchSize = 999

    // Value expressed as a duration, e.g. 3s, 3000ms, "3 seconds", etc.
    receiverTimeout = 5s

    // Whether to retrieve information about the partitions while streming events from IoT Hub
    retrieveRuntimeInfo = false
  }

  checkpointing {

    // Checkpoints frequency (best effort), for each IoT hub partition
    // Min: 1 second, Max: 1 minute
    frequency = 15s

    // How many messages to stream before saving the position, for each IoT hub partition.
    // Since the stream position is saved in the Source, before the rest of the
    // Graph (Flows/Sinks), this provides a mechanism to replay buffered messages.
    // The value should be greater than receiverBatchSize
    countThreshold = 2000

    // Store a position if its value is older than this amount of time, ignoring the threshold.
    // For instance when the telemetry stops, this will force to write the last offset after some time.
    // Min: 1 second, Max: 1 hour. Value is rounded to seconds.
    timeThreshold = 5min

    storage {

      // Value expressed as a duration, e.g. 3s, 3000ms, "3 seconds", etc.
      rwTimeout = 5s

      // Supported types (not case sensitive): Cassandra, AzureBlob
      backendType = "AzureBlob"

      // If you use the same storage while processing multiple streams, you'll want
      // to use a distinct table/container/path in each job, to to keep state isolated
      namespace = "iothub-react-checkpoints"

      // com.microsoft.azure.iot.iothubreact.checkpointing.Backends.AzureBlob
      azureblob {
        // Time allowed for a checkpoint to be written, rounded to seconds (min 15, max 60)
        lease = 15s
        // Whether to use the Azure Storage Emulator
        useEmulator = false
        // Storage credentials
        protocol = "https"
        account = ${?IOTHUB_CHECKPOINT_ACCOUNT}
        key = ${?IOTHUB_CHECKPOINT_KEY}
      }

      cassandra {
        cluster = "localhost:9042"
        replicationFactor = 1
        username = ""
        password = ""
      }
    }
  }
}