public static async Task Run(IReadOnlyCollection <Document> input, CancellationToken token)
{
foreach (Document doc in input)
{
// Deserialize the incoming document and event data
TelemetryOutput to = LoadTelemetryRecord(doc);
MessageBody msg = JsonConvert.DeserializeObject <MessageBody>(to.event_data);
// Write telemetry event to Postgres
WriteTelemetryEventToPostgres(to);
// Perform Azure ML call and build a new output object
InputData payload = new InputData();
var machinetemp = msg.machine.temperature;
var pressure = msg.machine.pressure;
payload.data = new List <PredictionInput> {
new PredictionInput {
MachineTemperature = machinetemp, Pressure = pressure
}
};
int maintenanceRecommendation = GetMaintenancePrediction(payload);
TelemetryOutput newTo = CreateNewTelemetryOutput(to, msg, maintenanceRecommendation);
// Write maintenance recommendation events for downstream processing
WriteTelemetryEventToPostgres(newTo);
await WriteTelemetryEventToEventHub(newTo);
}
}
public static async Task WriteTelemetryEventToEventHub(TelemetryOutput to)
{
await using (var producerClient = new EventHubProducerClient(eventHubConnection, eventHubName))
{
using EventDataBatch eventBatch = await producerClient.CreateBatchAsync();
string msg = JsonConvert.SerializeObject(to);
eventBatch.TryAdd(new EventData(Encoding.UTF8.GetBytes(msg)));
await producerClient.SendAsync(eventBatch);
}
}
public static TelemetryOutput LoadTelemetryRecord(Document doc)
{
TelemetryOutput to = new TelemetryOutput();
to.entity_id = doc.GetPropertyValue <string>("entity_id");
to.entity_type = doc.GetPropertyValue <string>("entity_type");
to.event_data = doc.GetPropertyValue <string>("event_data");
to.event_type = doc.GetPropertyValue <string>("event_type");
to.machineid = doc.GetPropertyValue <int>("machineid");
to.id = doc.GetPropertyValue <string>("id");
return(to);
}
public static void WriteTelemetryEventToPostgres(TelemetryOutput to)
{
string insertCommand = @"INSERT INTO event(
machine_id,
event_id,
event_type,
entity_type,
entity_id,
event_data
)
VALUES
(
@machine_id,
@event_id,
@event_type,
@entity_type,
@entity_id,
CAST(@event_data AS json)
);";
// Connect to Postgres
var connStr = Environment.GetEnvironmentVariable("pg_connection");
using (var conn = new NpgsqlConnection(connStr))
{
conn.Open();
using (var cmd = new NpgsqlCommand(insertCommand, conn))
{
cmd.Parameters.AddWithValue("machine_id", to.machineid);
cmd.Parameters.AddWithValue("event_id", to.id);
cmd.Parameters.AddWithValue("event_type", to.event_type);
cmd.Parameters.AddWithValue("entity_type", to.entity_type);
cmd.Parameters.AddWithValue("entity_id", to.entity_id);
cmd.Parameters.AddWithValue("event_data", to.event_data);
cmd.ExecuteNonQuery();
}
}
}
public static TelemetryOutput CreateNewTelemetryOutput(TelemetryOutput to, MessageBody msg, int maintenanceRecommendation)
{
var newMsgBody = new MaintenancePredictionMessageBody
{
factoryId = msg.factoryId,
machine = msg.machine,
ambient = msg.ambient,
timeCreated = DateTime.UtcNow.ToString("yyyy-MM-ddTHH:mm:ssZ"),
maintenanceRecommendation = maintenanceRecommendation
};
string newMsg = JsonConvert.SerializeObject(newMsgBody);
TelemetryOutput newTo = new TelemetryOutput
{
id = System.Guid.NewGuid().ToString(),
machineid = to.machineid,
event_type = "Maintenance Prediction",
entity_type = "MachineTelemetry",
entity_id = to.entity_id,
event_data = newMsg
};
return(newTo);
}
