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Monitoring Azure IoT Hub data reference

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To get started with Azure monitoring, see Monitor Azure IoT Hub to understand how to collect and analyze monitoring data for Azure IoT Hub.

This article is a reference for implementing Azure monitoring.

The major sections in this reference article:

Metrics

This section lists all the automatically collected platform metrics for Azure IoT Hub. The resource provider namespace for IoT Hub metrics is Microsoft.Devices and the type Namespace is IoTHubs.

The following subsections show the IoT Hub platform metrics by general category and list metrics by their display name as assigned in the Azure portal.

You can also find a single table that lists all the IoT Hub platform metrics by metric name under Microsoft.Devices/IotHubs in the Azure Monitor documentation. This table doesn't provide all information, like supported aggregations for some metrics, available in this article.

To learn about metrics supported by other Azure services, see Supported metrics with Azure Monitor.

Topics in this section

Select a topic to jump to its information on this page.

Supported aggregations

The Aggregation Type column in each table corresponds to the default aggregation that is used when the metric is selected for a chart or alert.

Screenshot showing aggregation for metrics

For most metrics, all aggregation types are valid; however, for count metrics with a Unit column value of Count, only some aggregations are valid. Count metrics can be one of two types:

  • For Single-point count metrics, IoT Hub registers a single data point (essentially a 1) every time the measured operation occurs. Azure Monitor then sums these data points over the specified granularity. Examples of Single-point metrics are Telemetry messages sent and C2D message deliveries completed. For these metrics, the only relevant aggregation type is Total (Sum). The portal allows you to choose minimum, maximum, and average; however, these values will always be 1.

  • For Snapshot count metrics, IoT Hub registers a total count when the measured operation occurs. Currently, there are three Snapshot metrics emitted by IoT Hub: Total number of messages used, Total devices, and Connected devices. Because these metrics present a "total" quantity every time they're emitted, summing them over the specified granularity makes no sense. Azure Monitor limits you to selecting average, minimum, and maximum for the aggregation type for these metrics.

Cloud to device command metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
C2D Messages Expired C2DMessagesExpired Count Total Number of expired cloud-to-device messages None
C2D message deliveries completed c2d.commands.egress.complete.success Count Total Number of cloud-to-device message deliveries completed successfully by the device None
C2D messages abandoned c2d.commands.egress.abandon.success Count Total Number of cloud-to-device messages abandoned by the device None
C2D messages rejected c2d.commands.egress.reject.success Count Total Number of cloud-to-device messages rejected by the device None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Cloud to device direct methods metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Failed direct method invocations c2d.methods.failure Count Total The count of all failed direct method calls. None
Request size of direct method invocations c2d.methods.requestSize Bytes Average The count of all successful direct method requests. None
Response size of direct method invocations c2d.methods.responseSize Bytes Average The count of all successful direct method responses. None
Successful direct method invocations c2d.methods.success Count Total The count of all successful direct method calls. None

For metrics with a Unit value of Count only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Cloud to device twin operations metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Failed twin reads from back end c2d.twin.read.failure Count Total The count of all failed back-end-initiated twin reads. None
Failed twin updates from back end c2d.twin.update.failure Count Total The count of all failed back-end-initiated twin updates. None
Response size of twin reads from back end c2d.twin.read.size Bytes Average The count of all successful back-end-initiated twin reads. None
Size of twin updates from back end c2d.twin.update.size Bytes Average The total size of all successful back-end-initiated twin updates. None
Successful twin reads from back end c2d.twin.read.success Count Total The count of all successful back-end-initiated twin reads. None
Successful twin updates from back end c2d.twin.update.success Count Total The count of all successful back-end-initiated twin updates. None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Configurations metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Configuration Metrics configurations Count Total Number of total CRUD operations performed for device configuration and IoT Edge deployment, on a set of target devices. Included are the number of operations that modify the device twin or module twin because of these configurations. None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Daily quota metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Total device data usage deviceDataUsage Bytes Total Bytes transferred to and from any devices connected to IotHub None
Total device data usage (preview) deviceDataUsageV2 Bytes Total Bytes transferred to and from any devices connected to IotHub None
Total number of messages used dailyMessageQuotaUsed Count Average Number of total messages used today. A cumulative value that is reset to zero at 00:00 UTC every day. None

For Total number of messages used, only minimum, maximum, and average aggregations are supported. For more information, see Supported aggregations.

Device metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Total devices (deprecated) devices.totalDevices Count Total Number of devices registered to your IoT hub None
Connected devices (deprecated) devices.connectedDevices.allProtocol Count Total Number of devices connected to your IoT hub None
Total devices totalDeviceCount Count Average Number of devices registered to your IoT hub None
Connected devices connectedDeviceCount Count Average Number of devices connected to your IoT hub None

For Total devices (deprecated) and Connected devices (deprecated), only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

For Total devices and Connected devices, only minimum, maximum, and average aggregations are valid. For more information, see Supported aggregations.

Total devices and Connected devices aren't exportable via diagnostic settings.

Device telemetry metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Number of throttling errors d2c.telemetry.ingress.sendThrottle Count Total Number of throttling errors due to device throughput throttles None
Telemetry 'message send' attempts d2c.telemetry.ingress.allProtocol Count Total Number of device-to-cloud telemetry messages attempted to be sent to your IoT hub None
Telemetry messages sent d2c.telemetry.ingress.success Count Total Number of device-to-cloud telemetry messages sent successfully to your IoT hub None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Device to cloud twin operations metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Failed twin reads from devices d2c.twin.read.failure Count Total The count of all failed device-initiated twin reads. None
Failed twin updates from devices d2c.twin.update.failure Count Total The count of all failed device-initiated twin updates. None
Response size of twin reads from devices d2c.twin.read.size Bytes Average The number of all successful device-initiated twin reads. None
Size of twin updates from devices d2c.twin.update.size Bytes Average The total size of all successful device-initiated twin updates. None
Successful twin reads from devices d2c.twin.read.success Count Total The count of all successful device-initiated twin reads. None
Successful twin updates from devices d2c.twin.update.success Count Total The count of all successful device-initiated twin updates. None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Event Grid metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Event Grid deliveries EventGridDeliveries Count Total The number of IoT Hub events published to Event Grid. Use the Result dimension for the number of successful and failed requests. EventType dimension shows the type of event (https://aka.ms/ioteventgrid). Result,
EventType
For more information, see Metric dimensions.
Event Grid latency EventGridLatency Milliseconds Average The average latency (milliseconds) from when the Iot Hub event was generated to when the event was published to Event Grid. This number is an average between all event types. Use the EventType dimension to see latency of a specific type of event. EventType
For more information, see Metric dimensions.

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Jobs metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Completed jobs jobs.completed Count Total The count of all completed jobs. None
Failed calls to list jobs jobs.listJobs.failure Count Total The count of all failed calls to list jobs. None
Failed creations of method invocation jobs jobs.createDirectMethodJob.failure Count Total The count of all failed creation of direct method invocation jobs. None
Failed creations of twin update jobs jobs.createTwinUpdateJob.failure Count Total The count of all failed creation of twin update jobs. None
Failed job cancellations jobs.cancelJob.failure Count Total The count of all failed calls to cancel a job. None
Failed job queries jobs.queryJobs.failure Count Total The count of all failed calls to query jobs. None
Failed jobs jobs.failed Count Total The count of all failed jobs. None
Successful calls to list jobs jobs.listJobs.success Count Total The count of all successful calls to list jobs. None
Successful creations of method invocation jobs jobs.createDirectMethodJob.success Count Total The count of all successful creation of direct method invocation jobs. None
Successful creations of twin update jobs jobs.createTwinUpdateJob.
success		 Count Total The count of all successful creation of twin update jobs. None
Successful job cancellations jobs.cancelJob.success Count Total The count of all successful calls to cancel a job. None
Successful job queries jobs.queryJobs.success Count Total The count of all successful calls to query jobs. None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Routing metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Routing Deliveries (preview) RoutingDeliveries Count Total The routing delivery metric. Use the dimensions to identify the delivery status for a specific endpoint or for a specific routing source. Result,
RoutingSource,
EndpointType,
FailureReasonCategory,
EndpointName
For more information, see Metric dimensions.
Routing Delivery Message Size In Bytes (preview) RoutingDataSizeInBytesDelivered Bytes Total The total number of bytes routed by IoT Hub to custom endpoint and built-in endpoint. Use the dimensions to identify data size routed to a specific endpoint or for a specific routing source. RoutingSource,
EndpointType
EndpointName
For more information, see Metric dimensions.
Routing Delivery Latency (preview) RoutingDeliveryLatency Milliseconds Average The routing delivery latency metric. Use the dimensions to identify the latency for a specific endpoint or for a specific routing source. RoutingSource,
EndpointType,
EndpointName
For more information, see Metric dimensions.
Routing: blobs delivered to storage d2c.endpoints.egress.storage.blobs Count Total The number of times IoT Hub routing delivered blobs to storage endpoints. None
Routing: data delivered to storage d2c.endpoints.egress.storage.bytes Bytes Total The amount of data (bytes) IoT Hub routing delivered to storage endpoints. None
Routing: message latency for Event Hubs d2c.endpoints.latency.eventHubs Milliseconds Average The average latency (milliseconds) between message ingress to IoT Hub and message ingress into custom endpoints of type Event Hubs. Messages routes to built-in endpoint (events) aren't included. None
Routing: message latency for Service Bus Queue d2c.endpoints.latency.serviceBusQueues Milliseconds Average The average latency (milliseconds) between message ingress to IoT Hub and message ingress into a Service Bus queue endpoint. None
Routing: message latency for Service Bus Topic d2c.endpoints.latency.serviceBusTopics Milliseconds Average The average latency (milliseconds) between message ingress to IoT Hub and message ingress into a Service Bus topic endpoint. None
Routing: message latency for messages/events d2c.endpoints.latency.builtIn.events Milliseconds Average The average latency (milliseconds) between message ingress to IoT Hub and message ingress into the built-in endpoint (messages/events) and fallback route. None
Routing: message latency for storage d2c.endpoints.latency.storage Milliseconds Average The average latency (milliseconds) between message ingress to IoT Hub and message ingress into a storage endpoint. None
Routing: messages delivered to Event Hubs d2c.endpoints.egress.eventHubs Count Total The number of times IoT Hub routing successfully delivered messages to custom endpoints of type Event Hubs. Messages routes to built-in endpoint (events) aren't included. None
Routing: messages delivered to Service Bus Queue d2c.endpoints.egress.serviceBusQueues Count Total The number of times IoT Hub routing successfully delivered messages to Service Bus queue endpoints. None
Routing: messages delivered to Service Bus Topic d2c.endpoints.egress.serviceBusTopics Count Total The number of times IoT Hub routing successfully delivered messages to Service Bus topic endpoints. None
Routing: messages delivered to fallback d2c.telemetry.egress.fallback Count Total The number of times IoT Hub routing delivered messages to the endpoint associated with the fallback route. None
Routing: messages delivered to messages/events d2c.endpoints.egress.builtIn.events Count Total The number of times IoT Hub routing successfully delivered messages to the built-in endpoint (messages/events) and fallback route. None
Routing: messages delivered to storage d2c.endpoints.egress.storage Count Total The number of times IoT Hub routing successfully delivered messages to storage endpoints. None
Routing: telemetry messages delivered d2c.telemetry.egress.success Count Total The number of times messages were successfully delivered to all endpoints using IoT Hub routing. If a message is routed to multiple endpoints, this value increases by one for each successful delivery. If a message is delivered to the same endpoint multiple times, this value increases by one for each successful delivery. None
Routing: telemetry messages dropped  d2c.telemetry.egress.dropped Count Total The number of times messages were dropped by IoT Hub routing due to dead endpoints. This value doesn't count messages delivered to fallback route as dropped messages aren't delivered there. None
Routing: telemetry messages incompatible d2c.telemetry.egress.invalid Count Total The number of times IoT Hub routing failed to deliver messages due to an incompatibility with the endpoint. A message is incompatible with an endpoint when Iot Hub attempts to deliver the message to an endpoint and it fails with a non-transient error. Invalid messages aren't retried. This value doesn't include retries. None
Routing: telemetry messages orphaned  d2c.telemetry.egress.orphaned Count Total The number of times messages were orphaned by IoT Hub routing because they didn't match any routing query, when fallback route is disabled. None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Twin query metrics

Metric Display Name Metric Unit Aggregation Type Description Dimensions
Failed twin queries twinQueries.failure Count Total The count of all failed twin queries. None
Successful twin queries twinQueries.success Count Total The count of all successful twin queries. None
Twin queries result size twinQueries.resultSize Bytes Average The total of the result size of all successful twin queries. None

For metrics with a Unit value of Count, only total (sum) aggregation is valid. Minimum, maximum, and average aggregations always return 1. For more information, see Supported aggregations.

Metric dimensions

Azure IoT Hub has the following dimensions associated with some of its routing and Event Grid metrics.

Dimension Name Description
EndpointName The endpoint name
EndpointType eventHubs, serviceBusQueues, cosmosDB, serviceBusTopics. builtin, or blobStorage
EventType Microsoft.Devices.DeviceCreated. Microsoft.Devices.DeviceDeleted, Microsoft.Devices.DeviceConnected, Microsoft.Devices.DeviceDisconnected, or Microsoft.Devices.DeviceTelemetry
For more information, see Event types.
FailureReasonCategory One of the following: invalid, dropped, orphaned, or null.
Result Either success or failure
RoutingSource Device Messages
Twin Change Events
Device Lifecycle Events

To learn more about metric dimensions, see Multi-dimensional metrics.

Resource logs

This section lists all the resource log category types and schemas collected for Azure IoT Hub. The resource provider and type for all IoT Hub logs is Microsoft.Devices/IotHubs. Events are emitted only for errors in some categories.

Topics in this section

Connections

The connections category tracks device connect and disconnect events from an IoT hub and errors. This category is useful for identifying unauthorized connection attempts and or alerting when you lose connection to devices.

For reliable connection status of devices, see Monitor device connection status.

{
   "records":
   [
        {
            "time": " UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "deviceConnect",
            "category": "Connections",
            "level": "Information",
            "properties": "{\"deviceId\":\"<deviceId>\",\"sdkVersion\":\"<sdkVersion>\",\"protocol\":\"<protocol>\",\"authType\":\"{\\\"scope\\\":\\\"device\\\",\\\"type\\\":\\\"sas\\\",\\\"issuer\\\":\\\"iothub\\\",\\\"acceptingIpFilterRule\\\":null}\",\"maskedIpAddress\":\"<maskedIpAddress>\"}",
            "location": "Resource location"
        }
    ]
}

For detailed information about using connections logs to monitor device connectivity, see Monitor, diagnose, and troubleshoot device connectivity to Azure IoT Hub.

Device telemetry

The device telemetry category tracks errors that occur at the IoT hub and are related to the telemetry pipeline. This category includes errors that occur when sending telemetry events (such as throttling) and receiving telemetry events (such as unauthorized reader). This category can't catch errors caused by code running on the device itself.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "ingress",
            "category": "DeviceTelemetry",
            "level": "Error",
            "resultType": "Event status",
            "resultDescription": "MessageDescription",
            "properties": "{\"deviceId\":\"<deviceId>\",\"batching\":\"0\",\"messageSizeInBytes\":\"<messageSizeInBytes>\",\"EventProcessedUtcTime\":\"<UTC timestamp>\",\"EventEnqueuedUtcTime\":\"<UTC timestamp>\",\"partitionId\":\"1\"}", 
            "location": "Resource location"
        }
    ]
}

Cloud-to-device commands

The cloud-to-device commands category tracks errors that occur at the IoT hub and are related to the cloud-to-device message pipeline. This category includes errors that occur from:

  • Sending cloud-to-device messages (like unauthorized sender errors),
  • Receiving cloud-to-device messages (like delivery count exceeded errors), and
  • Receiving cloud-to-device message feedback (like feedback expired errors).

This category doesn't catch errors when the cloud-to-device message is delivered successfully but then improperly handled by the device.

{
    "records":
    [
        {
            "time": " UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "messageExpired",
            "category": "C2DCommands",
            "level": "Error",
            "resultType": "Event status",
            "resultDescription": "MessageDescription",
            "properties": "{\"deviceId\":\"<deviceId>\",\"messageId\":\"<messageId>\",\"messageSizeInBytes\":\"<messageSize>\",\"protocol\":\"Amqp\",\"deliveryAcknowledgement\":\"<None, NegativeOnly, PositiveOnly, Full>\",\"deliveryCount\":\"0\",\"expiryTime\":\"<timestamp>\",\"timeInSystem\":\"<timeInSystem>\",\"ttl\":<ttl>, \"EventProcessedUtcTime\":\"<UTC timestamp>\",\"EventEnqueuedUtcTime\":\"<UTC timestamp>\", \"maskedIpAddress\": \"<maskedIpAddress>\", \"statusCode\": \"4XX\"}",
            "location": "Resource location"
        }
    ]
}

Device identity operations

The device identity operations category tracks errors that occur when you attempt to create, update, or delete an entry in your IoT hub's identity registry. Tracking this category is useful for provisioning scenarios.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "get",
            "category": "DeviceIdentityOperations",
            "level": "Error",
            "resultType": "Event status",
            "resultDescription": "MessageDescription",
            "properties": "{\"maskedIpAddress\":\"<maskedIpAddress>\",\"deviceId\":\"<deviceId>\", \"statusCode\":\"4XX\"}",
            "location": "Resource location"
        }
    ]
}

File upload operations

The file upload category tracks errors that occur at the IoT hub and are related to file upload functionality. This category includes:

  • Errors that occur with the SAS URI, such as when it expires before a device notifies the hub of a completed upload.

  • Failed uploads reported by the device.

  • Errors that occur when a file isn't found in storage during IoT Hub notification message creation.

This category can't catch errors that directly occur while the device is uploading a file to storage.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "ingress",
            "category": "FileUploadOperations",
            "level": "Error",
            "resultType": "Event status",
            "resultDescription": "MessageDescription",
            "durationMs": "1",
            "properties": "{\"deviceId\":\"<deviceId>\",\"protocol\":\"<protocol>\",\"authType\":\"{\\\"scope\\\":\\\"device\\\",\\\"type\\\":\\\"sas\\\",\\\"issuer\\\":\\\"iothub\\\",\\\"acceptingIpFilterRule\\\":null}\",\"blobUri\":\"http//bloburi.com\"}",
            "location": "Resource location"
        }
    ]
}

Routes

The message routing category tracks errors that occur during message route evaluation and endpoint health as perceived by IoT Hub. This category includes events such as:

  • A rule evaluates to "undefined",
  • IoT Hub marks an endpoint as dead, or
  • Any errors received from an endpoint.

This category doesn't include specific errors about the messages themselves (like device throttling errors), which are reported under the "device telemetry" category.

{
    "records":
    [
        {
            "time":"2019-12-12T03:25:14Z",
            "resourceId":"/SUBSCRIPTIONS/91R34780-3DEC-123A-BE2A-213B5500DFF0/RESOURCEGROUPS/ANON-TEST/PROVIDERS/MICROSOFT.DEVICES/IOTHUBS/ANONHUB1",
            "operationName":"endpointUnhealthy",
            "category":"Routes",
            "level":"Error",
            "resultType":"403004",
            "resultDescription":"DeviceMaximumQueueDepthExceeded",
            "properties":"{\"deviceId\":null,\"endpointName\":\"anon-sb-1\",\"messageId\":null,\"details\":\"DeviceMaximumQueueDepthExceeded\",\"routeName\":null,\"statusCode\":\"403\"}",
            "location":"westus"
        }
    ]
}

Here are more details on routing resource logs:

Device-to-cloud twin operations

The device-to-cloud twin operations category tracks device-initiated events on device twins. These operations can include get twin, update reported properties, and subscribe to desired properties.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "update",
            "category": "D2CTwinOperations",
            "level": "Information",
            "durationMs": "1",
            "properties": "{\"deviceId\":\"<deviceId>\",\"protocol\":\"<protocol>\",\"authenticationType\":\"{\\\"scope\\\":\\\"device\\\",\\\"type\\\":\\\"sas\\\",\\\"issuer\\\":\\\"iothub\\\",\\\"acceptingIpFilterRule\\\":null}\"}",
            "location": "Resource location"
        }
    ]
}

Cloud-to-device twin operations

The cloud-to-device twin operations category tracks service-initiated events on device twins. These operations can include get twin, update or replace tags, and update or replace desired properties.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "read",
            "category": "C2DTwinOperations",
            "level": "Information",
            "durationMs": "1",
            "properties": "{\"deviceId\":\"<deviceId>\",\"sdkVersion\":\"<sdkVersion>\",\"messageSize\":\"<messageSize>\"}",
            "location": "Resource location"
        }
    ]
}

Twin queries

The twin queries category reports on query requests for device twins that are initiated in the cloud.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "query",
            "category": "TwinQueries",
            "level": "Information",
            "durationMs": "1",
            "properties": "{\"query\":\"<twin query>\",\"sdkVersion\":\"<sdkVersion>\",\"messageSize\":\"<messageSize>\",\"pageSize\":\"<pageSize>\", \"continuation\":\"<true, false>\", \"resultSize\":\"<resultSize>\"}",
            "location": "Resource location"
        }
    ]
}

Jobs operations

The jobs operations category reports on job requests to update device twins or invoke direct methods on multiple devices. These requests are initiated in the cloud.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "jobCompleted",
            "category": "JobsOperations",
            "level": "Information",
            "durationMs": "1",
            "properties": "{\"jobId\":\"<jobId>\", \"sdkVersion\": \"<sdkVersion>\",\"messageSize\": <messageSize>,\"filter\":\"DeviceId IN ['1414ded9-b445-414d-89b9-e48e8c6285d5']\",\"startTimeUtc\":\"Wednesday, September 13, 2017\",\"duration\":\"0\"}",
            "location": "Resource location"
        }
    ]
}

Direct Methods

The direct methods category tracks request-response interactions sent to individual devices. These requests are initiated in the cloud.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "send",
            "category": "DirectMethods",
            "level": "Information",
            "durationMs": "1",
            "properties": "{\"deviceId\":<messageSize>, \"RequestSize\": 1, \"ResponseSize\": 1, \"sdkVersion\": \"2017-07-11\"}",
            "location": "Resource location"
        }
    ]
}

Distributed Tracing (Preview)

The distributed tracing category tracks the correlation IDs for messages that carry the trace context header. To fully enable these logs, client-side code must be updated by following Analyze and diagnose IoT applications end-to-end with IoT Hub distributed tracing (preview).

The correlationId conforms to the W3C Trace Context proposal, where it contains a trace-id and a span-id.

IoT Hub D2C (device-to-cloud) logs

IoT Hub records this log when a message containing valid trace properties arrives at IoT Hub.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "DiagnosticIoTHubD2C",
            "category": "DistributedTracing",
            "correlationId": "00-8cd869a412459a25f5b4f31311223344-0144d2590aacd909-01",
            "level": "Information",
            "resultType": "Success",
            "resultDescription":"Receive message success",
            "durationMs": "",
            "properties": "{\"messageSize\": 1, \"deviceId\":\"<deviceId>\", \"callerLocalTimeUtc\": : \"2017-02-22T03:27:28.633Z\", \"calleeLocalTimeUtc\": \"2017-02-22T03:27:28.687Z\"}",
            "location": "Resource location"
        }
    ]
}

Here, durationMs isn't calculated as IoT Hub's clock might not be in sync with the device clock, and thus a duration calculation can be misleading. We recommend writing logic using the timestamps in the properties section to capture spikes in device-to-cloud latency.

Property Type Description
messageSize Integer The size of device-to-cloud message in bytes
deviceId String of ASCII 7-bit alphanumeric characters The identity of the device
callerLocalTimeUtc UTC timestamp The creation time of the message as reported by the device local clock
calleeLocalTimeUtc UTC timestamp The time of message arrival at the IoT Hub's gateway as reported by IoT Hub service side clock

IoT Hub ingress logs

IoT Hub records this log when message containing valid trace properties writes to internal or built-in Event Hubs.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "DiagnosticIoTHubIngress",
            "category": "DistributedTracing",
            "correlationId": "00-8cd869a412459a25f5b4f31311223344-349810a9bbd28730-01",
            "level": "Information",
            "resultType": "Success",
            "resultDescription":"Ingress message success",
            "durationMs": "10",
            "properties": "{\"isRoutingEnabled\": \"true\", \"parentSpanId\":\"0144d2590aacd909\"}",
            "location": "Resource location"
        }
    ]
}

In the properties section, this log contains additional information about message ingress.

Property Type Description
isRoutingEnabled String Either true or false, indicates whether or not message routing is enabled in the IoT Hub
parentSpanId String The span-id of the parent message, which would be the D2C message trace in this case

IoT Hub egress logs

IoT Hub records this log when routing is enabled and the message is written to an endpoint. If routing isn't enabled, IoT Hub doesn't record this log.

{
    "records":
    [
        {
            "time": "UTC timestamp",
            "resourceId": "Resource Id",
            "operationName": "DiagnosticIoTHubEgress",
            "category": "DistributedTracing",
            "correlationId": "00-8cd869a412459a25f5b4f31311223344-98ac3578922acd26-01",
            "level": "Information",
            "resultType": "Success",
            "resultDescription":"Egress message success",
            "durationMs": "10",
            "properties": "{\"endpointType\": \"EventHub\", \"endpointName\": \"myEventHub\", \"parentSpanId\":\"349810a9bbd28730\"}",
            "location": "Resource location"
        }
    ]
}

In the properties section, this log contains additional information about message ingress.

Property Type Description
endpointName String The name of the routing endpoint
endpointType String The type of the routing endpoint
parentSpanId String The span-id of the parent message, which would be the IoT Hub ingress message trace in this case

Configurations

IoT Hub configuration logs track events and error for the Automatic Device Management feature set.

{
    "records":
    [
         {
             "time": "2019-09-24T17:21:52Z",
             "resourceId": "Resource Id",
             "operationName": "ReadManyConfigurations",
             "category": "Configurations",
             "resultType": "",
             "resultDescription": "",
             "level": "Information",
             "durationMs": "17",
             "properties": "{\"configurationId\":\"\",\"sdkVersion\":\"2018-06-30\",\"messageSize\":\"0\",\"statusCode\":null}",
             "location": "southcentralus"
         }
    ]
}

Device Streams (Preview)

The device streams category tracks request-response interactions sent to individual devices.

{
    "records":
    [
         {
             "time": "2019-09-19T11:12:04Z",
             "resourceId": "Resource Id",
             "operationName": "invoke",
             "category": "DeviceStreams",
             "resultType": "",
             "resultDescription": "",    
             "level": "Information",
             "durationMs": "74",
             "properties": "{\"deviceId\":\"myDevice\",\"moduleId\":\"myModule\",\"sdkVersion\":\"2019-05-01-preview\",\"requestSize\":\"3\",\"responseSize\":\"5\",\"statusCode\":null,\"requestName\":\"myRequest\",\"direction\":\"c2d\"}",
             "location": "Central US"
         }
    ]
}

Azure Monitor Logs tables

This section refers to all of the Azure Monitor Logs Kusto tables relevant to Azure IoT Hub and available for query by Log Analytics. For a list of these tables and links to more information for the IoT Hub resource type, see IoT Hub in the Azure Monitor Logs table reference.

For a reference of all Azure Monitor Logs / Log Analytics tables, see the Azure Monitor Log Table Reference.

See Also