Monitoring Azure Event Hubs data reference

See Monitoring Azure Event Hubs for details on collecting and analyzing monitoring data for Azure Event Hubs.

Metrics

This section lists all the automatically collected platform metrics collected for Azure Event Hubs. The resource provider for these metrics is Microsoft.EventHub/clusters or Microsoft.EventHub/clusters.

Request metrics

Counts the number of data and management operations requests.

Metric Name Exportable via diagnostic settings Unit Aggregation type Description Dimensions
Incoming Requests Yes Count Total The number of requests made to the Event Hubs service over a specified period. Entity name
Successful Requests No Count Total The number of successful requests made to the Event Hubs service over a specified period. Entity name

Operation Result
Throttled Requests No Count Total The number of requests that were throttled because the usage was exceeded. Entity name

Operation Result

The following two types of errors are classified as user errors:

  1. Client-side errors (In HTTP that would be 400 errors).
  2. Errors that occur while processing messages.

Message metrics

Metric Name Exportable via diagnostic settings Unit Aggregation type Description Dimensions
Incoming Messages Yes Count Total The number of events or messages sent to Event Hubs over a specified period. Entity name
Outgoing Messages Yes Count Total The number of events or messages received from Event Hubs over a specified period. Entity name
Captured Messages No Count Total The number of captured messages. Entity name
Incoming Bytes Yes Bytes Total Incoming bytes for an event hub over a specified period. Entity name
Outgoing Bytes Yes Bytes Total Outgoing bytes for an event hub over a specified period. Entity name
Size No Bytes Average Size of an event hub in bytes. Entity name

Note

These values are point-in-time values. Incoming messages that were consumed immediately after that point-in-time may not be reflected in these metrics.

Capture metrics

Metric Name Exportable via diagnostic settings Unit Aggregation type Description Dimensions
Captured Messages No Count Total The number of captured messages. Entity name
Captured Bytes No Bytes Total Captured bytes for an event hubs Entity name
Capture Backlog No Count Total Capture backlog for an event hubs Entity name

Connection metrics

Metric Name Exportable via diagnostic settings Unit Aggregation type Description Dimensions
Active Connections No Count Average The number of active connections on a namespace and on an entity (event hub) in the namespace. Value for this metric is a point-in-time value. Connections that were active immediately after that point-in-time may not be reflected in the metric. Entity name
Connections Opened No Count Average The number of open connections. Entity name
Connections Closed No Count Average The number of closed connections. Entity name

Error metrics

Metric Name Exportable via diagnostic settings Unit Aggregation type Description Dimensions
Server Errors No Count Total The number of requests not processed because of an error in the Event Hubs service over a specified period. Entity name

Operation Result
User Errors No Count Total The number of requests not processed because of user errors over a specified period. Entity name

Operation Result
Quota Exceeded Errors No Count Total The number of errors caused by exceeding quotas over a specified period. Entity name

Operation Result

Note

Logic Apps creates epoch receivers and receivers may be moved from one node to another depending on the service load. During those moves, ReceiverDisconnection exceptions may occur. They are counted as user errors on the Event Hubs service side. Logic Apps may collect failures from Event Hubs clients so that you can view them in user logs.

Metric dimensions

Azure Event Hubs supports the following dimensions for metrics in Azure Monitor. Adding dimensions to your metrics is optional. If you don't add dimensions, metrics are specified at the namespace level.

Dimension name Description
Entity Name Name of the event hub.

Resource logs

Event Hubs captures diagnostic logs for the following categories:

Category Description
Archive Logs Captures information about Event Hubs Capture operations, specifically, logs related to capture errors.
Operational Logs Capture all management operations that are performed on the Azure Event Hubs namespace. Data operations aren't captured, because of the high volume of data operations that are conducted on Azure Event Hubs.
Auto scale logs Captures auto-inflate operations done on an Event Hubs namespace.
Kafka coordinator logs Captures Kafka coordinator operations related to Event Hubs.
Kafka user error logs Captures information about Kafka APIs called on Event Hubs.
Event Hubs virtual network (VNet) connection event Captures information about IP addresses and virtual networks sending traffic to Event Hubs.
Customer-managed key user logs Captures operations related to customer-managed key.

All logs are stored in JavaScript Object Notation (JSON) format. Each entry has string fields that use the format described in the following sections.

Archive logs schema

Archive log JSON strings include elements listed in the following table:

Name Description
TaskName Description of the task that failed
ActivityId Internal ID, used for tracking
trackingId Internal ID, used for tracking
resourceId Azure Resource Manager resource ID
eventHub Event hub full name (includes namespace name)
partitionId Event Hub partition being written to
archiveStep possible values: ArchiveFlushWriter, DestinationInit
startTime Failure start time
failures Number of times the failure occurred
durationInSeconds Duration of failure
message Error message
category ArchiveLogs

The following code is an example of an archive log JSON string:

{
   "TaskName": "EventHubArchiveUserError",
   "ActivityId": "000000000-0000-0000-0000-0000000000000",
   "trackingId": "0000000-0000-0000-0000-00000000000000000",
   "resourceId": "/SUBSCRIPTIONS/000000000-0000-0000-0000-0000000000000/RESOURCEGROUPS/<Resource Group Name>/PROVIDERS/MICROSOFT.EVENTHUB/NAMESPACES/<Event Hubs Namespace Name>",
   "eventHub": "<Event Hub full name>",
   "partitionId": "1",
   "archiveStep": "ArchiveFlushWriter",
   "startTime": "9/22/2016 5:11:21 AM",
   "failures": 3,
   "durationInSeconds": 360,
   "message": "Microsoft.WindowsAzure.Storage.StorageException: The remote server returned an error: (404) Not Found. ---> System.Net.WebException: The remote server returned an error: (404) Not Found.\r\n   at Microsoft.WindowsAzure.Storage.Shared.Protocol.HttpResponseParsers.ProcessExpectedStatusCodeNoException[T](HttpStatusCode expectedStatusCode, HttpStatusCode actualStatusCode, T retVal, StorageCommandBase`1 cmd, Exception ex)\r\n   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.<PutBlockImpl>b__3e(RESTCommand`1 cmd, HttpWebResponse resp, Exception ex, OperationContext ctx)\r\n   at Microsoft.WindowsAzure.Storage.Core.Executor.Executor.EndGetResponse[T](IAsyncResult getResponseResult)\r\n   --- End of inner exception stack trace ---\r\n   at Microsoft.WindowsAzure.Storage.Core.Util.StorageAsyncResult`1.End()\r\n   at Microsoft.WindowsAzure.Storage.Core.Util.AsyncExtensions.<>c__DisplayClass4.<CreateCallbackVoid>b__3(IAsyncResult ar)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.",
   "category": "ArchiveLogs"
}

Operational logs schema

Operational log JSON strings include elements listed in the following table:

Name Description
ActivityId Internal ID, used for tracking purposes
EventName Operation name. For a list of values for this element, see the Event names
resourceId Azure Resource Manager resource ID
SubscriptionId Subscription ID
EventTimeString Operation time
EventProperties Properties for the operation. This element provides more information about the event as shown in the following example.
Status Operation status. The value can be either Succeeded or Failed.
Caller Caller of operation (Azure portal or management client)
Category OperationalLogs

The following code is an example of an operational log JSON string:

Example:
{
   "ActivityId": "00000000-0000-0000-0000-00000000000000",
   "EventName": "Create EventHub",
   "resourceId": "/SUBSCRIPTIONS/00000000-0000-0000-0000-0000000000000/RESOURCEGROUPS/<Resource Group Name>/PROVIDERS/MICROSOFT.EVENTHUB/NAMESPACES/<Event Hubs namespace name>",
   "SubscriptionId": "000000000-0000-0000-0000-000000000000",
   "EventTimeString": "9/28/2016 8:40:06 PM +00:00",
   "EventProperties": "{\"SubscriptionId\":\"0000000000-0000-0000-0000-000000000000\",\"Namespace\":\"<Namespace Name>\",\"Via\":\"https://<Namespace Name>.servicebus.windows.net/f8096791adb448579ee83d30e006a13e/?api-version=2016-07\",\"TrackingId\":\"5ee74c9e-72b5-4e98-97c4-08a62e56e221_G1\"}",
   "Status": "Succeeded",
   "Caller": "ServiceBus Client",
   "category": "OperationalLogs"
}

Event names

Event name is populated as operation type + resource type from the following enumerations. For example, Create Queue, Retrieve Event Hu, or Delete Rule.

Operation type Resource type
  • Create
  • Update
  • Delete
  • Retrieve
  • Unknown
  • Namespace
  • Queue
  • Topic
  • Subscription
  • EventHub
  • EventHubSubscription
  • NotificationHub
  • NotificationHubTier
  • SharedAccessPolicy
  • UsageCredit
  • NamespacePnsCredentials
  • RuleConsumerGroup

Autoscale logs schema

Autoscale log JSON includes elements listed in the following table:

Name Description
TrackingId Internal ID, which is used for tracing purposes
ResourceId Azure Resource Manager resource ID.
Message Informational message, which provides details about auto-inflate action. The message contains previous and current value of throughput unit for a given namespace and what triggered the inflate of the TU.

Here's an example autoscale event:

{
    "TrackingId": "fb1b3676-bb2d-4b17-85b7-be1c7aa1967e",
    "Message": "Scaled-up EventHub TUs (UpdateStartTimeUTC: 5/13/2021 7:48:36 AM, PreviousValue: 1, UpdatedThroughputUnitValue: 2, AutoScaleReason: 'IncomingMessagesPerSecond reached 2170')",
    "ResourceId": "/subscriptions/0000000-0000-0000-0000-000000000000/resourcegroups/testrg/providers/microsoft.eventhub/namespaces/namespace-name"
}

Kafka coordinator logs schema

Kafka coordinator log JSON includes elements listed in the following table:

Name Description
RequestId Request ID, which is used for tracing purposes
ResourceId Azure Resource Manager resource ID
Operation Name of the operation that's done during the group coordination
ClientId Client ID
NamespaceName Namespace name
SubscriptionId Azure subscription ID
Message Informational or warning message, which provides details about actions done during the group coordination.

Example

{
    "RequestId": "FE01001A89E30B020000000304620E2A_KafkaExampleConsumer#0",
    "Operation": "Join.Start",
    "ClientId": "KafkaExampleConsumer#0",
    "Message": "Start join group for new member namespace-name:c:$default:I:KafkaExampleConsumer#0-cc40856f7f3c4607915a571efe994e82, current group size: 0, API version: 2, session timeout: 10000ms, rebalance timeout: 300000ms.",
    "SubscriptionId": "0000000-0000-0000-0000-000000000000",
    "NamespaceName": "namespace-name",
    "ResourceId": "/subscriptions/0000000-0000-0000-0000-000000000000/resourcegroups/testrg/providers/microsoft.eventhub/namespaces/namespace-name",
    "Category": "KafkaCoordinatorLogs"
}

Kafka user error logs schema

Kafka user error log JSON includes elements listed in the following table:

Name Description
TrackingId Tracking ID, which is used for tracing purposes.
NamespaceName Namespace name
Eventhub Event hub name
PartitionId Partition ID
GroupId Group ID
ClientId Client ID
ResourceId Azure Resource Manager resource ID.
Message Informational message, which provides details about an error

Event Hubs virtual network connection event schema

Event Hubs virtual network (VNet) connection event JSON includes elements listed in the following table:

Name Description
SubscriptionId Azure subscription ID
NamespaceName Namespace name
IPAddress IP address of a client connecting to the Event Hubs service
Action Action done by the Event Hubs service when evaluating connection requests. Supported actions are Accept Connection and Deny Connection.
Reason Provides a reason why the action was done
Count Number of occurrences for the given action
ResourceId Azure Resource Manager resource ID.

Virtual network logs are generated only if the namespace allows access from selected networks or from specific IP addresses (IP filter rules). If you don't want to restrict the access to your namespace using these features and still want to get virtual network logs to track IP addresses of clients connecting to the Event Hubs namespace, you could use the following workaround. Enable IP filtering, and add the total addressable IPv4 range (1.0.0.0/1 - 255.0.0.0/1). Event Hubs IP filtering doesn't support IPv6 ranges. You may see private endpoint addresses in the IPv6 format in the log.

Example

{
    "SubscriptionId": "0000000-0000-0000-0000-000000000000",
    "NamespaceName": "namespace-name",
    "IPAddress": "1.2.3.4",
    "Action": "Deny Connection",
    "Reason": "IPAddress doesn't belong to a subnet with Service Endpoint enabled.",
    "Count": "65",
    "ResourceId": "/subscriptions/0000000-0000-0000-0000-000000000000/resourcegroups/testrg/providers/microsoft.eventhub/namespaces/namespace-name",
    "Category": "EventHubVNetConnectionEvent"
}

Customer-managed key user logs schema

Customer-managed key user log JSON includes elements listed in the following table:

Name Description
Category Type of category for a message. It's one of the following values: error and info. For example, if the key from your key vault is being disabled, then it would be an information category or if a key can't be unwrapped, it could fall under error.
ResourceId Internal resource ID, which includes Azure subscription ID and namespace name
KeyVault Name of the Key Vault resource
Key Name of the Key Vault key that's used to encrypt the Event Hubs namespace.
Version Version of the Key Vault key.
Operation The operation that's performed on the key in your key vault. For example, disable/enable the key, wrap, or unwrap.
Code The code that's associated with the operation. Example: Error code, 404 means that key wasn't found.
Message Message, which provides details about an error or informational message

Here's an example of the log for a customer managed key:

{
   "TaskName": "CustomerManagedKeyUserLog",
   "ActivityId": "11111111-1111-1111-1111-111111111111",
   "category": "error"
   "resourceId": "/SUBSCRIPTIONS/11111111-1111-1111-1111-11111111111/RESOURCEGROUPS/DEFAULT-EVENTHUB-CENTRALUS/PROVIDERS/MICROSOFT.EVENTHUB/NAMESPACES/FBETTATI-OPERA-EVENTHUB",
   "keyVault": "https://mykeyvault.vault-int.azure-int.net",
   "key": "mykey",
   "version": "1111111111111111111111111111111",
   "operation": "wrapKey",
   "code": "404",
   "message": "Key not found: ehbyok0/111111111111111111111111111111",
}



{
   "TaskName": "CustomerManagedKeyUserLog",
   "ActivityId": "11111111111111-1111-1111-1111111111111",
   "category": "info"
   "resourceId": "/SUBSCRIPTIONS/111111111-1111-1111-1111-11111111111/RESOURCEGROUPS/DEFAULT-EVENTHUB-CENTRALUS/PROVIDERS/MICROSOFT.EVENTHUB/NAMESPACES/FBETTATI-OPERA-EVENTHUB",
   "keyVault": "https://mykeyvault.vault-int.azure-int.net",
   "key": "mykey",
   "version": "111111111111111111111111111111",
   "operation": "disable" | "restore",
   "code": "",
   "message": "",
}

Following are the common errors codes to look for when BYOK encryption is enabled.

Action Error code Resulting state of data
Remove wrap/unwrap permission from a key vault 403 Inaccessible
Remove AAD role membership from an AAD principal that granted the wrap/unwrap permission 403 Inaccessible
Delete an encryption key from the key vault 404 Inaccessible
Delete the key vault 404 Inaccessible (assumes soft-delete is enabled, which is a required setting.)
Changing the expiration period on the encryption key such that it's already expired 403 Inaccessible
Changing the NBF (not before) such that key encryption key isn't active 403 Inaccessible
Selecting the Allow MSFT Services option for the key vault firewall or otherwise blocking network access to the key vault that has the encryption key 403 Inaccessible
Moving the key vault to a different tenant 404 Inaccessible
Intermittent network issue or DNS/AAD/MSI outage Accessible using cached data encryption key

Azure Monitor Logs tables

Azure Event Hubs uses Kusto tables from Azure Monitor Logs. You can query these tables with Log Analytics. For a list of Kusto tables the service uses, see Azure Monitor Logs table reference.

Next steps