Monitoring Azure Event Hubs

Introduction to Event Hubs Monitoring

Monitoring is crucial for understanding the health and performance of your Event Hubs. Azure provides comprehensive tools and metrics to help you keep track of your event ingestion, throughput, latency, and consumer activity.

Key aspects to monitor include:

• Ingestion Rate: How many events are being sent to your Event Hub.
• Delivery Count: How many times an event has been delivered to consumers.
• Throttled Requests: Number of requests that were limited due to hitting service quotas.
• Consumer Lag: The difference in time between when an event was published and when it was processed by a consumer.
• Connection Status: Ensuring producers and consumers are successfully connected.

Using Azure Monitor

Azure Monitor is the central service for collecting, analyzing, and acting on telemetry from your Azure and on-premises environments. For Event Hubs, Azure Monitor provides:

Metrics

Navigate to your Event Hubs namespace in the Azure portal. Under the 'Monitoring' section, select 'Metrics'. You can then choose from a wide range of metrics, such as:

• Incoming Messages/Bytes: Tracks the volume of data ingested.
• Outgoing Messages/Bytes: Tracks the volume of data consumed.
• Successful Requests: Number of successful operations.
• Server Errors: Number of errors returned by the service.
• User Errors: Number of errors returned due to client-side issues.

You can visualize these metrics over time, set up alerts, and create dashboards for consolidated views.

Logs (Diagnostic Settings)

To gain deeper insights into specific events and errors, configure diagnostic settings for your Event Hubs namespace. This allows you to send logs to Log Analytics workspaces, Storage Accounts, or Event Hubs itself.

Key log categories to enable:

• OperationalLogs: Captures operations performed on the namespace, such as create, update, delete.
• DiagnosticLogs: Detailed logs for producer and consumer activities, errors, and request/response details.

Once logs are collected in Log Analytics, you can use Kusto Query Language (KQL) to perform complex analysis.

Example KQL Query for Errors:

AzureDiagnostics
| where ResourceProvider == "MICROSOFT.EVENTHUB" and Category == "DiagnosticLogs"
| where ResultType != "Success"
| project TimeGenerated, Resource, OperationName, ResultType, CallerIpAddress, DurationMs, ResponseCode
| order by TimeGenerated desc

Alerting on Key Metrics

Proactive alerting is essential to catch issues before they impact your applications. Azure Monitor Alerts can notify you when specific conditions are met.

Setting up an Alert Rule:

1. In your Event Hubs namespace, go to 'Alerts' under 'Monitoring'.
2. Click 'New alert rule'.
3. Define conditions: Select the signal (metric) you want to monitor, e.g., 'Throttled Requests'. Set the threshold and aggregation type.
4. Define actions: Choose an action group to notify your team via email, SMS, webhook, etc.
5. Define details: Name your alert rule and provide a description.

Common Alerts to Configure:

• High number of throttled requests.
• Significant increase in server errors.
• Low incoming message rate (indicating a potential producer issue).
• High consumer lag.

Monitoring with SDKs and Tools

Beyond the Azure portal, you can integrate monitoring into your applications and use specialized tools.

Application Insights Integration

For applications producing or consuming events from Event Hubs, integrate Application Insights. This provides end-to-end transaction monitoring, performance analysis, and dependency tracking. You can track Event Hubs calls as dependencies.

Event Hubs SDK Metrics

The Azure SDKs for Event Hubs often expose internal metrics related to connection status, batching, and error handling, which can be logged or exposed by your application.

Third-Party Monitoring Tools

Various third-party monitoring solutions can be integrated with Azure Event Hubs to provide unified dashboards and advanced analytics.

Best Practices for Monitoring

• Establish Baselines: Understand your normal traffic patterns and performance metrics.
• Regularly Review Dashboards: Create custom dashboards in Azure Monitor for a quick overview.
• Tune Alert Thresholds: Avoid alert fatigue by setting appropriate and meaningful thresholds.
• Correlate Metrics and Logs: Use metrics to identify anomalies and logs to investigate root causes.
• Monitor Consumer Health: Ensure your consumers are running, processing messages, and not falling behind.
• Track Quota Usage: Keep an eye on Event Hubs quotas (throughput units, ingress/egress limits) to prevent throttling.