Announcing the General Availability of Azure Load Balancer Health Event Logs

Health event logs are now fully available in all public, Azure China, and Government regions under the Azure Monitor resource log category LoadBalancerHealthEvent, providing you with enhanced capabilities to monitor and troubleshoot your load balancer resources.

Health Event Types

As announced in our previous public preview blog, the following health events are now logged when detected by the Azure Load Balancer platform. These events are designed to address the most critical issues affecting your load balancer’s health and availability:

Benefits of Using Health Event Logs

Health event logs provide deeper insights into the health of your load balancer, eliminating the need to set thresholds for metric-based alerts or manage complex metric data for historical analysis. Here’s how you can get started using these logs today:

1. Create Diagnostic Settings: Archive or analyze these logs for long-term insights.
2. Leverage Log Analytics: Use powerful querying capabilities to gain detailed insights.
3. Configure Alerts: Set up alerts to trigger actions based on the generated logs.

For more detailed instructions on how to enable and use health event logs, refer to our documentation here.

Contoso’s Story

Context: Contoso uses a Standard Public Load Balancer with outbound rules to connect their application to public APIs. They allocate 8k ports to each backend instance using an outbound rule, anticipating up to 8 backend instances in a pool.

Problem: Contoso is concerned about SNAT port exhaustion and wants to create alerts to warn them if backend instances are close to consuming all allocated SNAT ports.

Solution with metrics: Initially, they create an alert using the Used SNAT ports metric, triggering when the value exceeds 6k ports (out of 8k). However, this requires constant adjustment as they scale their infrastructure and update port allocation on outbound rules.

Solution with health event logs: With the new health event logs, Contoso configures two alerts:

1. HighSnatPortUsage: Sends an email and creates an incident whenever this event is generated, warning network engineers to allocate more SNAT ports.
2. SnatPortExhaustion: Notifies the on-call engineer immediately to address critical impact to outbound connectivity due to lack of SNAT ports.

Now, Contoso no longer needs to adjust alert rules as they scale, ensuring seamless monitoring and response.

What’s Next?

This general availability announcement marks a significant step in enhancing the health and monitoring capabilities of Azure Load Balancer. We are committed to expanding these capabilities with additional health event types, providing configuration guidance, best practices, and warnings for service-related limits.

We welcome your feedback and look forward to hearing about your experiences with health event logs. Get started today by exploring our public documentation.

Stay tuned on Azure Updates for future announcements and enhancements!