Azure Functions: Same Codebase Logging Works in One Environment but Not in Others

Question

The same codebase using logging.info worked in my environment—I was able to track logs. However, the same codebase didn’t produce logs in other environments. Both azure function environment created in elastic premium

Answer 1

When logging works in one Azure Functions environment but not in others, there are several factors to consider:

1. Configuration Differences: Ensure that the host.json file and application settings are consistent across environments. Log levels and categories can be configured in host.json, and differences here can lead to discrepancies in logging behavior.
2. Application Insights Configuration: Verify that Application Insights is properly set up in all environments. If the Application Insights SDK is not configured correctly, it may not send logs to the portal. Make sure that the necessary packages are installed and that the telemetry is being initialized correctly in your startup configuration.
3. Network Issues: If your function app is integrated with a virtual network, ensure that the necessary outbound ports are open for Application Insights to send data. Specifically, port 443 must be allowed for outgoing traffic.
4. Log Volume and Verbosity: Check if the log volume and verbosity settings are different across environments. You can control the amount of logging by adjusting the log level settings in the host.json file or through application settings.
5. Thread Logging: If your function creates threads, ensure that you are passing the context parameter correctly to maintain the logging context. This is crucial for capturing logs from threads accurately.

By reviewing these aspects, you should be able to identify why logging behaves differently across your Azure Functions environments.

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References:

• Monitor executions in Azure Functions
• Logging
• Control volume and verbosity of logs