• Package Name: azure-monitor-opentelemetry
• Package Version: 1.3.0
• Operating System: MacOS
• Python Version: 3.10.13

Describe the bug

With default configuration (absence of configuration), time of execution of configure_azure_monitor() takes abnormally long time: ~10 seconds.

To Reproduce

long.py:

import time
from azure.monitor.opentelemetry import configure_azure_monitor

start = time.monotonic()
configure_azure_monitor()
print(time.monotonic() - start)

APPLICATIONINSIGHTS_CONNECTION_STRING="..." python long.py

Expected behavior

Reasonable time to configure (< 1 s).

Additional context

After running in debugger I discovered two main code places contributing to the delay, and both are related to checking the fact of running in an Azure VM.

1. Resource detection.

Location: https://github.com/open-telemetry/opentelemetry-python-contrib/blob/37aba928d45713842941c7efc992726a79ea7d8a/resource/opentelemetry-resource-detector-azure/src/opentelemetry/resource/detector/azure/vm.py#L77

The way code gets there:

Then in https://github.com/open-telemetry/opentelemetry-python-contrib/blob/main/resource/opentelemetry-resource-detector-azure/src/opentelemetry/resource/detector/azure/vm.py

Location:

Call stack:

http://169.254.169.254/metadata/instance/compute
though, to different API versions. The first place has request timeout of 4 seconds, and the second place has 5 seconds, which together constitute almost the entire time of the startup delay.

Workarounds

1. Exclude Azure resource detectors with help of setting OTEL_EXPERIMENTAL_RESOURCE_DETECTORS=otel environment variable. If not set, the library sets the default value, that includes App Service and Azure VM.
2. Disable sending statsbeat using APPLICATIONINSIGHTS_STATSBEAT_DISABLED_ALL=TRUE

The above tweaks bring the configuration time down to ~0.8 s (and with OTEL_PYTHON_DISABLED_INSTRUMENTATIONS set to azure_sdk,django,fastapi,flask,psycopg2,requests,urllib,urllib3 it completes under 30 ms).

It took me hours to find the above options for fixing the startup time without touching the code. I think we need to make the library friendlier to running in non-Azure environments.