`OTEL_SDK_DISABLED` in v2 is not working the same way as v1

[rmachado-studocu]

Note

TL;DR
OTEL_SDK_DISABLED behaves differently in v2 of @vercel/otel

If you are using this environment variable to enable/disable OpenTelemetry's SDK (and even @vercel/otel's start()), change the usage of "false" (or "0") to "".

In v2's @vercel/otel, the package evaluates OTEL_SDK_DISABLED as "if it is set, it is disabled, if it is not set (or is empty string), it is enabled".

In v1's case, because it made use of the removed parseEnvironment function from OpenTelemetry, it would evaluate the value as a boolean.
This means that OTEL_SDK_DISABLED=true and OTEL_SDK_DISABLED=false would evaluate as the boolean value of true or false:

• OTEL_SDK_DISABLED set as boolean variable in OpenTelemetry v1.30.1
• Then it proceeds to parse it as a boolean
• Which in the end would evaluate the value against 'true'

Now v2 is doing Boolean(env.OTEL_SDK_DISABLED). Meaning that Boolean("false") === true.

My take on this is that either @vercel/otel should backport parseEnviroment's functionality or at least state it as a breaking change, at least for those using this ENV variable, given that it disables completely the SDK whether you set it to "false" or "true" (old values).

In any case, setting it to "" instead of "false" should do the trick

[niuhf0452]

I met the same problem. I think OTEL_SDK_DISABLED should be aligned with otel doc: https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/