The SDK MUST set a default value for the attribute service.name if it was not specified

[srikanthccv]

The service.name attribute of Resource is mandatory and SDK should set the default value if not specified. This attribute is necessary for certain backends such as Jaeger to identify the service that produced the spans.

From specs

The SDK MUST set a default value for the following attributes if they were not specified, even if the resource would otherwise not be present at all:

• service.name

[1]: MUST be the same for all instances of horizontally scaled services. If the value was not specified, SDKs MUST fallback to unknown_service: concatenated with process.executable.name, e.g. unknown_service:bash. If process.executable.name is not available, the value MUST be set to unknown_service.

[codeboten]

This issue is still being discussed here: open-telemetry/opentelemetry-specification#1237

[srikanthccv]

@codeboten This PR open-telemetry/opentelemetry-specification#1269 says it fixes the mentioned issue and it got merged. The issue would have been auto-closed but description formatting prevented that.

[srikanthccv]

It seems there are some updates to spec around this issue. Resource merge behaviour is updated with this PR open-telemetry/opentelemetry-specification#1345.

[srikanthccv]

This is fixed in #1480 hence closing.