Should azure core add InstrumentationPolicy by default whenever azure core httpclient is used

[heyams]

We have a customer who used azure core http client and tracing failed to work.
The workaround was to add HttpPolicyProviders.addAfterRetryPolicies(policies) to their azure core HttpClient instance.
Then it started working as expected.

public static void addAfterRetryPolicies(List<HttpPipelinePolicy> policies) {
        policies.add(new InstrumentationPolicy());
        addPolices(policies, AFTER_PROVIDER);
}

Should azure-core handled this automatically? or have a doc somewhere along with azure core HttpClient emphasizing the fact that InstrumentationPolicy is mandatory in order for the instrumentation to work.

[github-actions]

Thank you for your feedback. Tagging and routing to the team member best able to assist.

[lmolkova]

Context:

• original HTTP client instrumentation is suppressed in scope of Azure HttpClient
• when a plain client without instrumentation policy is used it suppresses the original client, but does not add instrumentation
• we can't add instrumentation policy by default because we don't know at which position it should be; logging policy has to be after it; logging is added explicitly

Solutions:

• just document the behavior and ask to call addAfterRetryPolicies
• short-term: change how suppression works - needs to react to context set by instr policy
• long term: get rid of instrumentation policy alltogether and rely on underlying client instrumentation. Need changes in otel spec.

[lmolkova]

I'm going to implement

short-term: change how suppression works - needs to react to context set by instr policy

Azure-core will need to coordinate with OpenTelemetry agent and change how HTTP suppression works so that we can turn off SDK instrumentation, but keep underlying HTTP spans coming from OTel agent coming.

Targeting the next azure-core release in early November