[Bug] Proxy gRPC telemetry maps invalid language metadata to INTERNAL

[Aias00]

Runtime platform environment

All platforms; reproduced by a unit test on the current develop branch.

RocketMQ version

develop at e3458616d207ee636b1762f0f8dcf788a590d59d.

Describe the Bug

ContextInitPipeline copies the client-controlled gRPC language metadata into ProxyContext without validation. ClientActivity later calls LanguageCode.valueOf(ctx.getLanguage()) while registering producer and consumer channels.

An unknown language therefore throws IllegalArgumentException. The telemetry exception handler converts it to gRPC INTERNAL, so malformed client input is reported as a server failure.

Steps to Reproduce

1. Create a producer Settings telemetry command.
2. Set the context language to UNKNOWN_LANGUAGE.
3. Submit it to ClientActivity.telemetry.
4. Observe gRPC status INTERNAL.

Expected Behavior

Invalid or missing language metadata is rejected as a client-input error (INVALID_ARGUMENT) before channel registration.

Actual Behavior

The request receives INTERNAL.

Proposed Fix

Centralize LanguageCode parsing in ClientActivity, convert invalid values to GrpcProxyException with a bad-request code, and add regression coverage for the telemetry path.

[RockteMQ-AI]

Issue Evaluation

Category: bug | Status: Needs Verification

Thank you for reporting this issue. To help verify and fix it, please provide:

• Version/tag where this occurs
• Steps to reproduce
• Expected vs actual behavior
• Relevant logs or stack traces

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Automated evaluation by github-manager-bot

[Aias00]

Verified on develop at e3458616d207ee636b1762f0f8dcf788a590d59d (before the proposed fix).

Steps to reproduce

1. Create a gRPC telemetry context whose language metadata is an unknown value, for example NOT_A_LANGUAGE.
2. Invoke ClientActivity.heartbeat(...) (the added ClientActivityTest#testInvalidLanguageIsReportedAsInvalidArgument does this deterministically).

Expected behavior

Invalid client metadata is rejected as a client-input error: Code.BAD_REQUEST, which the gRPC layer maps to INVALID_ARGUMENT.

Actual behavior

LanguageCode.valueOf(ctx.getLanguage()) throws IllegalArgumentException. It is not translated to GrpcProxyException, so the gRPC layer returns INTERNAL.

Evidence

The regression test failed against the commit above with: expected:<INVALID_ARGUMENT> but was:<INTERNAL>. PR #10891 adds the reproducer and translates blank/unsupported language metadata to Code.BAD_REQUEST.

[RockteMQ-AI]

Thank you for the detailed verification, @Aias00! The test evidence clearly confirms that invalid language metadata throws IllegalArgumentException instead of being translated to INVALID_ARGUMENT.

I see that PR #10891 already addresses this with proper error code translation and a regression test. Since a fix is already in progress, I will not generate a duplicate PR.

Status: Fix in progress via PR #10891 — closing the loop on this evaluation.

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Automated follow-up by RockteMQ-AI