Error Handling Strategy

Status

Accepted (2024-02)

Context

LLM operations can fail due to:

• Authentication issues.

• Rate limiting.

• Network errors.

• Content filtering.

• Invalid inputs.

Decision

Implement hierarchical exception system:

Key features:

• All provider errors extend ProviderException (itself a RuntimeException).

• FallbackChainExhaustedException is raised by FallbackMiddleware when every provider in the chain fails (ADR-021, ADR-026).

• ProviderResponseException carries the offending HTTP status and a sanitised message (secrets stripped by ErrorMessageSanitizerTrait).

• Exceptions include provider context.

Consequences

Positive:

• ●● Granular error handling.

• ● Provider-specific recovery strategies.

• ● Clear exception hierarchy.

• ● Actionable error information.

Negative:

• ◑ Many exception classes.

• ◑ Exception handling complexity.

• ✕ Breaking changes in new versions.

Net Score: +5.0 (Positive impact - robust error handling enables graceful recovery strategies)