json-schema

vLLM JSON output malformed after CUDA upgrade to 12.4

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Problem Description Symptoms and Impact After upgrading the Docker image to CUDA 12.4, vLLM v0.6.3 started emitting malformed JSON for function‑calling prompts. The downstream FastAPI gateway receives a truncated or syntactically invalid JSON payload, which triggers json.JSONDecodeError exceptions and causes request drops. Log snippet from a worker thread: INFO vllm.engine.output_parser – Received partial JSON: {“name”: “search”, “parameters”: … Read more

vLLM JSON deserialization errors during high concurrency testing

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Problem: JSON Deserialization Errors in vLLM Function‑Calling under High Concurrency During sustained load testing of the /v1/chat/completions endpoint with function calling enabled, engineers observed intermittent failures such as: JSONDecodeError: Expecting value: line 1 column 1 (char 0) Tool call response schema validation failed: missing required field ‘name’ vLLM request dropped: JSON parsing error RuntimeError: Failed … Read more

Mistral AI model invoking external API with malformed JSON payload

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Problem: Mistral AI model returns malformed JSON payloads when invoking external APIs during concurrent A/B test traffic splits In a production A/B testing setup, traffic is split between two Mistral model variants: Variant Temperature top_p Observed failure rate A 0.6 0.8 ~2 % B 0.9 0.95 34 % ↑ (SchemaValidationError) Under high concurrency, Variant B frequently produces JSON that: … Read more

PostgreSQL vector search malformed JSON response after RAG pipeline update

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Problem Description After a routine update to the Retrieval‑Augmented Generation (RAG) pipeline, the citation extraction step began returning malformed JSON objects. Downstream the LLM serializer throws errors such as: JSON parsing error: Unexpected token ‘}’ at position 127 ERROR: invalid input syntax for type jsonb Observed symptoms in production logs: API responses missing source_id fields … Read more

Qwen batch processing JSON schema violation errors

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Problem Description When using Qwen’s JSON mode in a batch request, the downstream system receives responses that do not satisfy the predefined JSON schema. Typical symptoms include: Missing required fields (e.g., “id”, “timestamp”) Incorrect data types (e.g., “score” returned as a string instead of a number) Truncated or malformed JSON objects at the end of … Read more