{ "evaluation_id": "EVAL-20260318-162216", "question_id": "EVAL-20260318-162216", "question_text": "Your Node.js API is responding with 502 errors under load. Here's the relevant code and infrastructure:\n\n- Express.js API behind an Nginx reverse proxy\n- Connection pool to PostgreSQL (max 20 connections)\n- Average response time: 50ms normally, 30s+ during incidents\n- Error logs show: \"connect ETIMEDOUT\" and \"too many clients already\"\n- The issue starts when traffic exceeds 200 req/s\n\n```javascript\napp.get('/api/users/:id', async (req, res) => {\n const client = await pool.connect();\n const result = await client.query('SELECT * FROM users WHERE id = $1', [req.params.id]);\n res.json(result.rows[0]);\n});\n```\n\nWhat's wrong? Provide the fix and explain the connection pool exhaustion pattern.", "category": "code", "timestamp": "2026-03-18T16:22:16.233Z", "display_date": "Mar 18, 2026", "winner": { "name": "GPT-5.4", "provider": "openrouter", "score": 9.97 }, "avg_score": 9.5075, "matrix_size": 56, "models_used": [ { "id": "minimax_m25", "name": "MiniMax M2.5", "provider": "openrouter" }, { "id": "minimax_m21", "name": "MiniMax M2.1", "provider": "openrouter" }, { "id": "minimax_m2", "name": "MiniMax M2", "provider": "MiniMax" }, { "id": "minimax_m1", "name": "MiniMax M1", "provider": "openrouter" }, { "id": "minimax_01", "name": "MiniMax-01", "provider": "openrouter" }, { "id": "judge_claude_sonnet", "name": "Claude Sonnet 4.6", "provider": "openrouter" }, { "id": "judge_gpt54", "name": "GPT-5.4", "provider": "openrouter" }, { "id": "minimax_m27", "name": "MiniMax M2.7", "provider": "openrouter" } ], "rankings": { "judge_gpt54": { "display_name": "GPT-5.4", "provider": "openrouter", "average_score": 9.97, "score_count": 7, "min_score": 9.8, "max_score": 10, "rank": 1 }, "judge_claude_sonnet": { "display_name": "Claude Sonnet 4.6", "provider": "openrouter", "average_score": 9.88, "score_count": 7, "min_score": 9.35, "max_score": 10, "rank": 2 }, "minimax_m25": { "display_name": "MiniMax M2.5", "provider": "openrouter", "average_score": 9.65, "score_count": 7, "min_score": 9, "max_score": 10, "rank": 3 }, "minimax_m1": { "display_name": "MiniMax M1", "provider": "openrouter", "average_score": 9.64, "score_count": 7, "min_score": 8.55, "max_score": 10, "rank": 4 }, "minimax_m2": { "display_name": "MiniMax M2", "provider": "MiniMax", "average_score": 9.51, "score_count": 7, "min_score": 8.8, "max_score": 10, "rank": 5 }, "minimax_m27": { "display_name": "MiniMax M2.7", "provider": "openrouter", "average_score": 9.26, "score_count": 7, "min_score": 8, "max_score": 10, "rank": 6 }, "minimax_01": { "display_name": "MiniMax-01", "provider": "openrouter", "average_score": 9.11, "score_count": 7, "min_score": 8.25, "max_score": 10, "rank": 7 }, "minimax_m21": { "display_name": "MiniMax M2.1", "provider": "openrouter", "average_score": 9.04, "score_count": 7, "min_score": 8.4, "max_score": 9.6, "rank": 8 } }, "judgments": [ { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.8, "brief_justification": "Accurately identifies the connection leak (missing release), explains the exhaustion cascade with visual timing diagrams, provides two practical fix options with code, and adds valuable Nginx/Express tuning recommendations for preventing similar issues." }, { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 8.4, "brief_justification": "Correctly identifies the connection leak as the root cause and provides valid fixes using both manual release and pool.query() patterns. The explanation of the exhaustion pattern is clear and actionable, though the final code example is cut off and could benefit from deeper coverage of Nginx/PostgreSQL interaction details." }, { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 8.8, "brief_justification": "Correctly identifies the connection leak as the primary issue and explains the cascade effect of slow queries exhausting the pool, with accurate mathematical modeling of the exhaustion pattern and comprehensive solutions across application, database, and infrastructure layers." }, { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 9.8, "brief_justification": "The response accurately identifies the connection leak as the root cause, provides three practical fix options with code examples, thoroughly explains the connection pool exhaustion cascade pattern with visual diagrams, and offers actionable production recommendations including PgBouncer for high-load scenarios." }, { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 9.45, "brief_justification": "The response accurately diagnoses connection pool exhaustion due to missing connection release, provides the correct fix using pool.query(), and explains the cascading failure pattern well. Minor deduction for not mentioning the alternative fix (manual release in finally block) that would still work with pool.connect()." }, { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.8, "brief_justification": "Excellent response that accurately identifies the connection leak, provides multiple correct fixes with clear explanations, covers the full failure cascade, offers practical configuration guidance, and includes capacity planning math - highly actionable for an engineer debugging this issue." }, { "judge_key": "minimax_m27", "judge_name": "MiniMax M2.7", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 9.8, "brief_justification": "The response accurately identifies the connection leak bug (not calling client.release()), provides both immediate and optimal fixes, explains the cascading pool exhaustion failure sequence with clear cause-and-effect reasoning, and includes practical monitoring/recommendations. The mathematical breakdown of why 200 req/s triggers the issue is particularly insightful." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 10, "brief_justification": "Response correctly identifies the connection leak (missing client.release()), provides multiple working fixes including best-practice pool.query() approach, thoroughly explains the exhaustion pattern with visual timeline, and includes monitoring, prevention, and wrapper patterns for comprehensive solution." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 9.4, "brief_justification": "Correctly identifies the connection leak as the root cause and provides accurate fixes using try/finally or pool.query(). Explains the exhaustion pattern clearly with a diagram. Slight deduction for completeness as monitoring strategies could be mentioned, but the core problem and solutions are thoroughly addressed." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 9.8, "brief_justification": "Correctly identifies the connection leak as the primary issue and provides a comprehensive fix using try-finally pattern. Explains the exhaustion mechanism clearly with mathematical reasoning and offers practical optimizations across application, database, and proxy layers. Slightly less depth on advanced solutions like PgBouncer, but otherwise thorough." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 10, "brief_justification": "Response correctly identifies the connection leak (missing client.release()) as root cause, provides multiple valid fixes (pool.query(), try/finally, PgBouncer), and thoroughly explains the cascade failure pattern from pool exhaustion through Nginx proxy timeout to 502 errors. Well-structured with clear code examples and diagrams." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 9.4, "brief_justification": "Correctly identifies the connection leak (missing pool.release()) and provides the proper fix using pool.query(). Well-structured with thorough explanation of the exhaustion pattern and actionable recommendations. Minor deduction for not mentioning the try-finally alternative for manual connection handling scenarios." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 10, "brief_justification": "Response correctly identifies the connection leak as root cause, provides proper fix with try/finally, explains the exhaustion cascade clearly, and offers comprehensive additional guidance including pool.query() alternative, configuration tuning, monitoring, and capacity planning." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "Accurately identifies the connection leak as root cause, provides correct fixes (finally block and pool.query), thoroughly explains the exhaustion cascade pattern, and offers valuable additional recommendations for monitoring and prevention." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 9.6, "brief_justification": "Excellent diagnosis identifying the connection leak; provides multiple valid fixes with clear code examples, visual diagrams, and production-ready patterns. Minor deduction for incomplete pool sizing section." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.8, "brief_justification": "Accurately diagnoses the connection pool leak, provides clear code fixes with explanations, and includes valuable additional recommendations for production deployment. The visual diagram and table effectively illustrate the exhaustion pattern." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 10, "brief_justification": "Comprehensive and accurate diagnosis identifying the connection leak as primary issue, with cascading effects explained. Provides correct fix using try-finally pattern and multi-layered optimizations across code, pool config, database, and nginx. Mathematical explanation of exhaustion pattern is insightful and actionable." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 10, "brief_justification": "Excellent response that correctly identifies the missing client.release() as the root cause, thoroughly explains the connection pool exhaustion cascade leading to 502 Nginx errors, and provides multiple practical solutions with clear code examples, visual diagrams, and additional recommendations for monitoring and scaling." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 10, "brief_justification": "Excellent technical diagnosis identifying the connection leak (missing client.release()) and providing the correct fix using pool.query(). Thorough explanation of the exhaustion pattern with actionable recommendations for infrastructure tuning and monitoring." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 10, "brief_justification": "Comprehensive and accurate diagnosis of the connection leak bug with multiple proper solutions, clear visual explanations of the failure cascade, production-ready code patterns, and valuable extras including pool configuration, monitoring, and capacity planning." }, { "judge_key": "minimax_m21", "judge_name": "MiniMax M2.1", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "Perfectly identifies the connection leak bug, provides both immediate and optimal fixes, explains the cascade from connection exhaustion to 502s, and includes quantitative analysis of the 200 req/s threshold with additional monitoring recommendations." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 9, "brief_justification": "Excellent response that correctly identifies the connection pool exhaustion root cause, provides multiple working solutions with clear explanations, and includes comprehensive monitoring strategies. The visual timeline and step-by-step breakdown make the technical concepts highly accessible." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 10, "brief_justification": "Excellent diagnosis identifying the connection pool leak, comprehensive fixes with multiple approaches, clear visual explanations of the exhaustion pattern, and valuable additional recommendations for infrastructure tuning." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 9.4, "brief_justification": "The response correctly identifies the connection leak as the root cause and provides accurate fixes (try/finally with release, and pool.query). It explains the pool exhaustion pattern clearly and offers practical recommendations, though the last code example appears truncated and more depth on infrastructure tuning could strengthen it." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 9.8, "brief_justification": "The response accurately identifies the connection leak as the root cause and provides correct, actionable fixes (pool.query() and manual release with try/finally). It thoroughly explains the pool exhaustion cascade, provides architectural solutions like PgBouncer, and includes practical recommendations. The only minor issue is the health check endpoint code appears slightly incomplete at the end, but the core explanation is excellent." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 9.6, "brief_justification": "The response accurately identifies the core issue (connections not being released from the pool) and provides the correct fix (using pool.query() instead of manually managing connections). It explains the connection exhaustion pattern well and offers practical, actionable solutions with code examples, though it could have mentioned the try-finally pattern for transaction scenarios." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 10, "brief_justification": "The response correctly identifies the connection leak as the root cause, provides accurate fixes with try/finally and pool.query() alternatives, thoroughly explains the exhaustion cascade, and includes comprehensive recommendations for configuration, monitoring, and scaling." }, { "judge_key": "minimax_m2", "judge_name": "MiniMax M2", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "Response correctly identifies the connection leak as root cause, provides accurate fixes with code examples, thoroughly explains the pool exhaustion cascade including why 200 req/s triggers it, and offers practical additional recommendations for monitoring and configuration." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 9.4, "brief_justification": "Correctly identifies the connection leak (missing client.release()) and provides multiple valid fixes. The visual timeline and pattern explanation are excellent. Slight deduction for the abrupt ending that cuts off the pool sizing guide." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.8, "brief_justification": "The response correctly identifies the connection pool leak as the root cause (missing client.release()), explains the exhaustion pattern clearly with visual aids, and provides both the immediate fix and recommended approach (pool.query). Additional recommendations for pool tuning and Nginx configuration add practical value. Depth is slightly reduced as it doesn't mention connection poolers like PgBouncer as a scaling strategy, but covers the essential diagnosis thoroughly." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 9.4, "brief_justification": "Correctly identifies connection pool exhaustion due to unreleased connections and provides accurate fixes (try/finally or pool.query). Well-structured explanation with clear code examples and ASCII diagram. Slight deduction for completeness (could mention Nginx/proxy timeout config) and depth (could explore PgBouncer or connection pooling at scale)." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 10, "brief_justification": "Excellent response that correctly identifies the connection leak as the primary issue, provides a proper fix with try/catch/finally, explains the cascade failure pattern from traffic spikes to 502 errors, and offers actionable optimizations across all layers (application, database, nginx). The mathematical breakdown of connection exhaustion under load is particularly insightful." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 8.65, "brief_justification": "Correctly identifies the connection leak (missing client.release()) and provides the appropriate fix using pool.query(). The explanation of the exhaustion pattern is accurate, though it could mention the alternative try-finally approach for cases requiring transactions. Additional recommendations are helpful but slightly peripheral to the core issue." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 10, "brief_justification": "Accurately identifies the connection leak as root cause, provides complete fix with try/finally pattern, clearly explains the exhaustion cascade with timeline diagrams, and offers comprehensive guidance on pool configuration, Nginx tuning, and capacity planning." }, { "judge_key": "minimax_m1", "judge_name": "MiniMax M1", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "The response correctly identifies the connection leak (missing client.release()), provides both the proper fix (finally block) and optimal solution (pool.query()), explains the cascade failure pattern in detail, and includes practical recommendations for monitoring and configuration. The explanation of why 200 req/s triggers the issue is particularly insightful." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 9.8, "brief_justification": "The response correctly identifies the root cause of the issue, provides multiple solutions with clear code examples, and explains the connection pool exhaustion pattern thoroughly. The only minor area for improvement is a deeper exploration of advanced performance tuning or edge cases." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.8, "brief_justification": "The response provides a comprehensive and accurate diagnosis of the connection pool exhaustion issue, along with clear fixes and insightful recommendations for improving the infrastructure. The only minor area for improvement is a deeper exploration of the interplay between Nginx and Node.js under extreme load." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 9.6, "brief_justification": "The response correctly identifies the root cause of connection pool exhaustion and provides a clear, accurate solution with code examples. It also explains the pattern effectively but could elaborate further on additional edge cases or infrastructure considerations." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 9.8, "brief_justification": "The response correctly identifies the root causes of the issue, provides a clear and accurate fix, explains the connection pool exhaustion pattern in detail, and offers actionable optimizations. It slightly lacks in discussing more advanced edge cases or alternative architectural solutions." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 9.8, "brief_justification": "The response correctly identifies the root cause of the issue, provides clear and actionable solutions, and explains the connection pool exhaustion pattern in detail. However, it could have included more nuanced discussion on edge cases or alternative strategies for handling high load." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 10, "brief_justification": "The response provides a comprehensive and accurate analysis of the problem, explains the root cause of the connection pool exhaustion, and offers detailed fixes with practical code examples. It also includes a thorough explanation of the connection lifecycle and best practices for managing it." }, { "judge_key": "minimax_01", "judge_name": "MiniMax-01", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "The response thoroughly explains the root cause of the issue, provides a clear and accurate fix, and offers a detailed analysis of the connection pool exhaustion pattern, along with actionable recommendations for improvement." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 9, "brief_justification": "The response correctly identifies the missing client.release() as the root cause, provides multiple well-structured fixes (try/finally, pool.query(), wrapper pattern), and explains the exhaustion pattern clearly with a visual timeline. Minor deductions for the truncated pool sizing formula at the end and a slightly inaccurate pool.on('checkout') event signature, but overall an excellent, actionable response." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.35, "brief_justification": "The response correctly identifies the connection leak as the root cause, provides two solid fixes with clear explanations, and includes the exhaustion pattern visualization. The additional recommendations for pool tuning, Nginx configuration, and request timeouts add practical value. Minor note: the math in the visual (200 req/s × 50ms = 10,000 req/500ms) is slightly confusing but doesn't detract significantly." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 8.6, "brief_justification": "The response correctly identifies the connection leak as the root cause and provides both a try/finally fix and the cleaner pool.query() alternative. The explanation of the exhaustion pattern is clear and accurate, with good additional recommendations, though the response appears truncated at the end and could have elaborated more on Nginx configuration and PostgreSQL max_connections tuning." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 9.2, "brief_justification": "The response correctly identifies the connection leak as the primary issue and provides a complete fix with try/finally pattern. The connection pool exhaustion pattern explanation with the mathematical breakdown (Little's Law applied) is particularly insightful, and the additional optimizations covering pool config, DB indexing, and Nginx settings are all practical and actionable." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 9.55, "brief_justification": "The response correctly identifies the missing client.release() as the root cause, provides multiple well-structured fixes with clear code examples, explains the exhaustion cascade pattern thoroughly, and adds valuable production recommendations like PgBouncer, pool tuning, and health checks. Minor deduction for correctness as the Phase 1 diagram shows '20/20 used' which is slightly misleading for normal operation, but overall this is an excellent, actionable response." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 8.25, "brief_justification": "The response correctly identifies the missing client.release() as the root cause and provides the right fix using pool.query(). It explains the exhaustion pattern well, though it could go deeper on additional mitigations like connection timeout configuration, queue limits, or circuit breakers for production resilience." }, { "judge_key": "judge_claude_sonnet", "judge_name": "Claude Sonnet 4.6", "respondent_key": "judge_gpt54", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "The response perfectly identifies the root cause (missing client.release()), provides two levels of fix (try/finally and pool.query), explains the exhaustion cascade with mathematical backing, and includes actionable monitoring/configuration recommendations. Every aspect of the question is addressed accurately and thoroughly." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "minimax_m27", "respondent_name": "MiniMax M2.7", "weighted_score": 8, "brief_justification": "The response correctly identifies the primary bug: leaked PostgreSQL clients due to missing client.release(), and gives appropriate fixes with try/finally or pool.query(). It is clear and practical, but it overstates some details, includes a few questionable/incorrect pg pool monitoring examples, and misses some nuance about how 'too many clients already' can also involve aggregate connections across app instances/processes." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9, "brief_justification": "The response correctly identifies the primary bug: a leaked PostgreSQL client due to missing release, and gives the right fixes with try/finally or pool.query(). It clearly explains the exhaustion pattern and offers practical mitigations, though a few details are slightly imprecise or overgeneralized (for example the concurrency math and some infrastructure advice)." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "minimax_m21", "respondent_name": "MiniMax M2.1", "weighted_score": 8.45, "brief_justification": "The response correctly identifies the core bug: leaked PostgreSQL connections from using pool.connect() without release(), and it proposes the right fix with finally/release or pool.query(). It clearly explains the exhaustion pattern, though the truncated ending and only partial discussion of 502/Nginx behavior and 'too many clients already' prevent a perfect score." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "minimax_m2", "respondent_name": "MiniMax M2", "weighted_score": 9, "brief_justification": "The response correctly identifies the primary bug as a leaked PostgreSQL client due to missing release(), and it explains the pool exhaustion math clearly. It is highly practical and well-structured, though it slightly overstates Nginx timeout behavior as the sole source of 502s and could mention using pool.query() directly for single queries as an even safer fix." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "minimax_m1", "respondent_name": "MiniMax M1", "weighted_score": 8.55, "brief_justification": "The response correctly identifies the primary bug: leaked PostgreSQL connections due to missing client.release(), and gives the right code fixes with try/finally or pool.query(). It is clear and practical, though a few details are slightly overstated or imprecise (for example the exact 502 cause and some pool-state descriptions), so it is not perfect." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "minimax_01", "respondent_name": "MiniMax-01", "weighted_score": 8.4, "brief_justification": "The response correctly identifies the main bug: leaking PostgreSQL pool clients by not releasing them, and provides a valid fix using pool.query plus error handling. It clearly explains the exhaustion/latency pattern, though it could be even stronger by showing the explicit client.release() in a finally block as the alternative manual fix and tying 502s more directly to Nginx upstream timeouts." }, { "judge_key": "judge_gpt54", "judge_name": "GPT-5.4", "respondent_key": "judge_claude_sonnet", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.35, "brief_justification": "The response correctly identifies the primary bug—failing to release PostgreSQL clients—and explains the resulting pool exhaustion and 502 cascade well. It is highly actionable and thorough, though one detail is slightly off: waiting on pool connections does not literally block the Node.js event loop." } ], "meta": { "source": "The Multivac (app.themultivac.com)", "methodology": "10x10 blind peer matrix evaluation", "criteria": "correctness, completeness, clarity, depth, usefulness", "self_judgments": "excluded from rankings", "license": "Open data — cite as: The Multivac (2026)" } }