{
  "context": "Tests whether the agent correctly diagnoses libuv thread pool saturation caused by dns.lookup() and large file readFile(), replaces them with thread-pool-avoiding alternatives (dns.resolve4, streaming), and configures UV_THREADPOOL_SIZE correctly before Node.js starts rather than at runtime.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "dns.resolve4 instead of dns.lookup",
      "description": "fixed-service.js uses `dns.resolve4()` (or `dns.promises.resolve4()` or another `dns.resolve*` method) instead of `dns.lookup()` for hostname resolution",
      "max_score": 14
    },
    {
      "name": "No dns.lookup in fixed code",
      "description": "fixed-service.js does NOT contain any call to `dns.lookup()` or `dns.promises.lookup()`",
      "max_score": 10
    },
    {
      "name": "Streaming for large file",
      "description": "fixed-service.js uses a streaming approach (e.g., `createReadStream`, `pipeline`, or async iteration over a stream) to read the large config/data file, NOT `readFile()` or `promises.readFile()`",
      "max_score": 12
    },
    {
      "name": "UV_THREADPOOL_SIZE in startup script",
      "description": "start.sh sets UV_THREADPOOL_SIZE as an environment variable before `node` starts (e.g., `UV_THREADPOOL_SIZE=N node service.js` or `export UV_THREADPOOL_SIZE=N` before the node command)",
      "max_score": 14
    },
    {
      "name": "UV_THREADPOOL_SIZE value > 4",
      "description": "The UV_THREADPOOL_SIZE value set in start.sh is greater than 4 (the default), appropriate for an I/O-heavy service",
      "max_score": 8
    },
    {
      "name": "No runtime process.env assignment",
      "description": "fixed-service.js does NOT contain `process.env.UV_THREADPOOL_SIZE = ...` (setting the value at runtime, which has no effect)",
      "max_score": 14
    },
    {
      "name": "monitorEventLoopDelay used",
      "description": "monitoring.js uses `monitorEventLoopDelay` from `node:perf_hooks` (or `perf_hooks`) to measure event loop lag",
      "max_score": 14
    },
    {
      "name": "p99 latency check",
      "description": "monitoring.js reads the p99 percentile from the histogram (calls `.percentile(99)`) as an indicator of thread pool saturation",
      "max_score": 14
    }
  ]
}