anonymous_github/docs/cache-performance-report.html

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<h2>Keep shared-cache rollout disabled for now</h2>
<p>The current cache slows small and medium warm reads. Large files benefit. A benchmark-only SQLite change identifies a substantial part of the overhead.</p>
<label for="metric">Compare warm changed-text responses</label><br><select id="metric"><option value="serial:p50Ms">Median latency · 1 client · milliseconds</option><option value="concurrent8:p95Ms">p95 latency · 8 clients · milliseconds</option><option value="concurrent8:requestsPerSecond">Throughput · 8 clients · requests/second</option><option value="concurrent8:cpuMsPerRequest">CPU · 8 clients · milliseconds/request</option><option value="concurrent8:peakRssMiB">Peak sampled process memory · MiB</option></select>
<table aria-label="Warm cache benchmark comparison"><thead><tr><th>File / baseline</th><th>Baseline</th><th>Current<br>shared cache</th><th>Experimental<br>SQLite NORMAL</th></tr></thead><tbody id="rows"></tbody></table>
<p class="note muted">16 and 256 KiB: raw source cache with repeated transformation and gzip. 2 MiB: existing transformed-file cache. Two warm batches per setting: 32 serial requests or 64 requests at concurrency eight. CPU and memory include both server and benchmark client.</p>
<ul><li><strong>Correctness:</strong> 2,700 HTTP responses passed byte checks.</li><li><strong>Admin scaling:</strong> one pool statistics query reached 78.7 ms p95 at 100,000 synthetic blob records. It blocks the event loop.</li><li><strong>Eviction:</strong> the 4 MiB limit held, but cycling over a 6.25 MiB working set caused 300 misses in 300 reads.</li><li><strong>Next steps:</strong> reduce metadata commits, cache admin aggregates, and test a representative mixed workload across server processes.</li></ul>
<p class="note">NORMAL was tested only on temporary cache indexes. In WAL mode it can lose recent commits after power loss, so recovery needs validation before adoption. <a href="https://www.sqlite.org/pragma.html#pragma_synchronous">SQLite durability documentation</a>.</p>
<p class="note muted">Local compiled-code evaluation · Node 24.14.1 · 2 November 2026. Shared host, synthetic content, warm filesystem cache, no TLS or production traffic. These measurements are not production capacity guarantees. Application settings remain unchanged.</p>
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