spec-5.50: CR read-path profile (measure-only harness + TAP) — DRAFT pre-merge CI evidence, do not merge#9
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spec-5.50: CR read-path profile (measure-only harness + TAP) — DRAFT pre-merge CI evidence, do not merge#9sqlrush wants to merge 7 commits into
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June 24, 2026 00:00
…nominator) Cross-backend / cross-worker CR construction redundancy from counter deltas: redundancy = construct_delta / distinct_cr_keys (the exact 5-field CR key, never distinct_blocks). Rows with unproven key stability (key_stable != 1) or zero distinct keys read INCONCLUSIVE and never feed the value gate. Pure post-processing: no DB, no product code, no catalog. --self-test runs the U3 math cases (7/7) with no cluster. Spec: spec-5.50-cr-read-path-profile.md
…elta Sample the 17 CR counters already exposed by the shipped pg_cluster_state SRF (category='cr') and compute pre/post deltas. Reuses the existing SRF only: no new SRF/view/column, so catversion does not bump. sample mode fails loud if the cr row count is not 17 (enable-cluster off / drift). --self-test covers the delta join math with no DB. Spec: spec-5.50-cr-read-path-profile.md
t/291: single cluster-enabled node, cr_gate_no_peer_fastpath=off, same-node own-instance CR (not by-construction). L1 proves real undo-chain CR (chain_walk>0). L2 axis A: N independent readers share read_scn (proven via cluster_scn_current; exported-snapshot import fail-closes in cluster mode), cross-backend construct redundancy ~= N, base_page_lsn settles after warm-up (dedup-able steady state). L3 axis B: deeper chain costs more walk + cache evict thrash. L4 axis C: parallel workers inherit leader read_scn, seqscan mutual-exclusion redundancy ~= 1. L5 base_page_lsn over-miss. L6 resolver live-slot shortcut characterisation. L7 FX2 single-node real chains. L8 measure-only guard (no corruption, no cross-instance leak). Perf tier, not fast-gate. No product code, no catalog. Spec: spec-5.50-cr-read-path-profile.md
Self-contained perf-tier driver: brings up a single cluster-enabled node (cr_gate_no_peer_fastpath=off, own-instance CR), drives axis A (SELECT-heavy cross-backend redundancy via staggered snapshot-sharing readers), axis B (long-snapshot deep chain-walk cost), axis C (parallel-scan mutual-exclusion), samples the 17 cr counters pre/post + wall time, emits CSV and runs cr-redundancy-calc. REPORT-ONLY: absolute timings only meaningful on a clean Linux release build (perf workflow); redundancy ratios are build-invariant. No product code, no catalog. Spec: spec-5.50-cr-read-path-profile.md
Add a warn-only Linux step running scripts/perf/run-cr-profile.sh against the candidate install, collected as a perf artifact. Perf tier only (not fast-gate, not a nightly correctness shard; t/291 runs via local make check + here). Build-invariant counter deltas / redundancy are meaningful; absolute wall is cassert-inflated trend (perf.yml is all-cassert). Spec: spec-5.50-cr-read-path-profile.md
…5.8 collision) Session B (spec-5.8) reserves t/291 for the LMD cross-node deadlock 2-node test. Move the CR read-path profile to the 300-block (CR Read-Path band 5.50-5.58 -> t/300+), clear of the deadlock band's 29x range. Perf tier, runs via local make check + perf workflow (not a nightly correctness shard). Spec: spec-5.50-cr-read-path-profile.md
fast-gate comment-headers check requires 'Author: SqlRush' on newly-added cluster TAP files. Add the header block to t/300_cluster_5_50_cr_profile.pl. Spec: spec-5.50-cr-read-path-profile.md
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DRAFT — pre-merge fast-gate evidence only. DO NOT MERGE, DO NOT TAG.
spec-5.50 (Stage 5.5 CR read-path profile), measure-only: adds a CR read-path profile harness + a real own-instance CR-path TAP. Zero product code, zero catalog (catversion unchanged) — diff is
scripts/perf/*+cluster_tap/t/300+perf.ymlonly.scripts/perf/cr-redundancy-calc.{sh,awk}— CR construction redundancy calc (self-test 7/7)scripts/perf/cr-counter-sample.sh— pg_cluster_state CR counter sampler + delta (self-test 2/2)scripts/perf/run-cr-profile.sh— self-contained 3-axis profile driversrc/test/cluster_tap/t/300_cluster_5_50_cr_profile.pl— real own-instance CR path (19/19).github/workflows/perf.yml— warn-only Linux profile step (perf tier, not fast-gate)Local verification: cluster_unit 106/106, t/300 19/19, harness self-tests 9/9. The Validate jobs comment-headers + format checks pass.
NOTE on red CI: the
Validatejob is red due to a pre-existing CI issue unrelated to this change — the commit-message lint runsgit log -1on thepull_requestsynthetic merge commit ("Merge X into Y"), which never matches the conventional-commit pattern, so it blocks the dependent build/test jobs. On a normal push-to-main (the real merge path) the lint sees the real commit and passes. Tracked as a separate main-side CI hardening item; intentionally NOT fixed from this measure-only branch.Merge is intentionally deferred behind the Stage 5 deadlock-band release order; final merge will rebase onto then-current main and re-run the gates via push (not PR), per CI policy.
Spec: spec-5.50-cr-read-path-profile.md