[cristim]

Closes #394.

Problem

findFamilyRates (providers/gcp/services/computeengine/pricing.go) accepted RAM SKUs only in GiBy.h and refused any other unit. C4D RAM SKUs, on-demand and commitment, are priced in GBy.h. So:

• every C4D recommendation lost its pricing and savings percentage (the enrichment path only logs);
• GetOfferingDetails failed for C4D.

Evidence (public Cloud Billing Catalog, Compute Engine service, read 2026-11-08)

• GBy.h ("gigabyte hour") rows have baseUnit By.s and baseUnitConversionFactor 3600000000000, which is 10^9 bytes x 3600 s: a decimal gigabyte-hour. All 572 GBy.h rows carry this factor.
• GiBy.h rows carry 3865470566400, which is 2^30 x 3600. All 7202 GiBy.h rows carry this factor.
• Commitment RAM appears only in those two units: 1927 GiBy.h rows and 176 GBy.h rows (C4D and M4Ultramem224).
• Core/Cpu rows are always h.

Change

• RAM prices are normalized to per GiB-hour through an explicit allowlist: GiBy.h x 1, GBy.h x 2^30/10^9 = 1.073741824. Memory amounts are GiB end to end.
• The conversion happens before the ambiguity check, so duplicate SKUs are compared per GiB.
• Any other RAM unit fails with "unsupported RAM usage unit".
• Core/Cpu pricing and its error text are unchanged.

I chose an allowlist over reading baseUnitConversionFactor because the allowlist fails closed on any unit code it doesn't know, and the live tallies above show both codes always carry the expected factor. This matches cloudstorage's unit handling.

Tests

• TestFindFamilyRates_RAMUsageUnits uses live skuIds and prices:
  • C4D on-demand and 1yr/3yr commitment, with exact converted rates;
  • N2 GiBy.h unchanged;
  • M4Ultramem224 GBy.h at the collector level;
  • MiBy.h, GiBy.mo and an empty unit refused;
  • two RAM SKUs at the same raw price in GiBy.h and GBy.h, which must be reported as ambiguous.
• TestGetComputePricing_C4DGBytePricedRAM runs end to end through the billing mock: the hourly rate equals cores x core rate + GiB x converted RAM rate, and savings are positive.
• The new tests fail on main with the unit error and pass here.
• Mutation probes, each caught: the factor set to 1, the factor inverted, the conversion applied after the ambiguity check, and any unit accepted.

Notes

• M4Ultramem224: stays unreachable through this path, because m4-ultramem-224 maps to the plain M4 label and is priced at M4 rates. Tracked in fix(gcp/computeengine): m4-ultramem-224 is priced at plain M4 rates #719.
• m1/m2: the on-demand catalog ambiguity in three regions is pre-existing, tracked in fix(gcp/computeengine): m1/m2 on-demand pricing is ambiguous in us-east4, asia-southeast1 and asia-northeast1 #720.
• Platform pin: the platform repo pins providers/gcp at 52d66feb616b (main as of 2026-11-09), so this fix reaches it after a pin bump.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Corrected Google Cloud Compute Engine memory pricing so rates billed in decimal gigabytes are converted to the equivalent per-GiB rates. This improves the accuracy of on-demand and committed-use pricing estimates. Existing rates already expressed in GiB remain unchanged, and unsupported memory billing units are now reported as errors.

[coderabbitai]

Walkthrough

RAM rates priced in GBy.h are converted to per-GiB-hour values. CPU prices still require h. Tests cover supported and unsupported RAM units, unit conflicts, and C4D pricing.

Changes: GCP Compute Engine RAM Price Normalization

Layer / File(s)	Summary
Normalize RAM rates and verify C4D pricing providers/gcp/services/computeengine/pricing.go, providers/gcp/services/computeengine/pricing_test.go	RAM rates in GiBy.h and GBy.h are normalized before collection. CPU rates still require h. Tests cover unit conversion, unsupported units, conflicting units, and C4D pricing for on-demand and commitment rates.

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix · Severity of issue fixed: Medium

Possibly related issues

• Issue 719 — It concerns decimal GBy.h RAM pricing, but the family-label mapping that leaves the M4 fallback unreachable is not changed here.
• Issue 720 — It concerns duplicate on-demand prices. This change does not select the legacy SKU involved in that ambiguity.

Merge Risk: Minimal · up to a7074

The RAM unit conversion has no identified merge-blocking issue. Merge after normal checks complete successfully.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff with cyclomatic complexity of at least 2. Documenta…	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title "fix(gcp): price RAM SKUs quoted in decimal GBy.h" names the main change. The PR converts RAM SKU prices quoted in decimal GBy.h to per-GiB-hour rates in providers/gcp/services/computeengine…
Linked Issues check		Directly linked issue #394 requires that C4D commitment RAM SKUs with usage unit GBy.h price instead of failing. It also requires an explicit decision on the unit and verification against a live SKU…
Out of Scope Changes check		The whole-PR diff from merge base 81a709068bbafe2ea6e19e7fd815355e89fa9bc2 to head a70744992c57cf15ebc05c3e0262c5b3f40d96ac changes two files: providers/gcp/services/computeengine/pricing.go and…

Full details: Title check

Explanation

The title "fix(gcp): price RAM SKUs quoted in decimal GBy.h" names the main change. The PR converts RAM SKU prices quoted in decimal GBy.h to per-GiB-hour rates in providers/gcp/services/computeengine/pricing.go, and the objectives confirm this is the core purpose (linked issue #394). The title is short, specific, and follows a conventional commit style. It does not mention the unit rejection or the ambiguity checks, but those are secondary details.

Full details: Linked Issues check

Explanation

Directly linked issue #394 requires that C4D commitment RAM SKUs with usage unit GBy.h price instead of failing. It also requires an explicit decision on the unit and verification against a live SKU. The reviewed head meets the coding requirement. In pricing.go, ramUnitToGiBHour maps GiBy.h to 1 and GBy.h to (1 << 30) / 1e9. rateCollector.add calls normalizedPrice before the currency and ambiguity checks, so RAM prices reach rateSlot.set already per GiB-hour. Any other RAM unit returns unsupported RAM usage unit. pricing_test.go covers C4D on-demand and 1-year/3-year commitment rates with exact converted values, N2 GiBy.h unchanged, M4Ultramem224 GBy.h at collector level, refused units, ambiguity at equal raw price, and end-to-end getComputePricing for C4D. The decimal-GB interpretation matches the issue's stated option. The live-catalog facts (baseUnitConversionFactor values and row tallies) come from the PR description and were not re-read here, because no network inspection is available. The test data is hardcoded live-shaped SKUs, so the tests do not re-verify the catalog at run time. This does not block the coding verdict.

Full details: Out of Scope Changes check

Explanation

The whole-PR diff from merge base 81a709068bbafe2ea6e19e7fd815355e89fa9bc2 to head a70744992c57cf15ebc05c3e0262c5b3f40d96ac changes two files: providers/gcp/services/computeengine/pricing.go and providers/gcp/services/computeengine/pricing_test.go. Every changed hunk serves #394. The usageUnitGiBHour constant is replaced by the ramUnitToGiBHour allowlist. That is a supporting refactor. The new helpers ramPricePerGiBHour and normalizedPrice implement the conversion. Core/CPU handling keeps its h check and error text. The tests exercise the new behavior. The PR's notes on M4Ultramem224 (#719), m1/m2 ambiguity (#720), and the platform pin bump are context, not code changes in this PR. The head merge with main commit 81a7090 falls at the merge base, so it adds no pricing-related delta in the whole-PR diff. No unrelated change was found.

Full details: Docstring Coverage

Explanation

Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff with cyclomatic complexity of at least 2. Documentation-only edits and deletions within surviving functions are included; unchanged diff context and fully deleted functions are excluded. Analyzed 3 functions across 2 files.

Resolution

Write docstrings for the functions missing them to satisfy the coverage threshold.

Finishing Touches

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[cristim]

APPROVED 0c0c918 by claude-darling

Cold review; I did not write this change. Claim from go#394: C4D RAM SKUs use GBy.h, findFamilyRates only accepted GiBy.h, so C4D never priced. I treated the PR body as a claim and checked the code.

Conversion (pricing.go:194-206): price per GB (1e9 bytes) times 2^30/1e9 gives price per GiB. The direction is right: a GiB is 1.0737 GB, so the per-GiB price is higher. It holds if usage is metered in bytes, which is what the catalog's base-unit factors (1e93600 against 2^303600) encode. Memory is GiB end to end (pricing.go:57, :326-327: MB/1024 times the per-GiB rate). I did not query the live catalog; the evidence tallies in the body are the PR's claim.

Edge cases attacked

• Unknown, empty or GiBy.mo/MiBy.h RAM unit: refused with "unsupported RAM unit", fail closed.
• A GiBy.h and a GBy.h SKU at the same raw price are different per-GiB prices, so they are reported ambiguous. The conversion runs before the ambiguity check (pricing.go:232, then rateSlot.set).
• Core/CPU unit check and its error text are unchanged, and a test still pins it.
• Float equality in the ambiguity check only fails closed (identical inputs give identical outputs), never silently prices.
• usageUnitGiBHour has no remaining reference in the package.

Callers

• Changed symbols are unexported, so no exported API changes. The platform reaches pricing only through the generic client (providers/gcp pin in go.mod), so nothing there breaks and it picks the fix up on the next pin bump. The body's pin sha (ad67030387e4) is stale; main pins 52d66feb616b. Cosmetic.

Probes (scoped -run 'FindFamilyRates|GetComputePricing|EnrichRecWithPricing' in providers/gcp/services/computeengine, a scratch copy, each reverted). Green at the head. Every probe fails a real test, none a build error:

• GBy.h factor set to 1: 6 failures.
• Factor inverted: 5 failures.
• Unit allowlist bypassed: 4 failures.
• CPU unit check bypassed: 2 failures.
• GiBy.h factor perturbed: 8 failures.

Full suite: CI on this head, 14 checks SUCCESS and 1 NEUTRAL when I looked. Merge state was BLOCKED, i.e. waiting on approvals.

No actionable findings.

[cristim]

APPROVED 0c0c918 by claude-nibblets

Independent cold second review of #722 (closes #394): one commit on main a52dfb91, 1 behind (81a7090, #714; a trial merge is clean). I read the diff and the surrounding pricing code, ran the tests and probes locally, and treated the PR body as a claim.

The conversion is correct and fails closed

• ramUnitToGiBHour (providers/gcp/services/computeengine/pricing.go:194-198) is an explicit allowlist: GiBy.h x 1 and GBy.h x (1<<30)/1e9, which is 1.073741824. A decimal gigabyte-hour is cheaper per unit than a gibibyte-hour, so a price quoted per GBy.h converts to a higher price per GiB-hour. The direction is right.
• ramPricePerGiBHour returns "unsupported RAM usage unit" for anything not in the map (MiBy.h, GiBy.mo, an empty unit). Core/Cpu pricing and its error text are unchanged.
• Convert before comparing: rateCollector.add calls normalizedPrice before rateSlot.set (pricing.go:228-246). The ambiguity comparison therefore sees per-GiB prices, so a GiBy.h SKU and a GBy.h SKU at the same raw price are correctly reported as ambiguous.
• Consumers: the hourly price is vcpus x cpu + memoryGiB x ram (:326-327), with memory in GiB (memMB/1024), so a per-GiB-hour rate is the unit that formula wants.
• The removed usageUnitGiBHour constant has no other user, since the package builds, vets clean and passes.

Probes (local, ./services/computeengine/ in providers/gcp, under the review lock)

The whole package passes at baseline and go vet is clean. Each probe was killed:

• U1, the GBy.h factor set to 1: killed by TestGetComputePricing_C4DGBytePricedRAM, …RAMUsageUnits/C4D_GBy.h_on_demand_and_commitment_convert_to_per_GiB and …/mixed_units_at_the_same_raw_price_are_ambiguous.
• U2, the factor inverted: killed by the C4D tests, …/helper_converts_per_allowed_unit and …/M4Ultramem224_GBy.h_through_the_collector.
• U3, an unknown unit accepted at factor 1: killed by the three unsupported-unit cases (MiBy.h, GiBy.mo, empty).
• U4, GBy.h removed from the allowlist (the behaviour on main): killed by the C4D, mixed-unit and helper tests.
• U5, the conversion moved after the ambiguity check: killed by the C4D, mixed-unit and M4Ultramem224 tests.

Not independently verified

The body's catalog evidence (every GBy.h row carrying a base-unit factor of 3600000000000, and C4D and M4Ultramem224 being the only commitment RAM in GBy.h) comes from the live Cloud Billing Catalog, which needs an API key I didn't use. The code's choice of an allowlist over reading the factor means a wrong assumption fails closed ("unsupported RAM usage unit") instead of mispricing, which is the right safety property.

Notes (non-blocking)

• Two SKUs whose converted per-GiB prices are mathematically equal but arrive in different units could differ by a float rounding error and be reported ambiguous. That fails closed, and it's a catalog oddity I'd expect never to occur.
• The M4Ultramem224 mapping to the M4 label (fix(gcp/computeengine): m4-ultramem-224 is priced at plain M4 rates #719) and the m1/m2 ambiguity (fix(gcp/computeengine): m1/m2 on-demand pricing is ambiguous in us-east4, asia-southeast1 and asia-northeast1 #720) are pre-existing, correctly left out.
• Platform consumers get this only after a pin bump, as the body says.

CI at this SHA: CI - Build & Test run 42620439809 and pre-commit run 42620439826 both completed successfully. claude-darling has also approved this head, so with mine it has two approvals. GitHub reports it BEHIND by one commit, so it needs update-branch and a merge-only delta before merging. Review only, not merging.

[cristim]

Merge-only delta request: head is now a707449 (a707449), a plain merge of main at 81a7090 (#714) into the approved head 0c0c918, with no force-push.

• The merge brought one main commit, which touches CHANGELOG.md, pkg/recfilter and the Azure managed-Redis service. None overlaps this PR's two files (providers/gcp/services/computeengine/pricing.go and pricing_test.go).
• The merge tree has no conflicts. The branch differs from main only in those two files (+138/-8), unchanged since 0c0c918.
• The computeengine tests pass on the merged tree. Full CI is running at the new head.
  @claude-darling @claude-nibblets please confirm a merge-only delta at a707449. cc-libs's review is still open.

[cristim]

APPROVED a707449 by claude-darling

Delta review of the merge-only update 0c0c918..a707449 (main merged in). I approved 0c0c918 in full earlier.

• Remerge-diff is empty: git show --remerge-diff of the merge shows no conflict resolution, so the merge tree is exactly what git merges automatically.
• Delta is only main's fix(recfilter): dedupe each term and payment variant against the full held quantity #714: CHANGELOG.md, pkg/recfilter (dedupe, dedupe_ec2, a variants test) and the managedredis held-reservation test. git diff 0c0c9189..a70744992c57cf15ebc05c3e0262c5b3f40d96ac -- providers/gcp is empty, so both files I reviewed (pricing.go, pricing_test.go) are byte-identical to the approved head.
• One semantic touchpoint checked: providers/gcp/services/computeengine/dedupe_test.go calls recfilter.NewDuplicateChecker(...).AdjustRecommendationsForExisting, which fix(recfilter): dedupe each term and payment variant against the full held quantity #714 changed. Scoped run on this exact head (-run 'Dedupe|FindFamilyRates|GetComputePricing|EnrichRecWithPricing' in providers/gcp/services/computeengine) passes.
• Full suite: CI on this head. At the time of review 11 checks were still running and 1 had succeeded; I did not see a failure.

No actionable findings.

[cristim]

APPROVED a707449 by claude-nibblets

Merge-only delta from my full review at 0c0c9189. a707449 is a two-parent merge of 0c0c9189 and main 81a7090 (#714, "dedupe each term and payment variant against the full held quantity"). 0 behind main.

• The remerge-diff is empty: git show --remerge-diff a707449 shows no conflicts and no hand edits.
• No overlap: main changed CHANGELOG.md, pkg/recfilter/dedupe.go, pkg/recfilter/dedupe_ec2.go, pkg/recfilter/dedupe_variants_test.go and providers/azure/services/managedredis/held_reservation_dedupe_test.go since the merge base. This PR changes only providers/gcp/services/computeengine/pricing.go and pricing_test.go. The two file sets are disjoint.
• The PR's own change is unchanged: pricing.go and pricing_test.go at a707449 are byte-identical blobs to 0c0c9189's, and the PR's diff against main (+138/-8, the same two files) is identical to what I reviewed. So everything I verified at 0c0c9189 (the GBy.h conversion, the fail-closed allowlist, and the five killed probes) holds as written.

CI at this SHA: pre-commit run 42631960196 completed successfully, and CI - Build & Test run 42631960328 was still running when I posted. It must be green before merge (GitHub reports BLOCKED until it finishes). Review only, not merging.

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• Repository: LeanerCloud/cloud-commitments-go
• Branch: fix/394-gcp-decimal-gb-ram
• File: .coderabbit.yaml
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Files selected for processing: 2

• providers/gcp/services/computeengine/pricing.go
• providers/gcp/services/computeengine/pricing_test.go

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