GCP billing — baseline, improvements, forecast

Financial snapshot for Oter (LifeCommanderKMP) and Negodex on Google Cloud. Ops details and rollback steps live in gcp-cost-cuts.md.

Scope

Project	ID	What runs there
Oter	`oter-490318`	Ktor API (`oter`), Next.js web (`oter-web`), Cloud SQL `oter-db`, Artifact Registry
Negodex	`negodex`	Nest API (`api`), admin/web frontends; no Cloud SQL after 2026-05-25 (uses Oter’s instance)

Billing may appear on one GCP billing account (combined invoice) or per project depending on how the account is linked. Use Billing → Reports → Group by: Project to split Oter vs Negodex when validating savings.

1. Previous billing (baseline)

Measurement period

Field	Value
Period	2026-04-07 → 2026-04-30 (~23 days)
Currency reported	COP (Colombian peso)
FX used below	~4,100 COP/USD (derived from line items; use your invoice for exact rates)

Line items (as reported)

SKU	COP (23 days)	~USD (23 days)	~USD / month (× 30/23)	Primary driver
Cloud SQL	144,875	~$35	~$46	Postgres always-on (`oter-db`; possibly includes shared-account SQL if Negodex billed here)
Cloud Logging	131,398	~$32	~$42	Ingestion + storage; server at DEBUG, 30-day retention, no exclusions
Cloud Run	32,044	~$8	~$10	Scale-to-zero services; Oter API at 2 vCPU / 1 GiB
Artifact Registry	258	~$0.06	~$0.08	Negligible
Total (these SKUs)	308,575	~$75	~$98

What drove each cost (before cuts)

Cloud SQL (~46 USD/mo projected)

Instance oter-db: tier db-custom-1-3840, Postgres 18, 10 GB disk, backups enabled.
Separate instance negodex-pg in project negodex (same tier) added ~$50–60/mo if billed on the same account or on Negodex’s project — not always visible in a single-project export.

Cloud Logging (~42 USD/mo projected)

Largest avoidable cost. Root causes:
- logback.xml defaulted to DEBUG; Flyway, Postgres driver, and Ktor also at DEBUG.
- Cloud Run deploy did not set LOG_LEVEL=INFO.
- _Default bucket: 30-day retention.
- No sink exclusions for health checks or DEBUG severity.

Cloud Run (~10 USD/mo projected)

Already efficient (scale to zero on web). Oter API oversized at 2 CPU / 1 GiB.
Windmill was never deployed on GCP (no spend; repo workflow would have cost ~$210/mo if deployed — see automation-options.md).

Artifact Registry

Storage only; no material cost.

Baseline scenarios

Scenario	Estimated total / month
A — April numbers = entire billing account (both apps, one SQL line item)	~$98
B — April = `oter-490318` only; Negodex SQL billed separately	~$98 (Oter) + ~$50–60 (Negodex SQL) ≈ $148–158

Confirm which scenario applies in Billing → Reports → Group by: Project for April.

2. Improvements applied (2026-05-25)

#	Change	Est. monthly savings	Risk	Status
1	Logging: `LOG_LEVEL=WARN`, logback WARN defaults, live `oter` updated	$25–35	Low	Done
2	Logging (GCP): retention 1d; exclusions (health, DEBUG, INFO/NOTICE, Cloud Run below ERROR) on `oter-490318` + `negodex`	→ ~$0 (free tier)	Low — less visibility	Done
3	Oter API: Cloud Run 1 vCPU / 512 MiB (was 2 / 1 GiB)	$2–4	Low — monitor cold starts	Done
4	Negodex SQL: `myecommercedb` on `oter-db`; deleted `negodex-pg`	$50–60	Medium — PG16→18 migration; smoke-test app	Done
5	Artifact Registry: cleanup policy (keep 5 tags; delete untagged >30d)	~$0 (prevents growth)	Low	Done
6	Windmill: repo removed; never on GCP	$0 today; ~$210 avoided if deployed	—	Done (repo)

Technical summary

Oter (oter-490318)

Logging and CPU/RAM: workflow + live revision oter-00033-jb2.
Redeploy via Publish Server Release after merge so the Docker image includes hardened logback.xml.
oter-db still db-custom-1-3840; backups already 7 retained / 7-day transaction logs.

Negodex (negodex)

DB host secret → /cloudsql/oter-490318:us-east1:oter-db.
api Cloud Run attached to shared instance; api-runtime@negodex granted roles/cloudsql.client on oter-490318.
negodex-pg instance deleted after successful restore and Nest startup.

Not changed yet (deferred)

Downgrade oter-db machine tier (wait 48h stable dual-app load).
Drop legacy database oter on oter-db if confirmed unused.

Full runbook: gcp-cost-cuts.md.

3. Expected billing (forecast)

Estimates are ranges until one full billing cycle (7–30 days) after 2026-05-25. Traffic and cross-project billing grouping affect actuals.

By SKU (monthly USD)

SKU	Before (scenario A)	Before (scenario B)	After (expected)	Notes
Cloud SQL	~$46	~$96–106	~$46–52	One instance (`oter-db`) for both apps; slight load increase vs Oter-only
Cloud Logging	~$42	~$42	~$0–3	WARN app logs + ingest exclusions; aim for under 50 GiB/mo free
Cloud Run	~$10	~$10–15	~$7–9	Oter API smaller; Negodex unchanged
Artifact Registry	~$0	~$0	~$0	Cleanup policy
Total	~$98	~$148–158	~$22–38 (A) or ~$57–67 (B)

Scenario A — April total was ~$98 (combined view)

	USD / month
Previous	~$98
Expected	~$22–38
Savings	~$60–76 (~61–78%)

Largest drivers: logging cut + removal of second SQL instance (if it was already inside the same $46 SQL line, savings show up as lower SQL growth or a second project dropping off — verify in console).

Scenario B — Negodex SQL was extra (~$50–60/mo)

	USD / month
Previous (Oter + Negodex)	~$148–158
Expected	~$63–73
Savings	~$75–95 (~50–60%)

COP reference (at ~4,100 COP/USD)

	COP / month (approx.)
Previous (scenario A)	~402,000
Expected (scenario A)	~115,000–185,000
Previous (scenario B)	~607,000–648,000
Expected (scenario B)	~258,000–299,000

4. How to verify actuals

Open GCP Billing → Reports.
Set range: first full month after 2026-05-25.
Group by: SKU — compare Cloud Logging, Cloud SQL, Cloud Run to tables above.
Group by: Project — confirm negodex has no Cloud SQL line item; SQL spend should sit under oter-490318.
Optional: export CSV and archive next to this doc (e.g. docs/infra/billing-exports/YYYY-MM.csv).

Success criteria

SKU	Target vs April baseline
Cloud Logging	>90% decrease (ideally $0 within free tier)
Cloud SQL	~50% decrease if two instances before; flat ~$46–52 if one shared instance already in baseline
Cloud Run	~10–30% decrease on Oter project

5. Near-zero Cloud Logging (2026-05-25 update)

GCP bills $0 for the first 50 GiB/month of log ingestion (then ~$0.50/GiB). To get close to $0:

Layer	What we did
Application	`LOG_LEVEL=WARN` — no routine INFO/DEBUG to stdout
Ingest exclusions	Do not store Cloud Run logs below ERROR; drop INFO/NOTICE/DEBUG and health probes
Retention	1 day on `_Default` (less storage cost if you ever exceed free tier)

Trade-off: Logs Explorer shows mostly errors for Cloud Run. For a short investigation:


gcloud run services update oter --region=us-east1 --project=oter-490318 --update-env-vars=LOG_LEVEL=INFO
# when done:
gcloud run services update oter --region=us-east1 --project=oter-490318 --update-env-vars=LOG_LEVEL=WARN

Negodex: same sink rules on project negodex; lower Nest logger level in the Negodex repo if INFO lines remain high.

6. Future levers (not in current forecast)

Lever	Potential savings	When
Downgrade `oter-db` tier after 48h stable	$0–15/mo	After Negodex + Oter verified
Drop unused DB `oter`	Disk/admin only	After backup + confirm unused
Negodex `web` `minScale=1` → 0 if acceptable	$1–3/mo	Product decision (cold start on web)
Deploy Windmill on Cloud Run worker pools	+$210/mo	Do not without automation-options.md

gcp-cost-cuts.md — applied changes, rollback, smoke tests
gcp-server-cloud-run.md — Oter API deploy
gcp-web-cloud-run.md — Oter web deploy
automation-options.md — automation cost comparison

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