<!-- m-wiki: type=concept slug=node-pool-selection topic=infra base-sha=28f54cf7bef9 generated-at=2026-05-12T00:00:00+00:00 sources=[] -->

> Generated 2026-05-12 at base-sha 28f54cf7bef9. Type: concept. 0 sources.

# GKE Node Pool Selection

`nodePoolSelection.run(memory_request, cpu_request, priority_v2)` computes the GKE node pool label for the deployed application (not the Jenkins build agent). The label is written to the Helm values as `nodeSelectorValue`.

## Where it applies in this repo

`src/com/meesho/utilities/nodePoolSelection.groovy:run`

**Selection logic (prd only):**

1. Parse `memory_request` (Mi or Gi) and `cpu_request` (m or whole cores) to numeric values.
2. Compute `ratio = memory_mb / cpu_millicores`.
3. For **non-critical priorities** (cp1-cp3, up1-up3, sp1-sp3): node name is `{mega|sumo}{tetra|duo}lite`.
   - `cpu_req >= 2200m` → `sumo`; else `mega`.
   - `ratio >= 2.5` → `tetra`; else `duo`.
4. For **critical priorities** (sp0, up0, cp0 — not explicitly listed but implied): node name is `{compact|mega|sumo}{duo|tetra|octa}`.
   - `cpu_req >= 2200m` → `sumo`; `1000m-2199m` → `mega`; `<1000m` → `compact`.
   - `ratio > 5.5` → `octa`; `>= 2.5` → `tetra`; else `duo`.
5. BU-specific overrides for `supply` and `demand` apply to certain `{nodevalue, ratiovalue}` combinations.

**Non-prd environments:**
- `int` → `preprod-cost-optimized`
- `stg`/`ftr`/`dev` → `{BU}-shared`

The result is set as `value_binding1['nodeSelectorValue']` in `deployArgoCD.update_helm_repo`.

## Why this design

GKE node pools are heterogeneous — some are memory-optimized, some CPU-optimized. Placing services on the wrong pool wastes resources or causes throttling. The automated selection reduces per-team cognitive load: teams declare their resource needs in `deployment.yaml` and the pipeline finds the best matching pool.

The BU-specific overrides exist because certain BUs have limited availability of some pool types in the region — the fallback to `tetra` avoids scheduling failures on unavailable pools.

## Related

- [Deploy ArgoCD](../04-DEPLOY-ARGOCD.md) — nodeSelectorValue is computed in update_helm_repo
- [Infra pods](../09-INFRA-PODS.md) — build agent pod selection (separate from app node pool)

## Sources

(no raw/ sources at bootstrap)

## Notes

<!-- Anything below is human-owned. wiki-init never reads or modifies content under this heading. -->

---

[← Wiki index](../../index.md)

<!-- atomic: keep this page ≤600 words. New scope → new concept page that builds on this one. Do not append paragraphs here. -->