ADR-0006: Managed Redis for the original hosted deployment

Status

superseded for self-hosting

Decided

September 2026 (hosted deployment, ADR-0004)

Applies to this repository

Partly: core needs a Redis-API server; which one is your choice.

Context

Core uses one Spring Data Redis connection (spring.data.redis.host/port/password, i.e. REDIS_HOST, REDIS_PORT, REDIS_PASSWORD) for rate limiters, session memory, response caches and similar consumers. The hosted deployment used its cloud's managed Redis, reached over a private network, instead of a Redis container.

Decision (historical)

Use the cloud's managed Redis: plaintext protocol inside the private network, single node, no clustering. Core's Redis configuration has no TLS setup, which is why plaintext on a private network was accepted.

What applies to self-hosters

• Compose and Helm bundle Valkey (Redis API, valkey/valkey:8.1-alpine), single node, password from VALKEY_PASSWORD or the chart Secret.
• To use your own Redis-compatible service, set the Helm global.valkey host values (or REDIS_* for core) and disable the bundled one. Keep it on a private network: core does not configure TLS to Redis.
• Redis contents are disposable by design (caches, sessions, rate-limit windows); back up Postgres, not Redis.

Evidence & references

• core/app-config/src/main/resources/application.yml — spring.data.redis block.
• deploy/compose/docker-compose.yml (valkey), deploy/helm/charts/valkey, deploy/helm/charts/vegaduta/values.yaml (global.valkey).