---
title: Redis
url: "/docs/caches/redis/"
canonical_url: https://docs.blossom88.com/docs/caches/redis/
markdown_url: https://docs.blossom88.com/docs/caches/redis.md
summary: Persistent Redis caches with backups, replication, monitoring, and failover
categories:
- data
- caches
- redis
---

# Redis

Blossom runs Redis 8 as a Cache with a stable private endpoint, generated
authentication, append-only persistence, and engine-specific monitoring.

## Persistence And Recovery

Append-only persistence protects data during ordinary Redis process recovery.
Selected Backup Storage adds daily encrypted RDB backups. A completed backup
can restore an independent Cache or rebuild the primary after local data is
lost.

Local persistence and recovery backups protect different failures. A
single-node Cache is recovery-protected, not highly available. Restoring the
latest backup takes time, and writes newer than the
latest completed backup can be lost.

See [Redis Recovery Backups](/docs/backups/managed-cache/).

## Read Replicas

Redis supports up to five direct read replicas. Each replica runs independently,
follows the primary, rejects writes, and exposes a stable private
endpoint. Applications connect directly to a replica endpoint when they want
to scale read traffic.

## Dedicated Standby

Set `standby: true` on a Dedicated Redis Cache, or check **Standby with
automatic failover** on the Cache, and one dedicated standby continuously
follows the primary. It is reserved for
recovery and does not serve application traffic. Keeping that role separate
from read replicas provides one known promotion target whose capacity is not
consumed by application reads.

A planned switchover pauses writes, confirms the standby has acknowledged the
primary's final replication offset, fences the old primary, promotes the
standby, and moves the stable Cache endpoint. Automatic failover uses the same
promotion path only after Blossom proves the old primary cannot accept writes.

    blossom cache_instance:switchover --id cache_instance-100 --yes --follow

Redis replication is asynchronous. Blossom protects data confirmed on the
standby before failure; it does not claim that an unreplicated final write will
survive sudden primary loss.

## Monitoring

The Monitoring view compares Cache Nodes and shows connections, commands,
memory, keyspace activity, persistence health, container CPU and memory, and a
separate replication-lag line for every replica and standby. Select a node to
inspect its role and resource pressure directly.

## Connect

Create an Environment Link with `target_type: CacheInstance`. Blossom supplies a
private, authenticated `REDIS_URL` to every Service in that Environment.

- [Caches](/docs/caches/)
- [Database And Cache Security](/docs/databases/security/)
- [Redis documentation](https://redis.io/docs/latest/)