> ## Documentation Index
> Fetch the complete documentation index at: https://proxy-hopper.io/llms.txt
> Use this file to discover all available pages before exploring further.

# High Availability

> Run Proxy Hopper at scale with HPA, Redis, and production hardening.

## Overview

Proxy Hopper is stateless beyond its IP pool state. With Redis as the backend, multiple replicas share a single pool — each IP is checked out to exactly one replica at a time via Redis `BLPOP` atomicity. This makes horizontal scaling straightforward.

## HorizontalPodAutoscaler

```yaml theme={}
autoscaling:
  enabled: true
  minReplicas: 2
  maxReplicas: 10
  targetCPUUtilizationPercentage: 80
```

<Note>
  HPA with multiple replicas **requires the Redis backend**. The in-memory backend gives each pod its own independent pool state — IPs may be used concurrently across pods and quarantine state is not shared.
</Note>

## Redis for HA

Use a managed Redis service for production rather than the bundled Bitnami subchart:

```yaml theme={}
backend:
  type: redis
  redis:
    url: redis://my-managed-redis:6379/0

redis:
  enabled: false   # disable bundled subchart
```

Managed Redis options:

* **AWS** — ElastiCache for Redis
* **GCP** — Cloud Memorystore
* **Azure** — Azure Cache for Redis
* **Self-hosted** — Redis Sentinel or Redis Cluster with persistence enabled

## PodDisruptionBudget

Maintain minimum availability during node drain and rolling upgrades:

```yaml theme={}
apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: proxy-hopper
  namespace: proxy-hopper
spec:
  minAvailable: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: proxy-hopper
```

The Helm chart does not create a PDB automatically — apply this separately.

## Resource requests and limits

Proxy Hopper is I/O-bound. CPU usage is low; memory scales with the number of open connections.

```yaml theme={}
resources:
  requests:
    cpu: 100m
    memory: 128Mi
  limits:
    cpu: 500m
    memory: 256Mi
```

Start conservative and adjust based on observed usage (`kubectl top pods`).

## Health probes

Proxy Hopper exposes readiness and liveness endpoints. The Helm chart configures these automatically, but if you are deploying manually:

```yaml theme={}
livenessProbe:
  httpGet:
    path: /health
    port: admin   # admin API port (default 8081)
  initialDelaySeconds: 5
  periodSeconds: 10

readinessProbe:
  httpGet:
    path: /health
    port: admin
  initialDelaySeconds: 3
  periodSeconds: 5
```

The admin API must be enabled for health endpoints to be available:

```yaml theme={}
admin:
  enabled: true
  port: 8081
```

## Example: full HA values file

```yaml theme={}
replicaCount: 2

autoscaling:
  enabled: true
  minReplicas: 2
  maxReplicas: 10
  targetCPUUtilizationPercentage: 80

backend:
  type: redis
  redis:
    url: redis://my-managed-redis:6379/0

redis:
  enabled: false

resources:
  requests:
    cpu: 100m
    memory: 128Mi
  limits:
    cpu: 500m
    memory: 256Mi

admin:
  enabled: true
  port: 8081

config:
  existingSecret: proxy-hopper-config

ingress:
  enabled: true
  className: nginx
  hosts:
    - host: proxy-hopper.example.com
      paths:
        - path: /
          pathType: Prefix
```

## Production checklist

<AccordionGroup>
  <Accordion title="Use a Secret for config with auth">
    If auth is enabled, store the config in a Kubernetes Secret and reference it with `config.existingSecret`. Credentials in `config.inline` end up in Helm release history.
  </Accordion>

  <Accordion title="Use managed Redis">
    The bundled Redis subchart is convenient for development but not hardened for production. Use a managed service with persistence and replication enabled.
  </Accordion>

  <Accordion title="Set resource requests and limits">
    Without resource limits, a traffic spike can starve other pods on the node. Set limits based on observed memory usage under load.
  </Accordion>

  <Accordion title="Add a PodDisruptionBudget">
    Ensure at least one replica remains available during node maintenance or rolling upgrades.
  </Accordion>

  <Accordion title="Enable the admin API for health checks">
    The `/health` endpoint on the admin port is the most reliable liveness/readiness signal. Enable `admin.enabled: true` in your values.
  </Accordion>
</AccordionGroup>