Cache

Configure Porch caching mechanisms

Porch supports two caching mechanisms to store package metadata and improve performance.

Cache Types

CR Cache (Default)

By default, Porch uses Custom Resource (CR) cache, which stores cache data as Kubernetes Custom Resources.

Advantages:

No additional infrastructure required
Automatic backup with cluster backups
Simple setup and maintenance

Use when:

Getting started with Porch
Small to medium deployments
Simplicity is preferred

Database Cache

Database cache uses PostgreSQL to store cache data, providing better performance for large deployments.

Advantages:

Better performance with large datasets
Advanced querying capabilities
Separate scaling from Kubernetes cluster

Use when:

Large-scale deployments
High-performance requirements
Advanced querying needs

Switching to Database Cache

Prerequisites

PostgreSQL database (v12+) running and accessible
Database credentials and connection details
Database must have the specified database created (e.g., porch)

Important

Ensure your PostgreSQL instance is running and accessible from the Porch server before configuring database cache. Porch will fail to start if it cannot connect to the database.

Configuration Steps

Create Database Secret:

kubectl create secret generic porch-db-config \
  --namespace=porch-system \
  --from-literal=host=postgresql.example.com \
  --from-literal=port=5432 \
  --from-literal=database=porch \
  --from-literal=username=porch_user \
  --from-literal=password=your_password

Configure Database Cache:

For Catalog Deployments (Pre-deployment):

Modify the package configuration before deployment:

# Get the catalog package
kpt pkg get https://github.com/nephio-project/catalog/tree/main/nephio/core/porch
cd porch/
# Edit the porch-server deployment YAML in the package

For Manual Deployments (Post-deployment):

Update an existing deployment:

kubectl edit deployment -n porch-system porch-server

Configuration (both methods):

Add database configuration to the porch-server deployment:

spec:
  template:
    spec:
      containers:
      - name: porch-server
        args:
        - --cache-type=DB
        env:
        - name: DB_DRIVER
          value: "pgx"
        - name: DB_HOST
          valueFrom:
            secretKeyRef:
              name: porch-db-config
              key: host
        - name: DB_PORT
          valueFrom:
            secretKeyRef:
              name: porch-db-config
              key: port
        - name: DB_NAME
          valueFrom:
            secretKeyRef:
              name: porch-db-config
              key: database
        - name: DB_USER
          valueFrom:
            secretKeyRef:
              name: porch-db-config
              key: username
        - name: DB_PASSWORD
          valueFrom:
            secretKeyRef:
              name: porch-db-config
              key: password

Restart Porch Server:

kubectl rollout restart deployment/porch-server -n porch-system

Local Development with Database Cache

For local development with database cache, see the Local Development Environment guide which covers both CR cache and database cache options.

Monitoring Cache Performance

Metrics

Porch exposes cache-related metrics:

# Check cache hit rates
kubectl port-forward -n porch-system svc/porch-server 8080:8080
curl http://localhost:8080/metrics | grep cache

Logs

Monitor cache operations:

kubectl logs -n porch-system -l app=porch-server -f | grep cache

Troubleshooting

Common Issues

Database connection failures:

# Check secret configuration
kubectl get secret porch-db-config -n porch-system -o yaml

# Verify database connectivity
kubectl run -it --rm debug --image=postgres:12 --restart=Never -- \
  psql -h postgresql.example.com -U porch_user -d porch

Performance issues:

Monitor database performance
Check network latency between Porch and database
Review database indexes and query performance