WuKongIM supports dynamic scaling in Kubernetes environments, allowing flexible adjustment of cluster size based on business requirements.
Description
Applicable scenarios: Applications with high data security requirements, large applications.
Advantages: High availability, strong disaster recovery, supports online scaling, real-time automatic backup between multiple replicas, load balancing, no manual configuration required, fast scaling.
Note: WuKongIM currently supports hot scaling but does not support hot shrinking! Does not support hot shrinking! Does not support hot shrinking!
Scaling Operations
Scale Up Cluster
# Scale to 3 replicas
helm upgrade wkim wukongim/wukongim \
-n wukongim \
--create-namespace \
--version 0.1.0 \
--set replicaCount=3
replicaCount=3: Number of replicas (default is 2)externalIP=<IP_ADDRESS>: External IP address
Scale to Different Sizes
# Scale to 5 replicas for high load
helm upgrade wkim wukongim/wukongim \
-n wukongim \
--version 0.1.0 \
--set replicaCount=5
# Scale to 7 replicas for very high load
helm upgrade wkim wukongim/wukongim \
-n wukongim \
--version 0.1.0 \
--set replicaCount=7
Verify Scaling
# Check Pod status
kubectl get pods -n wukongim
# Check cluster nodes
kubectl port-forward svc/wkim-wukongim 5001:5001 -n wukongim &
curl http://localhost:5001/cluster/nodes
# View detailed cluster information
curl http://localhost:5001/cluster/nodes | jq '.'
Scaling Best Practices
Pre-Scaling Checklist
- Resource Planning: Ensure Kubernetes cluster has sufficient resources
- Monitoring: Check current resource usage and performance metrics
- Backup: Create backup before scaling operations
- Load Testing: Verify current performance baseline
Recommended Scaling Patterns
For Growing Load:
# Start with 3 replicas (minimum for HA)
helm upgrade wkim wukongim/wukongim -n wukongim --set replicaCount=3
# Scale to 5 for moderate load increase
helm upgrade wkim wukongim/wukongim -n wukongim --set replicaCount=5
# Scale to 7 for high load
helm upgrade wkim wukongim/wukongim -n wukongim --set replicaCount=7
# Scale with resource adjustments
helm upgrade wkim wukongim/wukongim \
-n wukongim \
--set replicaCount=5 \
--set resources.requests.memory=4Gi \
--set resources.requests.cpu=2000m \
--set resources.limits.memory=8Gi \
--set resources.limits.cpu=4000m
Post-Scaling Verification
# Check all pods are running
kubectl get pods -n wukongim -o wide
# Verify cluster health
kubectl exec -n wukongim deployment/wkim-wukongim -- \
curl -f http://localhost:5001/health
# Check cluster status
kubectl port-forward svc/wkim-wukongim 5001:5001 -n wukongim &
curl http://localhost:5001/cluster/nodes
# Monitor resource usage
kubectl top pods -n wukongim
kubectl top nodes
Monitoring During Scaling
Watch Scaling Progress
# Watch pods being created
kubectl get pods -n wukongim -w
# Monitor events
kubectl get events -n wukongim --sort-by='.lastTimestamp'
# Check deployment status
kubectl rollout status deployment/wkim-wukongim -n wukongim
# Check resource usage
kubectl top pods -n wukongim
# View logs during scaling
kubectl logs -f deployment/wkim-wukongim -n wukongim
# Monitor cluster metrics
kubectl port-forward svc/wkim-wukongim 5300:5300 -n wukongim &
curl http://localhost:5300/metrics
Troubleshooting Scaling Issues
Common Scaling Problems
Insufficient Resources:
# Check node resources
kubectl describe nodes
# Check resource requests vs limits
kubectl describe deployment wkim-wukongim -n wukongim
# View pod events
kubectl describe pods -n wukongim
# Check pod status
kubectl get pods -n wukongim
# View pod logs
kubectl logs <pod-name> -n wukongim
# Check pod events
kubectl describe pod <pod-name> -n wukongim
# Test inter-pod communication
kubectl exec -it <pod-name> -n wukongim -- ping <other-pod-ip>
# Check cluster ports
kubectl exec -it <pod-name> -n wukongim -- netstat -tulpn | grep 11110
# View cluster logs
kubectl logs <pod-name> -n wukongim | grep cluster
Recovery Procedures
# Rollback to previous replica count if issues occur
helm rollback wkim -n wukongim
# Force restart problematic pods
kubectl delete pod <pod-name> -n wukongim
# Check and fix resource constraints
kubectl patch deployment wkim-wukongim -n wukongim -p '{"spec":{"template":{"spec":{"containers":[{"name":"wukongim","resources":{"requests":{"memory":"4Gi","cpu":"2000m"}}}]}}}}'
Automated Scaling
Horizontal Pod Autoscaler (HPA)
# hpa.yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
name: wkim-hpa
namespace: wukongim
spec:
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
name: wkim-wukongim
minReplicas: 3
maxReplicas: 10
metrics:
- type: Resource
resource:
name: cpu
target:
type: Utilization
averageUtilization: 70
- type: Resource
resource:
name: memory
target:
type: Utilization
averageUtilization: 80
kubectl apply -f hpa.yaml
kubectl get hpa -n wukongim
Vertical Pod Autoscaler (VPA)
# vpa.yaml
apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
name: wkim-vpa
namespace: wukongim
spec:
targetRef:
apiVersion: apps/v1
kind: Deployment
name: wkim-wukongim
updatePolicy:
updateMode: "Auto"
resourcePolicy:
containerPolicies:
- containerName: wukongim
maxAllowed:
cpu: 4
memory: 8Gi
minAllowed:
cpu: 500m
memory: 1Gi
Optimal Replica Counts
| Load Level | Recommended Replicas | Use Case |
|---|
| Light | 3 | Development, small teams |
| Medium | 5 | Growing applications |
| High | 7 | Large applications |
| Very High | 9+ | Enterprise scale |
Resource Planning
# Calculate total resources needed
# For 5 replicas with 4Gi memory each = 20Gi total memory required
# For 5 replicas with 2 CPU each = 10 CPU cores total required
helm upgrade wkim wukongim/wukongim \
-n wukongim \
--set replicaCount=5 \
--set resources.requests.memory=4Gi \
--set resources.requests.cpu=2000m
Next Steps
