第 4 部分:负载测试与自动扩缩容
难度:中级 预计时间:45 分钟 最后更新:February 22, 2026
学习目标
- 使用 k6 和 Locust 设计并执行负载测试场景
- 实时观察 KEDA 驱动的 Pod 自动扩缩容
- 在负载突增期间监控 Karpenter Node 自动扩缩容
- 构建用于可视化扩缩容事件的 Grafana 仪表板
前提条件
- [ ] 已完成第 3 部分:MSA 部署
- [ ] 正在运行已配置 OTel 插桩的 MSA 服务
- [ ] 已配置 KEDA 和 Karpenter
- [ ] 已在本地安装 k6(
brew install k6或apt install k6)
负载测试与扩缩容时间线
练习 1:k6 负载测试场景
步骤
步骤 1.1:创建 k6 负载测试脚本
bash
cat > ~/obs-lab/k6-load-test.js << 'EOF'
import http from 'k6/http';
import { check, sleep } from 'k6';
import { Rate, Trend } from 'k6/metrics';
// Custom metrics
const errorRate = new Rate('errors');
const orderLatency = new Trend('order_latency', true);
// Test configuration
export const options = {
stages: [
// Phase 1: Ramp-up
{ duration: '2m', target: 50 }, // Warm up
{ duration: '3m', target: 100 }, // Ramp to 100 VUs
// Phase 2: Sustained load
{ duration: '10m', target: 100 }, // Hold at 100 VUs
// Phase 3: Spike
{ duration: '2m', target: 300 }, // Spike to 300 VUs
{ duration: '3m', target: 500 }, // Peak at 500 VUs
{ duration: '2m', target: 500 }, // Hold peak
// Phase 4: Cool-down
{ duration: '3m', target: 100 }, // Ramp down
{ duration: '2m', target: 50 }, // Further down
{ duration: '3m', target: 0 }, // Complete cool-down
],
thresholds: {
http_req_duration: ['p(95)<500', 'p(99)<1000'],
errors: ['rate<0.1'],
order_latency: ['p(95)<800'],
},
};
const BASE_URL = __ENV.API_URL || 'http://api-gateway.msa.svc.cluster.local:8080';
// Test data
const products = ['PROD-001', 'PROD-002', 'PROD-003', 'PROD-004', 'PROD-005'];
const quantities = [1, 2, 3, 5, 10];
function randomItem(arr) {
return arr[Math.floor(Math.random() * arr.length)];
}
function generateOrder() {
return {
customer_id: `CUST-${Math.floor(Math.random() * 10000)}`,
product_id: randomItem(products),
quantity: randomItem(quantities),
payment_method: Math.random() > 0.5 ? 'credit_card' : 'debit_card',
};
}
export default function () {
// Scenario 1: Create Order (60% of traffic)
if (Math.random() < 0.6) {
const orderPayload = JSON.stringify(generateOrder());
const orderStart = Date.now();
const orderRes = http.post(`${BASE_URL}/api/v1/orders`, orderPayload, {
headers: {
'Content-Type': 'application/json',
'X-Request-ID': `req-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`,
},
tags: { name: 'CreateOrder' },
});
orderLatency.add(Date.now() - orderStart);
const orderSuccess = check(orderRes, {
'order created': (r) => r.status === 201,
'order has id': (r) => r.json('order_id') !== undefined,
});
errorRate.add(!orderSuccess);
}
// Scenario 2: Get Order Status (30% of traffic)
else if (Math.random() < 0.9) {
const orderId = `ORD-${Math.floor(Math.random() * 100000)}`;
const statusRes = http.get(`${BASE_URL}/api/v1/orders/${orderId}`, {
tags: { name: 'GetOrderStatus' },
});
const statusSuccess = check(statusRes, {
'status retrieved': (r) => r.status === 200 || r.status === 404,
});
errorRate.add(!statusSuccess);
}
// Scenario 3: List Orders (10% of traffic)
else {
const listRes = http.get(`${BASE_URL}/api/v1/orders?limit=10`, {
tags: { name: 'ListOrders' },
});
const listSuccess = check(listRes, {
'list retrieved': (r) => r.status === 200,
});
errorRate.add(!listSuccess);
}
// Think time
sleep(Math.random() * 2 + 0.5);
}
export function handleSummary(data) {
return {
'stdout': textSummary(data, { indent: ' ', enableColors: true }),
'/tmp/k6-summary.json': JSON.stringify(data),
};
}
EOF步骤 1.2:负载测试阶段说明
| 阶段 | 时长 | VU | 目的 |
|---|---|---|---|
| 预热 | 5 分钟 | 10 → 100 | 逐步预热,触发初始扩缩容 |
| 持续负载 | 10 分钟 | 100 | 稳态,观察稳定指标 |
| 突增 | 7 分钟 | 100 → 500 | 压力测试,触发快速扩缩容 |
| 冷却 | 8 分钟 | 500 → 0 | 观察缩容,清理资源 |
步骤 1.3:获取 API Gateway URL
bash
kubectl config use-context $(kubectl config get-contexts -o name | grep obs-service)
API_URL=$(kubectl -n msa get svc api-gateway \
-o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
echo "API Gateway URL: http://$API_URL:8080"步骤 1.4:运行 k6 负载测试
bash
# Run load test
k6 run --env API_URL=http://$API_URL:8080 ~/obs-lab/k6-load-test.js
# Or run with output to Prometheus
k6 run --env API_URL=http://$API_URL:8080 \
--out experimental-prometheus-rw \
~/obs-lab/k6-load-test.js练习 2:Locust 替代方案(基于 Python)
步骤
步骤 2.1:创建 Locust Deployment
bash
cat <<'EOF' | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
name: locust-script
namespace: msa
data:
locustfile.py: |
from locust import HttpUser, task, between
import random
import json
class OrderUser(HttpUser):
wait_time = between(0.5, 2)
products = ['PROD-001', 'PROD-002', 'PROD-003', 'PROD-004', 'PROD-005']
@task(6)
def create_order(self):
order = {
'customer_id': f'CUST-{random.randint(1, 10000)}',
'product_id': random.choice(self.products),
'quantity': random.choice([1, 2, 3, 5, 10]),
'payment_method': random.choice(['credit_card', 'debit_card']),
}
with self.client.post(
'/api/v1/orders',
json=order,
headers={'Content-Type': 'application/json'},
catch_response=True
) as response:
if response.status_code == 201:
response.success()
else:
response.failure(f'Status: {response.status_code}')
@task(3)
def get_order_status(self):
order_id = f'ORD-{random.randint(1, 100000)}'
self.client.get(f'/api/v1/orders/{order_id}')
@task(1)
def list_orders(self):
self.client.get('/api/v1/orders?limit=10')
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: locust-master
namespace: msa
spec:
replicas: 1
selector:
matchLabels:
app: locust
role: master
template:
metadata:
labels:
app: locust
role: master
spec:
containers:
- name: locust
image: locustio/locust:2.22.0
ports:
- containerPort: 8089
- containerPort: 5557
command:
- locust
- --master
- --host=http://api-gateway:8080
volumeMounts:
- name: locust-script
mountPath: /home/locust
resources:
requests:
cpu: 100m
memory: 256Mi
volumes:
- name: locust-script
configMap:
name: locust-script
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: locust-worker
namespace: msa
spec:
replicas: 4
selector:
matchLabels:
app: locust
role: worker
template:
metadata:
labels:
app: locust
role: worker
spec:
containers:
- name: locust
image: locustio/locust:2.22.0
command:
- locust
- --worker
- --master-host=locust-master
volumeMounts:
- name: locust-script
mountPath: /home/locust
resources:
requests:
cpu: 500m
memory: 512Mi
volumes:
- name: locust-script
configMap:
name: locust-script
---
apiVersion: v1
kind: Service
metadata:
name: locust-master
namespace: msa
spec:
selector:
app: locust
role: master
ports:
- name: web
port: 8089
targetPort: 8089
- name: master
port: 5557
targetPort: 5557
type: LoadBalancer
EOF步骤 2.2:访问 Locust Web UI
bash
LOCUST_URL=$(kubectl -n msa get svc locust-master \
-o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
echo "Locust UI: http://$LOCUST_URL:8089"练习 3:在负载期间观察自动扩缩容
步骤
步骤 3.1:打开多个用于监控的终端窗口
bash
# Terminal 1: Watch Pod scaling
watch -n 2 'kubectl get pods -n msa -l app=order-service -o wide'
# Terminal 2: Watch HPA status
watch -n 5 'kubectl get hpa -n msa'
# Terminal 3: Watch Node scaling (Karpenter)
watch -n 10 'kubectl get nodes -l workload-type=msa'
# Terminal 4: Watch Karpenter logs
kubectl logs -n karpenter -l app.kubernetes.io/name=karpenter -f步骤 3.2:负载测试期间的观察要点
| 指标 | 观察位置 | 预期行为 |
|---|---|---|
| Pod 数量 | kubectl get pods -n msa | 2 → 8 → 30 → 2 |
| HPA 指标 | kubectl get hpa -n msa | CPU/请求速率增加 |
| Node 数量 | kubectl get nodes | 配置新的 Node |
| SQS 队列深度 | AWS Console / CloudWatch | 峰值期间突增 |
| Prometheus 指标 | Grafana Explore | 请求速率、延迟 |
| Trace | Tempo / Grafana | 端到端延迟 |
步骤 3.3:KEDA 扩缩容事件
bash
# Watch KEDA events
kubectl get events -n msa --field-selector reason=KEDAScaleTargetActivated -w
# Check ScaledObject status
kubectl describe scaledobject -n msa order-service-scaler步骤 3.4:Karpenter 配置事件
bash
# Watch node provisioning
kubectl get events -A --field-selector reason=Provisioned -w
# Check NodePool status
kubectl describe nodepool msa-workloads练习 4:冷却与缩容观察
步骤
步骤 4.1:在负载测试完成后监控缩容
bash
# Watch Pod termination
kubectl get pods -n msa -l app=order-service -w
# Watch node consolidation
kubectl get events -A --field-selector reason=Consolidated -w步骤 4.2:缩容时间线
| 负载结束后的时间 | Pod 数量 | Node 数量 | 说明 |
|---|---|---|---|
| 0 分钟 | 30 | 8+ | 峰值状态 |
| 2 分钟 | 20 | 8+ | HPA 冷却开始 |
| 5 分钟 | 10 | 6 | Pod 正在终止 |
| 10 分钟 | 4 | 4 | Karpenter 正在整合 |
| 15 分钟 | 2 | 3 | 接近基准状态 |
| 20 分钟 | 2 | 2 | 已恢复基准状态 |
步骤 4.3:验证成本优化
bash
# Check spot instance usage
kubectl get nodes -o custom-columns=NAME:.metadata.name,TYPE:.metadata.labels.karpenter\\.sh/capacity-type,INSTANCE:.metadata.labels.node\\.kubernetes\\.io/instance-type
# Expected: Mix of spot and on-demand instances练习 5:Grafana 扩缩容仪表板
步骤
步骤 5.1:创建扩缩容仪表板面板
| 面板 | 指标查询 | 可视化 |
|---|---|---|
| Pod 数量 | sum(kube_deployment_status_replicas{namespace="msa"}) by (deployment) | 时间序列 |
| Node 数量 | count(kube_node_info{node=~".*msa.*"}) | 统计 |
| CPU 使用率 | sum(rate(container_cpu_usage_seconds_total{namespace="msa"}[5m])) by (pod) | 时间序列 |
| 内存使用率 | sum(container_memory_working_set_bytes{namespace="msa"}) by (pod) | 时间序列 |
| SQS 队列深度 | aws_sqs_approximate_number_of_messages_visible_average{queue_name="obs-lab-orders"} | 时间序列 |
| 请求速率 | sum(rate(http_server_request_count{namespace="msa"}[1m])) by (service) | 时间序列 |
| 错误率 | sum(rate(http_server_request_count{namespace="msa",http_status_code=~"5.."}[1m])) / sum(rate(http_server_request_count{namespace="msa"}[1m])) | 仪表盘 |
| P99 延迟 | histogram_quantile(0.99, sum(rate(http_server_request_duration_seconds_bucket{namespace="msa"}[5m])) by (le, service)) | 时间序列 |
步骤 5.2:导入仪表板 JSON
bash
cat > /tmp/scaling-dashboard.json << 'EOF'
{
"dashboard": {
"title": "MSA Scaling Dashboard",
"tags": ["obs-lab", "scaling", "k6"],
"timezone": "browser",
"panels": [
{
"title": "Pod Replicas by Deployment",
"type": "timeseries",
"gridPos": {"h": 8, "w": 12, "x": 0, "y": 0},
"targets": [{
"expr": "sum(kube_deployment_status_replicas{namespace=\"msa\"}) by (deployment)",
"legendFormat": "{{deployment}}"
}]
},
{
"title": "Node Count",
"type": "stat",
"gridPos": {"h": 4, "w": 6, "x": 12, "y": 0},
"targets": [{
"expr": "count(kube_node_info)"
}]
},
{
"title": "Request Rate",
"type": "timeseries",
"gridPos": {"h": 8, "w": 12, "x": 0, "y": 8},
"targets": [{
"expr": "sum(rate(http_server_request_count{namespace=\"msa\"}[1m])) by (service)",
"legendFormat": "{{service}}"
}]
},
{
"title": "P99 Latency (ms)",
"type": "timeseries",
"gridPos": {"h": 8, "w": 12, "x": 12, "y": 8},
"targets": [{
"expr": "histogram_quantile(0.99, sum(rate(http_server_request_duration_seconds_bucket{namespace=\"msa\"}[5m])) by (le, service)) * 1000",
"legendFormat": "{{service}}"
}]
}
]
}
}
EOF
# Import via Grafana API
curl -X POST -H "Content-Type: application/json" \
-u admin:ObsLab2026! \
-d @/tmp/scaling-dashboard.json \
"http://$GRAFANA_URL/api/dashboards/db"步骤 5.3:为扩缩容事件创建注释
bash
# Add Prometheus recording rules for scaling events
cat <<'EOF' | kubectl apply -f -
apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
name: scaling-events
namespace: monitoring
spec:
groups:
- name: scaling-events
rules:
- record: scaling:pod_scale_up
expr: |
changes(kube_deployment_status_replicas{namespace="msa"}[5m]) > 0
and
delta(kube_deployment_status_replicas{namespace="msa"}[5m]) > 0
- record: scaling:pod_scale_down
expr: |
changes(kube_deployment_status_replicas{namespace="msa"}[5m]) > 0
and
delta(kube_deployment_status_replicas{namespace="msa"}[5m]) < 0
- record: scaling:node_added
expr: |
changes(kube_node_created{node=~".*msa.*"}[10m]) > 0
EOF验证
bash
# Open Grafana dashboard
echo "Grafana URL: http://$GRAFANA_URL"
echo "Dashboard: MSA Scaling Dashboard"
# Verify metrics are populated
curl -s -u admin:ObsLab2026! \
"http://$GRAFANA_URL/api/datasources/proxy/1/api/v1/query?query=kube_deployment_status_replicas" | jq总结
在本实验中,你已完成:
| 任务 | 状态 |
|---|---|
| k6 负载测试脚本 | 已创建 |
| Locust Deployment | 已部署 |
| Pod 自动扩缩容(KEDA) | 已观察 |
| Node 自动扩缩容(Karpenter) | 已观察 |
| 缩容行为 | 已验证 |
| 扩缩容仪表板 | 已创建 |
关键观察结果
| 指标 | 基准 | 峰值 | 恢复后 |
|---|---|---|---|
| Order Service Pod | 2 | 30 | 2 |
| Node 总数 | 3 | 8+ | 3 |
| 请求速率 | 0 | 500+ RPS | 0 |
| P99 延迟 | <100ms | <500ms | <100ms |
| 错误率 | 0% | <1% | 0% |
清理
清理工作将在第 6 部分中执行。
故障排除
k6 无法访问 API Gateway
- 验证 LoadBalancer 是否具有外部 IP:
kubectl get svc -n msa api-gateway - 检查安全组是否允许入站流量
- 测试连通性:
curl http://$API_URL:8080/health
Pod 未扩缩容
- 检查 HPA 状态:
kubectl describe hpa -n msa - 验证 KEDA ScaledObject:
kubectl describe scaledobject -n msa - 检查指标是否可用:
kubectl top pods -n msa
Node 未配置
- 检查 Karpenter 日志:
kubectl logs -n karpenter -l app.kubernetes.io/name=karpenter - 验证 NodePool 限制:
kubectl describe nodepool msa-workloads - 检查 AWS 账户中的 EC2 实例限制
后续步骤
继续学习第 5 部分:告警与 AIOps,以配置告警和 AI 驱动的事件响应。