用Jmeter - Kubernetes测试后，spring boot的容器内存使用率不低

Question

早上好我有一个问题，我对Kubernetes和Java（spring-boot）比较陌生，目前我正在部署一个带有三个容器的pod，带有spring-boot，问题是我正在用Jmeter测试，以测量度量并使用Kubernete中的HPA自动伸缩，但当你强调容器的内存增加时，我会得到这个结果，但当我完成测试时，容器不会降低内存使用。我不知道这个主题是否是Java的典型主题，因为JVM，或者垃圾收集器是否出现故障，我必须在docker映像中定义它。我在yaml清单中给了他一个关于容器中CPU和内存的资源限制

这是我的容器在用Jmeter开始测试之前的情况

用Jmeter测试后，又通行了大约15分钟，容器在记忆方面也是如此:

这就是我定义Dockerfile的方式：

FROM openjdk:8-alpine
RUN rm -rf /var/cache/apk/*
RUN rm -rf /tmp/*
RUN apk update
RUN apk add busybox-extras
ENV UBICATION_CERTIFICATE_SSL=/etc/letsencrypt/tmp224.p12
ENV PASSWORD_CERTIFICATE_SSL=xxxxx
ENV ALIAS_CERTIFICATE_SSL=tmp224
ADD FindAccountNumber-0.0.1-SNAPSHOT.jar /home/app.jar
ADD tmp224.p12 /etc/letsencrypt/tmp224.p12
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/home/app.jar"]

还有我的货单yaml：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: find-complementary-account-info-1
  labels:
    app: find-complementary-account-info-1
spec:
  replicas: 2
  selector:
    matchLabels:
      app: find-complementary-account-info-1
  template:
    metadata:
      labels:
        app: find-complementary-account-info-1
    spec:
      containers:
      - name: find-account-number-1
        image: find-account-number:latest
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            cpu: "250m"
            memory: "350Mi"
          requests:
            cpu: "150m"
            memory: "300Mi"
        ports:
        - containerPort: 8081
        env:
        - name: URL_CONNECTION_BD
          value: jdbc:oracle:thin:@xxxxxxxx:1531/DEFAULTSRV.WORLD
        - name: USERNAME_CONNECTION_BD
          valueFrom:
            secretKeyRef:
              name: credentials-bd-pers
              key: user_pers
        - name: PASSWORD_CONNECTION_BD
          valueFrom:
            secretKeyRef:
              name: credentials-bd-pers
              key: password_pers
      - name: find-account-validators-1
        image: find-account-validators:latest
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            cpu: "250m"
            memory: "350Mi"
          requests:
            cpu: "150m"
            memory: "300Mi"
        ports:
        - containerPort: 8082
        env:
        - name: URL_CONNECTION_BD
          value: jdbc:oracle:thin:@xxxxxxxx:1522/DEFAULTSRV.WORLD
        - name: USERNAME_CONNECTION_BD
          valueFrom:
            secretKeyRef:
              name: credentials-bd-billing
              key: user_billing
        - name: PASSWORD_CONNECTION_BD
          valueFrom:
            secretKeyRef:
              name: credentials-bd-billing
              key: password_billing
      - name: find-complementary-account-info-1
        image: find-complementary-account-info:latest
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            cpu: "250m"
            memory: "350Mi"
          requests:
            cpu: "150m"
            memory: "300Mi"
        ports:
        - containerPort: 8083
        env:
        - name: UBICATION_URL_ACCOUNT_NUMBER
          value: "https://localhost:8081/api/FindAccountNumber"
        - name: UBICATION_URL_ACCOUNT_VALIDATORS
          value: "https://localhost:8082/api/FindAccountValidator"
---

apiVersion: v1
kind: Service
metadata:
  name: svc-find-complementary-account-info-1
  labels:
    app: find-complementary-account-info-1
  annotations:
    metallb.universe.tf/allow-shared-ip: shared-ip
  namespace: default
spec:
  selector:
    app: find-complementary-account-info-1
  externalTrafficPolicy: Cluster
  loadBalancerIP: 10.161.174.68
  type: LoadBalancer
  ports:
   -
    protocol: TCP
    port: 8083
    targetPort: 8083
    nodePort: 30025
---

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: find-complementary-account-info-1
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: find-complementary-account-info-1
  minReplicas: 2
  maxReplicas: 5
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 70

如何减少容器中使用Spring引导时的内存，因为我认为它会随着压力的增加而不断增加

Answer 1

我认为差异很小（〜220 MB与250-290 MB），你不应该为此烦恼。

但是你好像在说java应用程序(不是)把内存还给操作系统。很长一段时间以来，这一直是一种常见的行为，它依赖于垃圾收集器——这并不意味着垃圾收集器不起作用。你正在使用JDK 8，所以你没有太多的选择，但在以后的版本中有改进的收集器，例如

< Li > JDK 12的G1 GC:及时从G1返回未使用的提交内存 雪兰多

您可以在此处找到更多信息：GC是否将内存释放回操作系统？