求基于Ubuntu20.04的Kubernetes部署Cassandra、Elasticsearch、JanusGraph的方案

一、部署Cassandra #

1. StatefulSet与Service YAML #

apiVersion: v1
kind: Service
metadata:
  name: cassandra
  labels:
    app: cassandra
spec:
  clusterIP: None
  ports:
    - port: 9042
  selector:
    app: cassandra
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: cassandra
spec:
  serviceName: cassandra
  replicas: 3
  selector:
    matchLabels:
      app: cassandra
  template:
    metadata:
      labels:
        app: cassandra
    spec:
      containers:
      - name: cassandra
        image: cassandra:4.1.3
        ports:
        - containerPort: 7000
          name: intra-node
        - containerPort: 7001
          name: tls-intra-node
        - containerPort: 7199
          name: jmx
        - containerPort: 9042
          name: cql
        resources:
          limits:
            cpu: "1000m"
            memory: 2Gi
          requests:
            cpu: "500m"
            memory: 1Gi
        volumeMounts:
        - name: cassandra-data
          mountPath: /var/lib/cassandra
        env:
          - name: CASSANDRA_SEEDS
            value: "cassandra-0.cassandra.default.svc.cluster.local"
          - name: CASSANDRA_CLUSTER_NAME
            value: "K8sCassandraCluster"
          - name: CASSANDRA_DC
            value: "DC1"
          - name: CASSANDRA_RACK
            value: "Rack1"
          - name: MAX_HEAP_SIZE
            value: 1G
          - name: HEAP_NEWSIZE
            value: 200M
  volumeClaimTemplates:
  - metadata:
      name: cassandra-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 10Gi

部署说明 #

• 采用StatefulSet保证Pod稳定网络标识与持久化存储，3副本适配你的3节点集群
• 通过环境变量配置集群核心参数，可根据集群资源实际情况调整CPU、内存限制
• 持久化存储使用PVC，按需修改存储容量

二、部署Elasticsearch #

1. StatefulSet与Service YAML #

apiVersion: v1
kind: Service
metadata:
  name: elasticsearch
  labels:
    app: elasticsearch
spec:
  clusterIP: None
  ports:
    - port: 9200
      name: rest
    - port: 9300
      name: inter-node
  selector:
    app: elasticsearch
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: elasticsearch
spec:
  serviceName: elasticsearch
  replicas: 3
  selector:
    matchLabels:
      app: elasticsearch
  template:
    metadata:
      labels:
        app: elasticsearch
    spec:
      initContainers:
      - name: fix-permissions
        image: busybox:1.36.1
        command: ["sh", "-c", "chown -R 1000:1000 /usr/share/elasticsearch/data"]
        securityContext:
          privileged: true
        volumeMounts:
        - name: es-data
          mountPath: /usr/share/elasticsearch/data
      - name: increase-vm-max-map
        image: busybox:1.36.1
        command: ["sysctl", "-w", "vm.max_map_count=262144"]
        securityContext:
          privileged: true
      containers:
      - name: elasticsearch
        image: docker.elastic.co/elasticsearch/elasticsearch:8.11.3
        ports:
        - containerPort: 9200
          name: rest
        - containerPort: 9300
          name: inter-node
        resources:
          limits:
            cpu: "1000m"
            memory: 2Gi
          requests:
            cpu: "500m"
            memory: 1Gi
        volumeMounts:
        - name: es-data
          mountPath: /usr/share/elasticsearch/data
        env:
          - name: node.name
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: cluster.name
            value: "K8sElasticCluster"
          - name: discovery.seed_hosts
            value: "elasticsearch-0.elasticsearch.default.svc.cluster.local,elasticsearch-1.elasticsearch.default.svc.cluster.local,elasticsearch-2.elasticsearch.default.svc.cluster.local"
          - name: cluster.initial_master_nodes
            value: "elasticsearch-0,elasticsearch-1,elasticsearch-2"
          - name: ES_JAVA_OPTS
            value: "-Xms1g -Xmx1g"
          - name: xpack.security.enabled
            value: "false"
  volumeClaimTemplates:
  - metadata:
      name: es-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 10Gi

部署说明 #

• 两个初始化容器分别修复存储目录权限、调整内核参数，满足Elasticsearch运行要求
• 关闭xpack.security便于测试，生产环境需开启并配置认证机制
• 3副本适配3节点集群，资源限制可根据实际情况调整

三、部署JanusGraph #

1. Deployment与Service YAML（基于Cassandra存储+Elasticsearch索引） #

apiVersion: v1
kind: Service
metadata:
  name: janusgraph
  labels:
    app: janusgraph
spec:
  type: NodePort
  ports:
    - port: 8182
      targetPort: 8182
      nodePort: 30082
  selector:
    app: janusgraph
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: janusgraph
spec:
  replicas: 1
  selector:
    matchLabels:
      app: janusgraph
  template:
    metadata:
      labels:
        app: janusgraph
    spec:
      containers:
      - name: janusgraph
        image: janusgraph/janusgraph:0.6.3
        ports:
        - containerPort: 8182
          name: gremlin
        resources:
          limits:
            cpu: "1000m"
            memory: 2Gi
          requests:
            cpu: "500m"
            memory: 1Gi
        env:
          - name: JANUSGRAPH_STORAGE_BACKEND
            value: "cassandra"
          - name: JANUSGRAPH_STORAGE_HOSTS
            value: "cassandra.default.svc.cluster.local"
          - name: JANUSGRAPH_INDEX_BACKEND
            value: "elasticsearch"
          - name: JANUSGRAPH_INDEX_HOSTS
            value: "elasticsearch.default.svc.cluster.local"
          - name: JAVA_OPTS
            value: "-Xms1g -Xmx1g"

部署说明 #

• 通过K8s内部服务名关联Cassandra存储与Elasticsearch索引后端
• 初始为单副本部署，可根据业务需求扩容
• 采用NodePort暴露服务便于外部访问，也可切换为ClusterIP或LoadBalancer类型

通用部署步骤 #

1. 将上述内容分别保存为cassandra.yaml、elasticsearch.yaml、janusgraph.yaml文件
2. 依次执行部署命令：

   kubectl apply -f cassandra.yaml
   kubectl apply -f elasticsearch.yaml
   kubectl apply -f janusgraph.yaml
   

3. 验证Pod运行状态：

   kubectl get pods
   

   等待所有Pod进入Running状态即可使用

注意事项 #

• 确保集群节点有足够CPU、内存资源，避免因资源不足导致Pod调度失败
• 生产环境建议配置自定义StorageClass，优化持久化存储性能与可靠性
• 可根据业务需求调整副本数、资源限制、存储容量等参数

内容的提问来源于stack exchange，提问作者syed adeeb