zooKeeper3.9集群docker-compose搭建

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1. 架构设计说明

1.1 集群拓扑

  • 3 节点 ZooKeeper（奇数节点，避免脑裂）

  • 使用 同一 Docker 网络

  • 每个节点：

    • 独立 dataDir
    • 独立 dataLogDir
    • 明确 myid

  • 暴露：

    • clientPort：2181
    • follower 通信：2888
    • leader 选举：3888

1.2 通信关系

graph TD
    C[Client] --> ZK1[ZooKeeper-1]
    C --> ZK2[ZooKeeper-2]
    C --> ZK3[ZooKeeper-3]

    ZK1 <--> ZK2
    ZK2 <--> ZK3
    ZK1 <--> ZK3

2. 目录结构规划

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zookeeper/
├── docker-compose.yml
├── zk1/
│   └── data/
├── zk2/
│   └── data/
├── zk3/
│   └── data/

说明：

  • myid 会自动写入 data/myid
  • 日志与快照统一放在 /data

3. docker-compose.yml

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version: "3.8"

networks:
  zk-net:
    driver: bridge

services:
  zk1:
    image: zookeeper:3.9
    container_name: zk1
    hostname: zk1
    restart: always
    ports:
      - "2181:2181"
    environment:
      ZOO_MY_ID: 1
      ZOO_SERVERS: >
        server.1=zk1:2888:3888;2081
        server.2=zk2:2888:3888;2081
        server.3=zk3:2888:3888;2081
      ZOO_MAX_CLIENT_CNXNS: 1000
      JVMFLAGS: "-Xms512m -Xmx512m"
    volumes:
      - ./zk1/data:/data
    networks:
      - zk-net

  zk2:
    image: zookeeper:3.9
    container_name: zk2
    hostname: zk2
    restart: always
    ports:
      - "2182:2181"
    environment:
      ZOO_MY_ID: 2
      ZOO_SERVERS: >
        server.1=zk1:2888:3888;2081
        server.2=zk2:2888:3888;2081
        server.3=zk3:2888:3888;2081
      ZOO_MAX_CLIENT_CNXNS: 1000
      JVMFLAGS: "-Xms512m -Xmx512m"
    volumes:
      - ./zk2/data:/data
    networks:
      - zk-net

  zk3:
    image: zookeeper:3.9
    container_name: zk3
    hostname: zk3
    restart: always
    ports:
      - "2183:2181"
    environment:
      ZOO_MY_ID: 3
      ZOO_SERVERS: >
        server.1=zk1:2888:3888;2081
        server.2=zk2:2888:3888;2081
        server.3=zk3:2888:3888;2081
      ZOO_MAX_CLIENT_CNXNS: 1000
      JVMFLAGS: "-Xms512m -Xmx512m"
    volumes:
      - ./zk3/data:/data
    networks:
      - zk-net

4. 启动与验证

4.1 启动

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docker-compose up -d

4.2 查看状态

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docker ps

4.3 验证角色（Leader / Follower）

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mac@GaGa ~ % for id in 1 2 3; do  docker exec -it zk${id} bash -c "./bin/zkServer.sh status"; done

JMX enabled by default
Using config: /conf/zoo.cfg
Mode: follower
JMX enabled by default
Using config: /conf/zoo.cfg
Mode: follower
JMX enabled by default
Using config: /conf/zoo.cfg
Mode: leader

你应该看到：

  • 1 个 Mode: leader
  • 2 个 Mode: follower

5. 生产级优化建议

5.1 JVM 内存限制

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environment:
  JVMFLAGS: "-Xms512m -Xmx512m"

5.2 磁盘 IO 分离

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volumes:
  - ./zk1/data:/data
  - ./zk1/datalog:/datalog

并加：

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ZOO_DATA_LOG_DIR: /datalog

5.3 Tick & 会话调优

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ZOO_TICK_TIME: 2000
ZOO_INIT_LIMIT: 10
ZOO_SYNC_LIMIT: 5
ZOO_MAX_CLIENT_CNXNS: 200