Confluent Control Center on a cluster

Question

I've set up a basic three-server cluster of zookeeper and kafka version 5.4.0 using docker. For zookeeper and kafka, I've specified all three of the bootstrap servers. I'm trying to set this up in a manner that allows for one server to go down and the cluster will still operate correctly. I'm trying to get control center working and I'm running into problems. First, it seems as though only one of the servers is successfully able to run control center, and only when i specify the bootstrap server it's running on rather than all three. If I try to start control center on the other two servers, they fail to start and they continually log the following:

INFO unable to get command store (io.confluent.command.CommandStore)

I'm not certain how best to get this done. Since it may be helpful, I'm posting below my docker-compose files for the zookeeper/broker pair as well as the file for control center. Please let me know if I've got anything misspecified or if you think a change is in order.

zookeeper/kafka broker docker-compose.yml (the others differ only by advertised listener IP):

---
version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:5.4.0
    hostname: zookeeper
    container_name: zookeeper
    network_mode: host
    restart: always
    ports:
      - "2181:2181"
    environment:
      ZOOKEEPER_SERVER_ID: 2
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000
      ZOOKEEPER_INIT_LIMIT: 5
      ZOOKEEPER_SYNC_LIMIT: 2
      ZOOKEEPER_SERVERS: "10.100.1.1:2888:3888;10.100.1.2:2888:3888;10.100.1.3:2888:3888"
    volumes:
      - ./zk-data:/var/lib/zookeeper/data
      - ./zk-txn-logs:/var/lib/zookeeper/log

  broker:
    image: confluentinc/cp-enterprise-kafka:5.4.0
    hostname: broker
    container_name: broker
    depends_on:
      - zookeeper
    network_mode: host
    restart: always
    ports:
      - "9092:9092"
    environment:
      KAFKA_BROKER_ID: 2
      KAFKA_ZOOKEEPER_CONNECT: '10.100.1.1:2181,10.100.1.2:2181,10.100.1.3:2181'
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: "PLAINTEXT://10.100.1.1:9092"
      KAFKA_METRIC_REPORTERS: io.confluent.metrics.reporter.ConfluentMetricsReporter
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 2
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
      CONFLUENT_METRICS_REPORTER_BOOTSTRAP_SERVERS: 10.100.1.1:9092,10.100.1.2:9092,10.100.1.3:9092
      CONFLUENT_METRICS_REPORTER_ZOOKEEPER_CONNECT: 10.100.1.1:2181,10.100.1.2:2181,10.100.1.3:2181
      CONFLUENT_METRICS_REPORTER_TOPIC_REPLICAS: 2
      CONFLUENT_METRICS_ENABLE: 'true'
      CONFLUENT_SUPPORT_CUSTOMER_ID: 'anonymous'
    volumes:
      - ./kafka-data:/var/lib/kafka/data

control center docker-compose.yml:

---
version: '2'
services:
  control-center:
    image: confluentinc/cp-enterprise-control-center:5.4.0
    hostname: control-center
    container_name: control-center
    network_mode: host
    restart: always
    ports:
      - "9021:9021"
    environment:
      CONTROL_CENTER_BOOTSTRAP_SERVERS: '10.100.1.1:9092'
      CONTROL_CENTER_ZOOKEEPER_CONNECT: '10.100.1.1:2181'
      CONTROL_CENTER_REPLICATION_FACTOR: 1
      CONTROL_CENTER_INTERNAL_TOPICS_PARTITIONS: 1
      CONTROL_CENTER_MONITORING_INTERCEPTOR_TOPIC_PARTITIONS: 1
      CONFLUENT_METRICS_TOPIC_REPLICATION: 1
      PORT: 9021
    volumes:
      - ./control-center:/var/lib/confluent-control-center

Answer 1

1) remove network_mode: host

2l Add control center to the same compose file

3) use zookeeper:2181 for the Zookeeper connection strings and kafka:9092 for the bootstrap servers. I don't think metrics reporters or control center have a Zookeeper property

---

If you want to create a cluster of containers, then you probably want to take a look at the Confluent Helm Charts rather than the Docker compose files