使KSQLDB集群在拉取查询方面具有高可用性。

为了使KSQLDB集群在拉取查询方面具有高可用性，可以考虑在每个KSQLDB实例中设置拉取查询服务的副本，使其能够对查询服务的故障进行容错，并在整个集群中动态分配流量，从而避免任何一个实例的过载。我们可以按照以下步骤实现这一目标：

1.首先，我们需要采用Docker Compose部署具有三个KSQLDB实例的集群，以实现高可用性和容错性。以下是docker-compose.yml文件的示例：

version: '2' services: broker-1: image: confluentinc/cp-kafka:latest hostname: broker-1 container_name: broker-1 environment: KAFKA_BROKER_ID: 1 KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181 KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://broker-1:9092 KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 3 KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 3 KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 2 volumes: - kafka-data-1:/var/lib/kafka/data ports: - "9092:9092" broker-2: image: confluentinc/cp-kafka:latest hostname: broker-2 container_name: broker-2 environment: KAFKA_BROKER_ID: 2 KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181 KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://broker-2:9092 KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 3 KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 3 KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 2 volumes: - kafka-data-2:/var/lib/kafka/data ports: