Part4 集群之多主多从.md

集群-多主多从模式

异步复制：主备有短暂消息延迟，出现磁盘故障消息丢失的非常少，且消息实时性不会受影响

同步双写：只有主备都写成功，才向应用返回成功，消息与服务都无单点故障，性能略低

1，服务器准备

    Broker Master1    192.168.140.156

    Broker Slave1     192.168.140.157

    Broker Master2    192.168.140.158

    Broker Slave2     192.168.140.159

    Name Server1      192.168.140.157

    Name Server2      192.168.140.159

2，分别修改 Broker Master 配置

    brokerClusterName=rocketmq-cluster
    brokerName=broker-node1
    brokerId=0
    namesrvAddr=192.168.140.157:9876;192.168.140.159:9876
    brokerRole=ASYNC_MASTER

    brokerClusterName=rocketmq-cluster
    brokerName=broker-node2
    brokerId=0
    namesrvAddr=192.168.140.157:9876;192.168.140.159:9876
    brokerRole=ASYNC_MASTER

3，分别修改 Broker Slave 配置

    brokerClusterName=rocketmq-cluster
    brokerName=broker-node1
    brokerId=1
    namesrvAddr=192.168.140.157:9876;192.168.140.159:9876
    brokerRole=SLAVE

    brokerClusterName=rocketmq-cluster
    brokerName=broker-node2
    brokerId=1
    namesrvAddr=192.168.140.157:9876;192.168.140.159:9876
    brokerRole=SLAVE

3，启动 Broker 和 Name Server

    nohup sh bin/mqnamesrv &

    nohup sh bin/mqbroker &

4，同步双写和异步复制

    两者配置的区别在于 Broker Master 节点 brokerRole 配置不同：

    brokerRole=SYNC_MASTER         #同步双写

    brokerRole=ASYNC_MASTER        #异步复制