mq消息消费,broker选址
PullRequest.MessageQueue.BrokerName
根据PullRequest.MessageQueue得到brokerId,默认0或者用缓存中的suggest,每次消息拉取后会更新sugestBrokerId到缓存,
BorkerName+brokerId在缓存(brokerAddrTable)中找到broker的地址
PullRequest在每20s的重平衡加入,MessageQueue是从NameServer取得的topic的订阅信息中拿到
消息发送:
1.TopicPublishInfo.MessageQueue
2.MessageQueue.brokerName
3.private final ConcurrentMap<String/* Broker Name */, HashMap<Long/* brokerId */, String/* address */>> brokerAddrTable =
new ConcurrentHashMap<String, HashMap<Long, String>>();
brokerAddrTable.get(brokerName).get(0)
看下发送时如何负载均衡的,可以看到如果发生重试(lastBrokerName 不为null)优先选上次失败的brokerName。否则逐个轮询