rocketMQ 4.5.1 No route info of this topic

Question

rocketMQ 版本

4.5.1

集群配置

2m-2s

出现问题

客户端偶而出现：No route info of this topic

其他信息

1. topic 是有创建的，客户端出现这种情况是偶发

2. 在 rocketMQ namesrv 源码可以看到。当 pickupTopicRouteData 方法返回的值为 null 时，会返回刚才的报错信息给客户端

   public class DefaultRequestProcessor {
   public RemotingCommand getRouteInfoByTopic(ChannelHandlerContext ctx,
        RemotingCommand request) throws RemotingCommandException {
        final RemotingCommand response = RemotingCommand.createResponseCommand(null);
        final GetRouteInfoRequestHeader requestHeader =
            (GetRouteInfoRequestHeader) request.decodeCommandCustomHeader(GetRouteInfoRequestHeader.class);
   
        TopicRouteData topicRouteData = this.namesrvController.getRouteInfoManager().pickupTopicRouteData(requestHeader.getTopic());
   
        if (topicRouteData != null) {
            if (this.namesrvController.getNamesrvConfig().isOrderMessageEnable()) {
                String orderTopicConf =
                    this.namesrvController.getKvConfigManager().getKVConfig(NamesrvUtil.NAMESPACE_ORDER_TOPIC_CONFIG,
                        requestHeader.getTopic());
                topicRouteData.setOrderTopicConf(orderTopicConf);
            }
   
            byte[] content = topicRouteData.encode();
            response.setBody(content);
            response.setCode(ResponseCode.SUCCESS);
            response.setRemark(null);
            return response;
        }
   
        response.setCode(ResponseCode.TOPIC_NOT_EXIST);
        response.setRemark("No topic route info in name server for the topic: " + requestHeader.getTopic()
            + FAQUrl.suggestTodo(FAQUrl.APPLY_TOPIC_URL));
        return response;
    }
   }

3. 什么情况下 pickupTopicRouteData 会返回 null?

   public class RouteInfoManager {
   public TopicRouteData pickupTopicRouteData(final String topic) {
        TopicRouteData topicRouteData = new TopicRouteData();
        boolean foundQueueData = false;
        boolean foundBrokerData = false;
        Set<String> brokerNameSet = new HashSet<String>();
        List<BrokerData> brokerDataList = new LinkedList<BrokerData>();
        topicRouteData.setBrokerDatas(brokerDataList);
   
        HashMap<String, List<String>> filterServerMap = new HashMap<String, List<String>>();
        topicRouteData.setFilterServerTable(filterServerMap);
   
        try {
            try {
                this.lock.readLock().lockInterruptibly();
                List<QueueData> queueDataList = this.topicQueueTable.get(topic);
                if (queueDataList != null) {
                    topicRouteData.setQueueDatas(queueDataList);
                    foundQueueData = true;
   
                    Iterator<QueueData> it = queueDataList.iterator();
                    while (it.hasNext()) {
                        QueueData qd = it.next();
                        brokerNameSet.add(qd.getBrokerName());
                    }
   
                    for (String brokerName : brokerNameSet) {
                        BrokerData brokerData = this.brokerAddrTable.get(brokerName);
                        if (null != brokerData) {
                            BrokerData brokerDataClone = new BrokerData(brokerData.getCluster(), brokerData.getBrokerName(), (HashMap<Long, String>) brokerData
                                .getBrokerAddrs().clone());
                            brokerDataList.add(brokerDataClone);
                            foundBrokerData = true;
                            for (final String brokerAddr : brokerDataClone.getBrokerAddrs().values()) {
                                List<String> filterServerList = this.filterServerTable.get(brokerAddr);
                                filterServerMap.put(brokerAddr, filterServerList);
                            }
                        }
                    }
                }
            } finally {
                this.lock.readLock().unlock();
            }
        } catch (Exception e) {
            log.error("pickupTopicRouteData Exception", e);
        }
   
        log.debug("pickupTopicRouteData {} {}", topic, topicRouteData);
   
        if (foundBrokerData && foundQueueData) {
            return topicRouteData;
        }
   
        return null;
    }
   }

从代码，可以看到， 当 foundBrokerData && foundQueueData 值为 false 时，会返回 null.

4. 什么情况 foundBrokerData OR foundQueueData 会 null
   从代码看，加锁失败！ 或者方法执行失败会返回 null。 但是， 方法执行失败，这个根本不可能，也就是只能是加锁失败了。
5. 什么时候加锁会失败？？？？？？？

Answer 1

无语了：

同事连了 3 个 namesrv。 而其中 1个 namesrv 不在 集群中。
所以服务在启动的时候，可能会连接到 不在 集群中的 namesrv