MQ常见问题

1.  sh bin/mqadmin topicList 命令发生错误，错误如下：

org.apache.rocketmq.remoting.exception.RemotingConnectException: connect to <null> failed
	at org.apache.rocketmq.remoting.netty.NettyRemotingClient.invokeSync(NettyRemotingClient.java:357)
	at org.apache.rocketmq.client.impl.MQClientAPIImpl.getTopicListFromNameServer(MQClientAPIImpl.java:1219)
	at org.apache.rocketmq.tools.admin.DefaultMQAdminExtImpl.fetchAllTopicList(DefaultMQAdminExtImpl.java:220)
	at org.apache.rocketmq.tools.admin.DefaultMQAdminExt.fetchAllTopicList(DefaultMQAdminExt.java:183)
	at org.apache.rocketmq.tools.command.topic.TopicListSubCommand.execute(TopicListSubCommand.java:105)
	at org.apache.rocketmq.tools.command.MQAdminStartup.main0(MQAdminStartup.java:128)
	at org.apache.rocketmq.tools.command.MQAdminStartup.main(MQAdminStartup.java:78)

解决办法： export NAMESRV_ADDR=localhost:9876 之后在进行查询