zookeeper正常，kafka總是掛掉的問題：A broker is already registered on the path /brokers/ids/0.

打開zookeeper集群之后，zk正常，但是kafka啟動之后總是會掛掉，查找logs日志里的server.log文件發現問題：

 

 

問題：A broker is already registered on the path /brokers/ids/0. This probably indicates that you either have configured a brokerid that is already in use, or else you have shutdown this broker and restarted it faster than the zookeeper timeout so it appears to be re-registering.

這可能是之前機器因為卡死或物理重啟，kafka broker沒有正常下線，zk上還保留着它的broker id。所以直接刪除zk上的brokerid就可以了。

具體解決步驟如下：

1、進入zookeeper的客戶端

[admin@hadoop102 zookeeper-3.4.10]$ bin/zkCli.sh

2、進入客戶端以后查看注冊信息

[zk: localhost:2181(CONNECTED) 2] ls /

 

 3、進入brokers查看ids的信息

[zk: localhost:2181(CONNECTED) 10] ls /brokers/ids

 

4、刪除這些注冊信息就ok

[zk: localhost:2181(CONNECTED) 11] delete /brokers/ids

 

 

5、在開啟kafka，就沒問題了。