Hi guys: I find a very strange scenario today, I'm not sure how it happen, I just found it like this. Maybe you can give me some information about it, my Zookeeper Server is version 3.2.1.
My Zookeeper cluster contains three servers, with ip: 10.81.12.144,10.81.12.145,10.81.12.141. I wrote a client to create ephemeral node under znode: *se/diserver_tc*. The client runs on the server with ip 10.81.13.173. The client can create a ephemeral node on zookeeper server and write the host ip (10.81.13.173) in to the node as its data. There is only one client process can be running at a time, because the client will listen to a certain port. It is strange that I found there were two ephemeral node with the ip 10.81.13.173 under znode se/diserver_tc. *se/diserver_tc/diserver_tc0000000067* STAT: czxid: 124554079820 mzxid: 124554079820 ctime: 1260609598547 mtime: 1260609598547 version: 0 cversion: 0 aversion: 0 ephemeralOwner: 226627854640480810 dataLength: 92 numChildren: 0 pzxid: 124554079820 *se/diserver_tc/diserver_tc0000000095 *STAT: czxid: 128849019107 mzxid: 128849019107 ctime: 1260772197356 mtime: 1260772197356 version: 0 cversion: 0 aversion: 0 ephemeralOwner: 154673159808876591 dataLength: 92 numChildren: 0 pzxid: 128849019107* * There are TWO with different session id! And after I kill the client process on the server 10.81.13.173, the *se/diserver_tc/diserver_tc0000000095 *node disappear, but the *se/diserver_tc/diserver_tc0000000067 *stay the same. That means it is not my coding mistake to create the node twice. I checked several times and I'm sure that there is no another client instance running. And I use the 'stat' command to check the three zookeeper servers, and there is no client from 10.81.13.173, $echo stat | nc 10.81.12.144 2181 Zookeeper version: 3.2.1-808558, built on 08/27/2009 18:48 GMT Clients: /10.81.13.173:35676[1](queued=0,recved=0,sent=0) *# it is caused by the nc process* Latency min/avg/max: 0/3/254 Received: 11081 Sent: 0 Outstanding: 0 Zxid: 0x1e000001f5 Mode: follower *Node count: 32 * $ echo stat | nc 10.81.12.141 2181 Zookeeper version: 3.2.1-808558, built on 08/27/2009 18:48 GMT Clients: /10.81.12.152:58110[1](queued=0,recved=10374,sent=0) /10.81.13.173:35677[1](queued=0,recved=0,sent=0) *# it is caused by the nc process* Latency min/avg/max: 0/0/37 Received: 37128 Sent: 0 Outstanding: 0 Zxid: 0x1e000001f5 Mode: follower *Node count: 26* $ echo stat | nc 10.81.12.145 2181 Zookeeper version: 3.2.1-808558, built on 08/27/2009 18:48 GMT Clients: /10.81.12.153:19130[1](queued=0,recved=10624,sent=0) /10.81.13.173:35678[1](queued=0,recved=0,sent=0) *# it is caused by the nc process* Latency min/avg/max: 0/2/213 Received: 26700 Sent: 0 Outstanding: 0 Zxid: 0x1e000001f5 Mode: leader *Node count: 26* The three 'stat' commands show different Node count! Just cannot understand how it happened, can anyone give me some explanation about it? -- With Regards! Ye, Qian Made in Zhejiang University