I saw that wiki page. And I read this paragraph "It means that the client was partitioned off from the ZooKeeper service for more the the session timeout ..." That's why I use Expired event for cluster membership. In my case client is a node in a cluster.
2010/2/9 Patrick Hunt <ph...@apache.org> > this? "How should I handle SESSION_EXPIRED?" > http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A3 > > > Benjamin Reed wrote: > >> i was looking through the docs to see if we talk about handling session >> expired, but i couldn't find anything. we should probably open a jira to add >> to the docs, unless i missed something. did i? >> >> ben >> >> -----Original Message----- >> From: Mahadev Konar [mailto:maha...@yahoo-inc.com] Sent: Monday, February >> 08, 2010 2:43 PM >> To: zookeeper-user@hadoop.apache.org >> Subject: Re: When session expired event fired? >> >> Hi, >> a zookeeper client does not expire a session until and unless it is able >> to >> connect to one of the servers. In your case if you kill all the servers, >> the >> client is not able to connect to any of the servers and will keep trying >> to >> connect to the three servers. It cannot expire a session on its own and >> needs to hear from the server to know if the session is expired or not. >> >> Does that help? >> Thanks >> mahadev >> >> >> On 2/8/10 2:37 PM, "neptune" <opennept...@gmail.com> wrote: >> >> Hi all. >>> I have a question. I started zookeeper(3.2.2) on three servers. >>> When session expired event fired in following code? >>> I expected that if client can't connect to server(disconnected) for >>> session >>> timeout, zookeeper fires session expired event. >>> I killed three zookeeper server sequentially. Client retry to connect >>> zookeeper server. Never occured Expired event. >>> >>> *class WatcherTest { >>> public static void main(String[] args) { >>> (new **WatcherTest*()).exec(); >>> * } >>> >>> private WatcherTest() throws Exception { >>> zk = new ZooKeeper("server1:2181,server2:2181:server3:2181", 10 * >>> 1000, >>> this); >>> } >>> private void exec() { >>> while(ture) { >>> //do something >>> } >>> } >>> public void process(WatchedEvent event) { >>> if (event.getType() == Event.EventType.None) { >>> switch (event.getState()) { >>> case SyncConnected: >>> System.out.println("ZK SyncConnected"); >>> break; >>> case Disconnected: >>> System.out.println("ZK Disconnected"); >>> break; >>> case Expired: >>> System.out.println("ZK Session Expired"); >>> System.exit(0); >>> break; >>> } >>> } >>> } >>> * >>> >> >>
