ZooKeeper的Java API客戶端異常：org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorC
阿新 • • 發佈：2019-01-30
log4j:WARN No appenders could be found for logger (org.apache.zookeeper.ZooKeeper).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /servers/server
at org.apache.zookeeper.KeeperException.create(KeeperException.java:99)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
at org.apache.zookeeper.ZooKeeper.create(ZooKeeper.java:783)
at cn.itcast.bigdata.zkdist.DistributedServer.registerServer(DistributedServer.java:46)
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /servers/server
at org.apache.zookeeper.KeeperException.create(KeeperException.java:99)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
at org.apache.zookeeper.ZooKeeper.create(ZooKeeper.java:783)
at cn.itcast.bigdata.zkdist.DistributedServer.registerServer(DistributedServer.java:46)
at cn.itcast.bigdata.zkdist.DistributedServer.main(DistributedServer.java:68)
網上常見的解決方法是：關閉防火牆
但是防火牆就是處於關閉狀態，所以此方法不可用。
經過除錯發現 private static final int sessionTimeout = 10000 中設定的sessionTimeout值太小，應增大此值，問題解決。
解釋：sessionTimeout是會話超時時間，也就是當一個zookeeper超過該時間沒有心跳，則認為該節點故障。所以，如果此值小於zookeeper的建立時間，則當zookeeper還未來得及建立連線，會話時間已到，因此丟擲異常認為該節點故障。