Hi, The master have lost its connection to ZooKeeper. In this case it stops as the consistency of the cluster cannot be ensured. There are both a retry number and a timeout setting to control this, but it's not the root cause. The default is 10 tries and 3 minutes, so when it happens it means you have a serious issue. Note that the region servers will continue to work without the master. But may be they have lost their connection to ZK as well (in this case they will stop, for the same reason). You should have a look at how is the network between ZK and the master, or look after ZK logs to check that nobody killed it / killed them.
N. On Sat, May 26, 2012 at 3:22 AM, Something Something <[email protected]> wrote: > Hello, > > I recently installed ZooKeeper & HBase on our dedicated Hadoop cluster on > EC2. The HBase stays active for some time, but after a while it dies with > error messages similar to these: > > 2012-05-25 12:09:27,514 ERROR > org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher: > master:60000-0x5378489312c0004-0x5378489312c0004 Received unexpected > KeeperException, re-throwing exception > org.apache.zookeeper.KeeperException$ConnectionLossException: > KeeperErrorCode = ConnectionLoss for /hbase/master > at > org.apache.zookeeper.KeeperException.create(KeeperException.java:90) > at > org.apache.zookeeper.KeeperException.create(KeeperException.java:42) > at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:927) > at > org.apache.hadoop.hbase.zookeeper.ZKUtil.getDataAndWatch(ZKUtil.java:549) > at > org.apache.hadoop.hbase.zookeeper.ZKUtil.getDataAsAddress(ZKUtil.java:620) > at > org.apache.hadoop.hbase.master.ActiveMasterManager.stop(ActiveMasterManager.java:197) > at org.apache.hadoop.hbase.master.HMaster.run(HMaster.java:310) > 2012-05-25 12:09:27,514 ERROR > org.apache.hadoop.hbase.master.ActiveMasterManager: > master:60000-0x5378489312c0004-0x5378489312c0004 Error deleting our own > master address node > org.apache.zookeeper.KeeperException$ConnectionLossException: > KeeperErrorCode = ConnectionLoss for /hbase/master > at > org.apache.zookeeper.KeeperException.create(KeeperException.java:90) > at > org.apache.zookeeper.KeeperException.create(KeeperException.java:42) > at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:927) > at > org.apache.hadoop.hbase.zookeeper.ZKUtil.getDataAndWatch(ZKUtil.java:549) > at > org.apache.hadoop.hbase.zookeeper.ZKUtil.getDataAsAddress(ZKUtil.java:620) > at > org.apache.hadoop.hbase.master.ActiveMasterManager.stop(ActiveMasterManager.java:197) > at org.apache.hadoop.hbase.master.HMaster.run(HMaster.java:310) > > > This kills the HMaster as well as all HRegionServers. Could it be that my > ZooKeeper setup is incorrect? Please help. Thanks.
