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The "ZooKeeper/HBaseUseCases" page has been changed by stack. http://wiki.apache.org/hadoop/ZooKeeper/HBaseUseCases?action=diff&rev1=14&rev2=15 -------------------------------------------------- === root-region-server === This znode holds the location of the server hosting the root of all tables in hbase. - Idea is to hoist the whole region up into zk rather than have it out as a fully-fledged hbase region; it has little info in it. - === master === - This is current master. If more than one master, they fight over who it should be. They all try to grab this znode. + This is current master. If more than one master, they fight over who it should be. They all try to grab this znode. When this node evaporates, masters try to grab it again. Whoever wins picks up the master role. === rs === A directory in which there is a znode per hbase server (regionserver) participating in the cluster. They register themselves when they come on line. They name of the znode is a random number, the regions' startcode, so can tell if regionserver has been restarted (We should fix this so server names are more descriptive). + + If regionserver session in zk is lost, this znode evaporates. The regionserver will get the disconnect message and shut itself down. Master will start the clean up process gathering its write-ahead logs, splitting them and divvying the edits out per region so they are available when regions are opened in new locations on other running regionservers. === shutdown === If cluster is to shutdown.
