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The following page has been changed by stack: http://wiki.apache.org/hadoop/Hbase/Migration The comment on the change is: minor edit ------------------------------------------------------------------------------ * All hbase data and state is out on the FileSystem: Moving from one version should be just a case of moving or rewriting files on the FileSystem. * Hbase cannot be running when a migration is run. - * This can be tricky to assert when the hbase versions differ to such an extent, they are unable to talk to each other (Caller just hangs and eventually timesout). + * This can be tricky to assert when the hbase versions differ to the extent that they are unable to talk to each other (Caller just hangs and eventually timesout). * Sometimes, the amount of on-filesystem data that needs to be changed will be large so migration will need to run a MR job. * hbase FS image needs versioning. On startup, hbase will check the FS version. If awry, hbase will shut itself down emitting a migration needed message. Versions are finer-grained than release number. * The commit of every incompatible change would be accompanied by a script that can move hbase across the incompatibility.
