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The "Hbase/MasterRewrite" page has been changed by stack. http://wiki.apache.org/hadoop/Hbase/MasterRewrite?action=diff&rev1=15&rev2=16 -------------------------------------------------- * [[#root|Remove Heartbeat]] * [[#root|Remove Safe Mode]] * [[#intermediary|Further remove Master as necessary intermediary]] + * [[#misc|Miscellaneous]] <<Anchor(now)>> @@ -120, +121 @@ /hbase/regions/<regionserver by host:port:startcode>/<regionXYZ> # znode for each region assigned to RS host:port. # RS host:port watches this node in case reassigned by master, or region changes state - # /tables/<regionserver by host:port:startcode>/<regionXYZ>/<state>-<seq#> # znode created by master # seq ensures order seen by RS # RS deletes old state znodes as it transitions out, oldest entry is the current state, always 1 or more znode here -- the current state }}} - ====== Questions ====== + ====== Outstanding ====== - - Should the region znode have state? E.g. no flush, no compaction so we could do a backup by copying a region at a time? - - <<Anchor(clean)>> - - === Region State changes are clean, minimal, and comprehensive === - Currently, moving a region from ''opening'' to ''open'' may involve a region compaction -- i.e. a change to content in filesystem. Better if modification of filesystem content was done when no question of ownership involved. In current o.a.h.h.master.RegionManager.RegionState inner class, here are possible states: {{{ @@ -146, +139 @@ private volatile boolean offlined = false; }}} - TODO: Its incomplete. + Are all needed? What would we add? + + <<Anchor(clean)>> + + === Region State changes are clean, minimal, and comprehensive === + Currently, moving a region from ''opening'' to ''open'' may involve a region compaction -- i.e. a change to content in filesystem. Better if modification of filesystem content was done when no question of ownership involved. <<Anchor(balancer)>> @@ -203, +201 @@ <<Anchor(misc)>> == Miscellaneous == - * At meetup we talked of moving .META. to zk and adding a getClosest to zk code base. Thats been punted on for now. - * At meetup we had design numbers but they don't make sense now we've lost the context - 1. 200 regionservers - 1. 32 outstanding wal logs per regionserver - 1. 200 regions per regionserver being written to - 1. 2GB or 30 hour full log roll - 1. 10MB/sec write speed - 1. 1.2M edits per 2G - 1. 7k writes/second across cluster (?) -- whats this? Wrong. - 1. 1.2M edits per 30 hours? - 1. 100 writes/sec across cluster (?) -- Whats this? Wrong?
