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From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Trivial Update of "Operations" by CathyDaw
Date Thu, 21 Apr 2011 00:15:49 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Cassandra Wiki" for change notification.

The "Operations" page has been changed by CathyDaw.
http://wiki.apache.org/cassandra/Operations?action=diff&rev1=84&rev2=85

--------------------------------------------------

        for x in xrange(nodes):         
            print 2 ** 127 / nodes * x
  
- In versions of cassandra 0.7.* and lower, there's also `nodetool loadbalance`: essentially
a convenience over decommission + bootstrap, only instead of telling the target node where
to move on the ring it will choose its location based on the same heuristic as Token selection
on bootstrap. You should not use this as it doesn't rebalance the entire ring. 
+ In versions of Cassandra 0.7.* and lower, there's also `nodetool loadbalance`: essentially
a convenience over decommission + bootstrap, only instead of telling the target node where
to move on the ring it will choose its location based on the same heuristic as Token selection
on bootstrap. You should not use this as it doesn't rebalance the entire ring. 
  
- The status of move and balancing operations can be monitored using `nodetool` with the `streams`
argument.
+ The status of move and balancing operations can be monitored using `nodetool` with the `netstat`
argument. 
+ (Cassandra 0.6.* and lower use the `streams` argument).
  
  == Consistency ==
  Cassandra allows clients to specify the desired consistency level on reads and writes. 
(See [[API]].)  If R + W > N, where R, W, and N are respectively the read replica count,
the write replica count, and the replication factor, all client reads will see the most recent
write.  Otherwise, readers '''may''' see older versions, for periods of typically a few ms;
this is called "eventual consistency."  See http://www.allthingsdistributed.com/2008/12/eventually_consistent.html
and http://queue.acm.org/detail.cfm?id=1466448 for more.

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