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From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Update of "API" by BlairZajac
Date Thu, 24 Nov 2011 01:42:00 GMT
Dear Wiki user,

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

The "API" page has been changed by BlairZajac:
http://wiki.apache.org/cassandra/API?action=diff&rev1=29&rev2=30

Comment:
For read consistency level THREE, correct s/2/3/

  ||`ANY` ||Not supported. You probably want ONE instead. ||
  ||`ONE` ||Will return the record returned by the first replica to respond. A consistency
check is always done in a background thread to fix any consistency issues when `ConsistencyLevel.ONE`
is used. This means subsequent calls will have correct data even if the initial read gets
an older value.  (This is called ReadRepair) ||
  ||`TWO` ||Will query 2 replicas and return the record with the most recent timestamp.  Again,
the remaining replicas will be checked in the background. ||
- ||`THREE` ||Will query 2 replicas and return the record with the most recent timestamp.
||
+ ||`THREE` ||Will query 3 replicas and return the record with the most recent timestamp.
||
  ||`QUORUM` ||Will query all replicas and return the record with the most recent timestamp
once it has at least a majority of replicas (`N / 2 + 1`) reported.  Again, the remaining
replicas will be checked in the background. ||
  ||`LOCAL_QUORUM` ||Returns the record with the most recent timestamp once a majority of
replicas within the local datacenter have replied. ||
  ||`EACH_QUORUM` ||Returns the record with the most recent timestamp once a majority of replicas
within each datacenter have replied. ||

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