cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Trivial Update of "HintedHandoff_JP" by MakiWatanabe
Date Sat, 05 Feb 2011 07:11:03 GMT
Dear Wiki user,

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

The "HintedHandoff_JP" page has been changed by MakiWatanabe.
http://wiki.apache.org/cassandra/HintedHandoff_JP?action=diff&rev1=7&rev2=8

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

  CassandraはHinted Handoffを次の目的で使用しています。
  
   1.一時的障害により他のレプリカとの一貫性を失ったノードが稼働中のレプリカと再同期するのに必要な時間を短縮する
-  2.一貫性の要求が低いシステムにおいて、極めて高い書き込み可用性を提供する
+  1.一貫性の要求が低いシステムにおいて、極めて高い書き込み可用性を提供する
  
  A hinted write does NOT count towards ConsistencyLevel requirements of ONE, QUORUM, or ALL.
Take the simple example of a cluster of two nodes, A and B, and a replication factor of 1
(each key is stored on one node). Suppose node A is down while we write key K to it with ConsistencyLevel.ONE.
Then we must fail the write: recall from the API page that "if W + R >ReplicationFactor,
where W is the number of nodes to block for on write, and R the number to block for on reads,
you will have strongly consistent behavior; that is, readers will always see the most recent
write."
  

Mime
View raw message