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From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Update of "CassandraHardware" by JonathanEllis
Date Fri, 26 Mar 2010 21:57:13 GMT
Dear Wiki user,

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

The "CassandraHardware" page has been changed by JonathanEllis.
The comment on this change is: r/m mostly-obsolete section about needing equal hardware.
http://wiki.apache.org/cassandra/CassandraHardware?action=diff&rev1=10&rev2=11

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

- === General ===
- 
- Cassandra assumes that all nodes have equal capacity.  Violating this assumption will lead
to poor performance.  Rather than keeping your hardware price fixed and adding increasingly
powerful machines as moore's law kicks in, keep capacity (relatively) fixed and add increasingly
inexpensive ones.  (This is easier if you start with relatively powerful machines.)
- 
  === Memory ===
  The most recently written data resides in memory tables (aka [[MemtableThresholds|memtables]]),
but older data that has been flushed to disk can be kept in the OS's file-system cache. In
other words, ''the more memory, the better'', with 1GB being the minimum we typically recommended
in a virtualized environment.  Obviously there is no benefit to having more RAM than your
hot data set, but with dedicated hardware there is no reason to use less than 4GB, and at
the high end, you see clusters with 16 or 32 GB or more per node.
  

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