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Date: Wed, 20 Oct 2010 17:34:41 -0700
Message-ID: <AANLkTimToe6HFk+DcFdzyp5Cwv0E14bGOZ_mHCaGiM6N@mail.gmail.com>
Subject: Transaction/Locking Support
From: Wicked J <wickedj2010@gmail.com>
To: user@cassandra.apache.org
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Hi,
I'm trying to persist the contents of my app. objects to Cassandra. The
objects in here are loosely modeled on key value (KV) stores. If the KV
store is extended from HashMap and mapped to a ColumnFamily with put and get
ops mapping to insert/read from Cassandra. Then my questions are:

a) What operations in Cassandra can be considered to be atomic - reads? Is
reading (of rows by concurrent threads/clients) atomic across one Column
Family or across multiple (e.g. two) Column Families? assume
get_range_slices ..with ConsistencyLevel.QUORUM
b) Consistency of write/update/delete ops across CF's by concurrent
clients/threads? In order to make them consistent or atomic, would
insert(..) with ConsistencyLevel.QUORUM be a good idea. Or would you
recommend external components like ZooKeeper or Hazelcast etc to coordinate
such operations?

Thanks!

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Hi,<br>I&#39;m trying to persist the contents of my app. objects to Cassand=
ra. The objects in here are loosely modeled on key value (KV) stores. If th=
e KV store is extended from HashMap and mapped to a ColumnFamily with put a=
nd get ops mapping to insert/read from Cassandra. Then my questions are: <b=
r>
<br>a) What operations in Cassandra can be considered to be atomic - reads?=
 Is reading (of rows by concurrent threads/clients) atomic across one Colum=
n Family or across multiple (e.g. two) Column Families? assume get_range_sl=
ices ..with ConsistencyLevel.QUORUM<br>
b) Consistency of write/update/delete ops across CF&#39;s by concurrent cli=
ents/threads? In order to make them consistent or atomic, would insert(..) =
with ConsistencyLevel.QUORUM be a good idea. Or would you recommend externa=
l components like ZooKeeper or Hazelcast etc to coordinate such operations?=
<br>
<br>Thanks!<br>

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