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From "Dan Hendry" <dan.hendry.j...@gmail.com>
Subject RE: Data distribution
Date Tue, 15 Feb 2011 00:58:16 GMT
> 1) If I insert a key and want to verify which node it went to then how do
I
> do that?

I don't think you can and there should be no reason to care. Cassandra
abstracts where data is being stored, think in terms of consistency levels
not actual nodes. 

> 2) How can I verify if the replication is working. That is how do I check
> that CF row got inserted in 2 nodes if replication factor is set to 2.

Perform a successful write at consistency level ALL via a thrift client.

> 3) What happens if I just update the keyspace and change the replication
> factor say 2 to 3. Would cassandra automatically replicate the old data to
> the 3rd node?

http://wiki.apache.org/cassandra/Operations#Replication

"but increasing it may be done if you (a) read at ConsistencyLevel.QUORUM or
ALL (depending on your existing replication factor) to make sure that a
replica that actually has the data is consulted, (b) are willing to accept
downtime while anti-entropy repair runs (see below), or (c) are willing to
live with some clients potentially being told no data exists if they read
from the new replica location(s) until repair is done."

Dan

-----Original Message-----
From: mcasandra [mailto:mohitanchlia@gmail.com] 
Sent: February-14-11 19:45
To: cassandra-user@incubator.apache.org
Subject: Data distribution


Couple of questions:

1) If I insert a key and want to verify which node it went to then how do I
do that?
2) How can I verify if the replication is working. That is how do I check
that CF row got inserted in 2 nodes if replication factor is set to 2.
3) What happens if I just update the keyspace and change the replication
factor say 2 to 3. Would cassandra automatically replicate the old data to
the 3rd node?
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